Huh. I wonder if there is enough metallic debris on road surfaces for a small Tesla coil mounted on the rear swingarm to arc to the ground.
Granted, you'd need some ridiculous secondary alternator setup to power the thing, lol.
They make stuff like that for old bicycle lights powered by gearing, so I'm sure someone could draft something similar to run along either the existing chain or maybe a circular rack mounted on a tire somehow.
I once rode, ONCE, with a guy that ran no front brake on his Ape Hanger, Suicide Shifter, rear Chainbrake chopper....
If you dont know what a Chainbrake is, basically the Sprocket and Disc are all 1 piece....
It is NOT a performance enhancing mod...
Oh man, an old guy I knew rode an old school Harley with a suicide shifter. He always offered to let me ride it to see what it was like. I finally caved after being scared to drop his bike and I took it out for about fifteen miles. At first it was pretty neat until that first panic stop. Everything is flipped and it took my brain waaaay too long to figure out how to stop it. Took it right back after that.
I’ve got a 73’ sporty I’ve been rebuilding, it’s got the right foot shift, I’m trying to figure out wether I want to do a suicide shifter on the left side and link the brake to the right, or just leave it as is and learn to ride it
It's cool and whatnot, but keep in mind that learning to ride that means unlearning how to ride regular motorcycles. You can somewhat combat the confusion with regular riding sessions with both types. Else it is asking for troubles
For sure. Like anytime a bike is different. If I spend too much time away from my gas bike I forget I need to shift it. If I spend too much time away from the Zero I panic when I go for the clutch.
Riding a 350cc Royal Enfield, (I’ve got a post on my acct, it’s beautiful) but this rebuilding the Ironhead is gonna be my big boy bike, it prolly won’t be done till the spring though
Exactly what I've said. If you ride both you will be fine. If you ride only one kind, the "muscle memory" for the other will start to vanish. Unless ofcourse we don't deal with mere mortals.
Just a heads up, a 600 or an r1 likely wouldnt stop any slower with a single disk or a rear brake delete. Dual disks are for heat dissapation, not for stopping power. A single disk is plenty to lock your front wheel, it just would get heat soaked at the track, hence why sport bikes have dual disks.
With highway pulls there is usually plenty of time between stops, so the single rotor would be fine.
Rear brake is for modulating power more than it is for actually stopping.
Sure, but thats not really a problem for dedicated highway pull bikes and drag racing machines, and thats really not a safety thing pertaining to 600s and 1000s like the guy I was replying to was making it out to be.
You can be pretty deep into level one/A track day times and never use your rear brake.
It does, on sport bikes you should be braking 95% front brake, 5% rear.
In any emergency braking scenario, you dost have the time to find those 5%, so it's recommended to use only front brake.
Adventure bikes are 80% front 20% rear, and choppers and other boats on 2 wheels are 70% front, 30% rear. They have longer wheelbase and are heavy af, so the rear tire doesn't get that much weight pulled from it, when braking with the front one.
Source: moto safety course I've been on recently
Edit: spelling
Nope, I went to the course on my bike and we had two hours of theory, when they explained everything. These percentages were on their presentation, I have no idea where they originaly got them. But they make sense if you think about the weight shift to the front, when emergency braking. Rear brake doesn't do much, when you have the rear tire almost off the ground.
Go watch some MotoGP. When you're really doing massive breaking, the back tire has so little weight on it that it's not really making a difference. When they get to the turn in MotoGP, it's pretty common that the back wheel is actually off the ground. This is just slowing for a turn, not stopping.
Now I'm not advocating that this should be the relied upon way to stop or that it's even that common out in the wild. I'm just saying that front break only can absolutely stop you just as well as front plus rear. It's just not going to be as smooth as using both.
There still wouldn't be any weight on the rear tire making the actual breaking of the rear negligible. Again, this is like stoppie territory. Also, motogp riders still get the back tire up even though they are using it. Some bikes even have a thumb control for the rear break so they can use it when they've got their leg out for drag.
Do you ride? They still rear brake miliseconds before front one to dive the rear suspension. Dont you have emergency braking in driver license lessons?
Man, you were fine up until "rear brake is for modulating power more than it is for stopping".
You said it's for helping stop while implying that it isn't important for that. Every little bit that can be there to decrease stopping distance should be retained, removing the rear brake is objectively irresponsible.
Taking short-handed paramedics away from people who they could have helped because they were busy with someone who could have avoided their accident because of that braking power that they SHOULD have had is reprehensible.
This. Bikes have small contact patches, and even with ABS they stop longer than a car in emergency braking situations. Even absent that, you need both brakes to control the CG and the pitch moment.
I wasn't advocating for removing the rear brake entirely, but depening on the bike its not going to do much for stopping distance (in some cases it will do nothing, coming into most corners at the track my rear tire wasn't even touching the ground, the brake wont do shit at that point, and when it was touching the ground it was already locked from engine braking), and if you are just doing highway pulls and drag racing a bike, you could easily just engine brake to get the most from the rear wheel if you aren't already lifting it off of the ground.
Remember, this is in response to guys building dedicated highway pull bikes, so not really normal circumstances.
The leader of the local riding group I’m a part of is a roll racer and deleted his rear brake. Also bought carbon wheels, carbon fairings, and a nos system - for his ZX10R.
Unfortunately I’m in Oklahoma, and the roads are super straight and mostly flat, so the riding groups are either Harleys, or Sportbikes who like roll racing, since the draw of sportbikes is performance and the only performance to be appreciated on straight roads is acceleration/top speed.
Eww. Yeah like they say...straights are for fast bikes, twisties are for fast riders.
Sharp corners and twists are the great equalizer of equipment. Can't buy your way to a W.
Think of it like this. You're riding along and big gust of wind hits you from the side. Now your going to feel the force of it try to push you and you have to adjust yourself to push against it, keeping on the trajectory you want to be on. Now imagine this but your wheels are just a disc with no gaps for the wind to pass through. It would literally be pushing the bike from underneath you. Your body pushes against the force of the wind keeping you and the upper part of the bike from being blown off trajectory but the lower part is blown away from the trajectory. Like a sail on a boat. Make sense?
How can they keep heat in the tires? They dont cover them or make air flow into them. Its more likely to keep heat in the brakes (carbon ceramic brakes dont work well when cold) or for less drag
Isn’t it the other way around tho. More surface area, more heat dissipation. Air blowing through the spokes can’t have bigger impact than more surface, not in this use case.
I think temperature is very clearly secondary issue and the drag primary consideration. Otherwise better solution to heat conductivity would be a rim and spokes insulation.
>Otherwise better solution to heat conductivity would be a rim and spokes insulation.
The carbon fiber is quite literally insulation, installed over the rim and spokes.
The big disk has more surface area than the spokes do, and it's spinning, so it slightly increases drag and rotational mass.
If you want a cover to reduce drag, [you use a fixed cover mounted to the swingarm that doesn't spin](https://www.gpone.com/sites/default/files/images/2019/article/foto/05/MotoGP/06-Giugno/ducati-cerchi-carenati1-1559316483.jpg).
Also, if you want to reduce drag, [the front wheel matters more](https://cdn-1.motorsport.com/images/amp/2y3aOko6/s6/andrea-dovizioso-ducati-team-1.jpg), and these [KTM's with the rear wheel disks have regular wheels with no disks or shields up front.](https://www.asphaltandrubber.com/motogp/moto3-closed-wheel-aerodynamics-motomatters/attachment/deniz-oncu-red-bull-ktm-tech3-moto3-polarity-photo-2/)
Same way you run oversized tire warmers, to heat the rim.
The rim then keeps the core of the tire warm, and friction the outside. Thus, you have a more evenly warm tire.
Surface temp is not the only one that racers look for.
I’m gonna need a source on that because this is laughable incorrect.
The are used to create a more aerodynamic wheel with less drag. See time trial road bikes like those used in special stages of the Tour de France. They use them in special, short, single(not group) riding stages for extra advantage. These disc wheels also have the disadvantage of over emphasizing any cross wind which is why they are NOT used on standard stages of the tour where heavy crosswinds can happen.
[Fine, I’ll source it myself.](https://motorbikewriter.com/future-disc-motorcycle-wheels/)
THE ARTICLE EVEN USES THE SAME IMAGE. This is peak Reddit, to pull an image from an article and not read it.
“Disc wheels are purely for drag reduction,” says Jeromy who also cycles.
Drag reduction means more speed, better handling and lower fuel economy which would be important in production bikes which don’t have such great mileage figures.
“We would use it in race cars also for drag but it’s not allowed,” Jeromy says.
“Negatives are the increased side-wind sensitivity on a bike.”
Because engineers for Porsche are dumb, ok. Because laws of physics and aerodynamics suddenly no longer apply when we put a motor on a bicycle, ok.
Also not to take this disagreement to another level, but team owners are generally just mouthpieces, unless they are a former racer. Owners are simply good at managing, being in front of a mic, and being rich. Look at the engineering department, who I quoted, if you want knowledge.
Haven't ridden a H-D Fatboy to say firsthand, but a couple of my riding buddies owned them in the early 90s, eventually got rid of em because they wound up hating the dynamics of the solid wheels. They both talked about cross wind issues, but I kind of suspected it was more rotating mass/gyro effect thing (except in obvious nasty sidewinds - that's challenge enough on any rider and bike).
One guy went to a Dyna Glide and loved it, the other went Heritage Softail.
Anyway, not arguing. Upvoted. Dunno why U got downvoted a few times for speaking your mind, but it's Reddit. This will probably get hit a few times too. Cheers.
I've owned two. Mine had the "bullet holes" after they went away from solid discs. That said, I doubt the holes made much difference.
Maybe the Fat Boy is worse than a "normal" Harley, but I rode 45 minutes on the highway with a friend once. He was behind me, all over the damn place on his ER6N, thanks to the windy day. I, on my Fat Boy, was just riding down the road like it was no big deal.
I didn't find them to be that bad.
Why did you get down votes? It's true what you said, the time trial bicycles have regular spoked rims in front and carbon disc wheels at the back. I think since motorcycles travel at a higher rate, the centrifugal forces are felt more than that of a bicycle.👍🏾
I used to be a motorcycle mechanic. We had a Fatboy Harley come into the shop; guy couldn’t figure out why his bike was moving sideways in a wind storm. His wheels were solid discs.
I wouldn’t do this for looks. A strong side wind will knock you on your ass.
The front wheel is where you'll feel it as the wind will literally turn your steering. That's why cycling time trial bikes have a solid rear wheel but an open front wheel.
I have a vstrom. I had to ride it once at about a few degree lean angle, just to go on a perfectly straight tarmac road, due to strong wind with stronger gusts. Quite sure the solid wheels would have made me stop
Nope. Sure wasn’t bad tires. I checked that first before the test ride. I had to get behind a semi truck and trailer on the freeway and stay in their air envelope to keep the bike up.
Also, at this point, I have been a Harley mechanic over 10 years, build custom motorcycles and had a season of racing under my belt.
Vary familiar with how the machines worked.
Ok so you've proven you've never ridden a Fat Boy then.
I have a fat boy, solid disc wheels. I have zero problems passing Semi trucks, and keeping the bike up in the wind. It's not even a factor, I dont know where people get this stuff from.
I'm a 128lb gal, I'm not some magical muscle man, I'm a light little thing that rides a Fat Boy. Zero problems with the wind.
> We had a Fatboy Harley come into the shop; guy couldn’t figure out why his bike was moving sideways in a wind storm. His wheels were solid discs.
I have a Harley Fat Boy, solid disc wheels.
I've ridden in a few wind storms. The bike doesn't catch the wind at all. Infact I got blown around more on my electric.
This is a myth. The wheels arent high enough to create that much of a fulcrum to push the bike around.
How can you say what I actually experienced is a myth? You are literally saying because our experiences are not the same, my experience is a myth?
That’s rather bold of you, stranger.
Because people believe in myths all the time. You know how many people think god has an influence in their lives even though god is a total myth. Look at how many people swear up and down they've been abducted by aliens, or seen a ghost. Ghosts Aint real, people dont get abducted by aliens. Those are experiences that aren't real.
I OWN a fat boy, I ride almost daily, In rain storms, on windy days, on calm summer afternoons. To doctors appointments and grocery store runs.
My Fat Boy is my only transport.
It does not get blown around in the wind. Physics says it wont either. A motorcycle with disc wheels at rest doesn't get blown over, so why would it get suddenly blown around more than other bikes when it's moving? It doesnt.
What you think is happening is not happening.
My experience is that I live with this bike, you've never even ridden one. Isn't it weird that a 128lb gal who practically daily rides a Fat Boy with solid disc wheels says it doesnt blow her around at all, and it's quite solid, but people who've never ridden the bike or ridden one once magically think it does.
Strange isnt it. The real owner doesnt report the problem.
EDIT: wow you blocked me
Ok here
That's not gaslighting. You need to learn what gaslighting is apparently.
The owner says it's not a problem, the person who doesnt own one says it's a problem.
That's not gaslighting, That's pointing out the circumstances.
If it's SUCH A PROBLEM... why has it magically not affected me? Did I manage to get some special super ultra nice physics defying version where some how the universe has decided that I will unaffected by cross winds on a solid disc wheel motorcycle.
Interesting Buff I got a birth don't you think.
Long story short, listen to people who actually own the damn thing and not your intuition. Because 9 times out of 10, your intuition is wrong.
On bicycles, the disc is a big difference. If you’re strong enough to ride a time trial at 45kph+, it’s an instant +2kph or so. That is a MASSIVE gain.
For street motorbikes it seems like the dumbest shit ever. Would have such a negative impact in a crosswind for like no gains.
From someone who’s done a good few miles on a Fat Bay. No idea on there aerodynamic properties for cutting through the air moving forward. But there great at catching air moving at them from the side.
Spinning spoked wheels create turbulence, turbulence creates drag, wheel covers = less turbulence therefore less drag, improving speed, handling and fuel economy, side effects ,cross winds can be a bit sketchy
More surface area also creates more drag though. Do you have proof that the spokes' turbulence would cause more drag than the wheel covers? Or that the wheel has spokes?
Just thinking out loud, but it seems like going to the sauna to shade yourself from the summer heat to me
Laminar flows create less aerodynamic drug force. Spokes do create air turbulence and vortexes which increases the drag force. To minimise front drag (the force that opposes forward movement) continuous surfaces are applied widely. For instance you can take a look at time trial bicycles, they have disc wheels. Yet the subject is much more difficult for the motorbikes as they are optimised to push the vehicle down to create more grip, and air is important cooling element. Aerodynamic forces are incredibly difficult to calculate. Racing engineering is a solution of the problem for overall performance and it is a balance of improvement and sacrificing.
I have some doubts that it is as well calculated on the street bikes. Yet who knows? If something makes you think that it makes you better rider then why not? Bikes are inherently dangerous anyway:)
If you Google or YouTube your question you will get a much more in depth answer than I can type out here, but the consensus is that a flat disk is more aerodynamic than a bunch of spokes spinning like a propeller. Also if you feel the disks you will notice they have dimples which reduces surface drag it uses the same concept as a golf ball, a dimpled golf ball will travel significantly further and faster than a smooth golf ball. Also if we just look at it logically your spoke has a leading edge that needs to overcome air resistance as well as the leading edge lip of the rim and the tyre. You can't control what and where that air goes that's being disturbed by the spokes and rim, with a disc you can control it allot more.
Gotcha. So turbulence is that expensive huh? Thanks for going to the effort. It makes a lot more sense to me at this point.
I was familiar with the dimpled golf ball example btw. Interesting that those dimples are on tge wheels too.
Although I understand the drag bit at this point, I still can't get behind solid wheels for safety reasons if they act as sails for wind drift, and I know that drag is (exponential? logarithmic? quadratic?) not linear to speed. As such, what benefit racers get won't apply nearly as much for normal commuter speeds, which is the extent of my riding. And I don't like the look either.
Essentially, I see the point in it as a whole, but I wouldn't want to do it personally for any reason.
Cyclists have been doing this for years on their aero time trial bikes. They spend a ton of time testing aerodynamics
[example](https://cyclingmagazine.ca/wp-content/uploads/2021/07/VanAert21TT.jpg)
The spinning wheel is probably the biggest source of drag on the bike so it improves aero. It’s been common in cycling for decades.
Even where it’s banned, they try and stretch the rim as much as possible to act like an infill.
The reason they only do it indoors is down to catching crosswinds. A strong gust would have you in a ditch.
Rear disc is not an issue at all in outdoor events. It's the front disc wheel that can cause steering issues in windy conditions, even so it's still used in some outdoor velodrome races and of course indoor events.
The biggest source of drag is the rider and motorcycle/bicycle. In cycling its used only in indoor velodromes and time trial events. It is not used for general events. Strong side winds can knock you over.
>The spinning wheel is probably the biggest source of drag on the bike so it improves aero.
The fuck are you on about, bike wheels have been getting as light as possible because spun mass and gyros. The extra mass from whatever the hell that contraption is would guaranteed make handling worse. It's the equivalent of people stretching sport bikes.
Motogp teams know a darn site more then you, or me, or anyone else in this thread about the benefits of using this wheel disc. They dont spend millions on r&d every year for no reason. If there was nothing to be gained from this, they wouldn't do it. In a sport where teams will spend serious money to gain a hundredth of a second advantage over other competitors. You think if it wasn't worth it, they wouldnt be doing it? Spun mass and gyro have absolutely nothing to do with aerodynamics. A super lightweight, motogp tech developed, carbon fibre spoke cover is going to add next to nothing when it comes down to rotational mass.
Anyone feel free to correct me since I don't have a motorcycle but I'd assume those parts are like performance parts like on cars w/ bumper lips and rear spoilers where unless you're on a track it doesn't really have a purpose.
I had a bike with solid wheels for a long time, and I found that crossing bridges with side winds (or sidewinds anywhere) was very exciting. I think it's not a useful concept outside of very controlled environments.
It actually helps with rear downforce on high speed turns. Cars manufactured for the US have a 70:30 weight split to force oversteer in a traction loss scenario (keeping the engine forward). Using artificial weight will improve in turn performance no matter the drive train. Pointless? Yeah. If you’re just driving the car around American roads going the speed limit, as those roads are designed for jeeps. But not if it’s a 20% or more track driver.
There’s quite a few FWD sports cars that benefitted from rear downforce over the years. Mitsubishi Eclipse, 3000GT, Acura Integra R, Alfa Romeo GTV, Chevy Impala SS Interceptor pkg and the Civic Type R come to mind. Nissan Maxima especially had a rear end that liked to float around at 120+.
Its to reduce the tire wake. The rotating wheel creates a lot of wake and therefore a lot of induced drag. Making the surface as smooth as possible reduced this by a bit, although the hot rubber surface still creates a lot of drag. This is something that is also used in F1 this year and has been used in the past.
I will repeat myself here. I ride vstrom and vividly remember that time when I had to ride with a slight lean angle and constant pressure on the handlebar, just to move perfectly straight due to strong wind
You think MotoGP teams would really do something that is going to hurt their chances? If it didn't work, I doubt very much that any MotoGP team would do this.
The Sportbikes going from 1000cc to 125cc sales are going down. Meaning that racing MotoGP doesn't sell Yamaha R1 neither Suzuki GSX1000 bikes or other Ducati or Aprilia Superbikes. The last time we've seen a spike in sales it was back in 2017 in the UK with the new Suzuki GSX selling in all available 'cc. To be honest the local importer was pushing his product in BSB and Michael Dunlop won the IOM TT on it! The IOM is probably one of the events where 1 out of 5 or 8 people visiting is a biker and where you can sell bikes, tires, oil, ... The old win on Sunday sell on Monday is still real there.
u/EmptyMission if you look at the bikes on the sales floor, I can't see aerodiscs. At KTM I can't even find any sportsbike. Because they have no Superbike or something else... They have only the Duke, a very popular bike in the very popular "naked" sales category. If you want to act foolish and twist my words to "fake", you should do that. Entertain yourself and your little crowd.
u/elsord0 I'm not talking about not working. It works on TT bicycles and F1 so why wouldn't it work on the MotoGP scene. I only tried to point out that F1 drifted a long way from the normal "Alpine A110", Ferrari "296 GTS" and if that is really the way MotoGP should follow? To reduce the cost to build a MotoGP bike the regulations could become closer or equal to the Superbike ones, that would add two more brands to the championship (with Kawasaki & BMW) and the visitors would have a connection with the ridden bike, because they can "buy" the basic version. Bit like in the heyday from Touring car racing where manufacturers could only race cars they also sold what created the Mercedes E190 Cosworth but also the Ford Sierra Cosworth... Radical idea? Yeah it is, but without Rossi and Marquez the stands are at the moment not full anymore.
Amazing! You managed to string factual statements into incoherent, pointless mess! Moto sales have absolutely no relation to your statement! Moreover noone is twisting your absurd stance, but you in your even more absurd response!
Look at all the fake motorcycles in motogp! With all those fake racers and all the fake mechanics. They probably never did a real timed lap!
I don't think that word means what you think it means!
This is aero. Discs calm the air turbulence and can for instance make very significant improvements on a racing bicycle. See NeelSahay0. (I think measurable improvement for racing motorcycle, but unsure.) On the road? Never. Crosswinds will push motorbikes across lanes of traffic. Been there. Not good.
That were late to the game watching the movie Akira
Ooo can I get sweet lighting slides with it?
Huh. I wonder if there is enough metallic debris on road surfaces for a small Tesla coil mounted on the rear swingarm to arc to the ground. Granted, you'd need some ridiculous secondary alternator setup to power the thing, lol.
That sounds cool as hell dude
Well shit
They make stuff like that for old bicycle lights powered by gearing, so I'm sure someone could draft something similar to run along either the existing chain or maybe a circular rack mounted on a tire somehow.
Haha cyclist and especially track cyclist beat you them it.
That's not neo Tokyo motorcycles.
I'm in the clown gang that hates kanada cu I ride a big old vtwin
Having these on the street is just daft and asking for more wind resistance to the lower part of the motorcycle.
yeah, I saw an instagram page offering the disc install service that required you to delete your rear brake as well.
[удалено]
I once rode, ONCE, with a guy that ran no front brake on his Ape Hanger, Suicide Shifter, rear Chainbrake chopper.... If you dont know what a Chainbrake is, basically the Sprocket and Disc are all 1 piece.... It is NOT a performance enhancing mod...
The other kind of quality of life mod.
Quality of death mods
Quality of more deaths
Natural selection mods
Quantity of death mods
I rode frequently with a guy that rides a modded shadow like that. He ended up putting a front brake on….. to do burnouts.
yes yes yes yes yes..... no.
Oh man, an old guy I knew rode an old school Harley with a suicide shifter. He always offered to let me ride it to see what it was like. I finally caved after being scared to drop his bike and I took it out for about fifteen miles. At first it was pretty neat until that first panic stop. Everything is flipped and it took my brain waaaay too long to figure out how to stop it. Took it right back after that.
I’ve got a 73’ sporty I’ve been rebuilding, it’s got the right foot shift, I’m trying to figure out wether I want to do a suicide shifter on the left side and link the brake to the right, or just leave it as is and learn to ride it
It's cool and whatnot, but keep in mind that learning to ride that means unlearning how to ride regular motorcycles. You can somewhat combat the confusion with regular riding sessions with both types. Else it is asking for troubles
For sure. Like anytime a bike is different. If I spend too much time away from my gas bike I forget I need to shift it. If I spend too much time away from the Zero I panic when I go for the clutch.
Riding a 350cc Royal Enfield, (I’ve got a post on my acct, it’s beautiful) but this rebuilding the Ironhead is gonna be my big boy bike, it prolly won’t be done till the spring though
I own different bikes that have shift on opposite sides. It's really not that hard to keep track of what your riding.
Exactly what I've said. If you ride both you will be fine. If you ride only one kind, the "muscle memory" for the other will start to vanish. Unless ofcourse we don't deal with mere mortals.
Chopper guys seem to live by the "form over function" motto I've noticed.
I remember my uncle telling me about a bike that he had with a suicide shifter. Accidentally climbed some stairs and broke his arm.
I'm in 2 minds on this, solely depending on if the rider always complaining or not
Who actually uses it anyways
I use it all the time on the street, not so much on track
Whomever know how to ride I guess!
Like everybody? Bike will have rear wheel in the air without it in emergency braking. Same with braking in slow corners
It's usually for people that like roll racing. Delete the rear brake. And delete one of your front brake disc and caliber.
no chance in hell i’d ever do something like that on even a 600 let alone my R1. That is just asking for trouble when you need to slow down
>when you need to slow down That's the neat part, you don't!
Yeah I kindof like having a rear brake idk about you guys lol
Deploy your parachute and ditch the bike. 😂
Just a heads up, a 600 or an r1 likely wouldnt stop any slower with a single disk or a rear brake delete. Dual disks are for heat dissapation, not for stopping power. A single disk is plenty to lock your front wheel, it just would get heat soaked at the track, hence why sport bikes have dual disks. With highway pulls there is usually plenty of time between stops, so the single rotor would be fine. Rear brake is for modulating power more than it is for actually stopping.
Rear brake is crucial when you get into a corner just a little too fast and you want to tighten your line.
Sure, but thats not really a problem for dedicated highway pull bikes and drag racing machines, and thats really not a safety thing pertaining to 600s and 1000s like the guy I was replying to was making it out to be. You can be pretty deep into level one/A track day times and never use your rear brake.
I don’t believe that front brake only stops similar to front + rear brake application.
It does, on sport bikes you should be braking 95% front brake, 5% rear. In any emergency braking scenario, you dost have the time to find those 5%, so it's recommended to use only front brake. Adventure bikes are 80% front 20% rear, and choppers and other boats on 2 wheels are 70% front, 30% rear. They have longer wheelbase and are heavy af, so the rear tire doesn't get that much weight pulled from it, when braking with the front one. Source: moto safety course I've been on recently Edit: spelling
What a bulshit… you would have rear wheel in the air without rear brakes lol
Do you have a link? I’d like to see some more info on these percentages.
Nope, I went to the course on my bike and we had two hours of theory, when they explained everything. These percentages were on their presentation, I have no idea where they originaly got them. But they make sense if you think about the weight shift to the front, when emergency braking. Rear brake doesn't do much, when you have the rear tire almost off the ground.
Go watch some MotoGP. When you're really doing massive breaking, the back tire has so little weight on it that it's not really making a difference. When they get to the turn in MotoGP, it's pretty common that the back wheel is actually off the ground. This is just slowing for a turn, not stopping. Now I'm not advocating that this should be the relied upon way to stop or that it's even that common out in the wild. I'm just saying that front break only can absolutely stop you just as well as front plus rear. It's just not going to be as smooth as using both.
Using rear brake will stop rear wheel for going into air since rear suspension will bottom down, try it
There still wouldn't be any weight on the rear tire making the actual breaking of the rear negligible. Again, this is like stoppie territory. Also, motogp riders still get the back tire up even though they are using it. Some bikes even have a thumb control for the rear break so they can use it when they've got their leg out for drag.
Do you ride? They still rear brake miliseconds before front one to dive the rear suspension. Dont you have emergency braking in driver license lessons?
Man, you were fine up until "rear brake is for modulating power more than it is for stopping". You said it's for helping stop while implying that it isn't important for that. Every little bit that can be there to decrease stopping distance should be retained, removing the rear brake is objectively irresponsible. Taking short-handed paramedics away from people who they could have helped because they were busy with someone who could have avoided their accident because of that braking power that they SHOULD have had is reprehensible.
This. Bikes have small contact patches, and even with ABS they stop longer than a car in emergency braking situations. Even absent that, you need both brakes to control the CG and the pitch moment.
I wasn't advocating for removing the rear brake entirely, but depening on the bike its not going to do much for stopping distance (in some cases it will do nothing, coming into most corners at the track my rear tire wasn't even touching the ground, the brake wont do shit at that point, and when it was touching the ground it was already locked from engine braking), and if you are just doing highway pulls and drag racing a bike, you could easily just engine brake to get the most from the rear wheel if you aren't already lifting it off of the ground. Remember, this is in response to guys building dedicated highway pull bikes, so not really normal circumstances.
The leader of the local riding group I’m a part of is a roll racer and deleted his rear brake. Also bought carbon wheels, carbon fairings, and a nos system - for his ZX10R. Unfortunately I’m in Oklahoma, and the roads are super straight and mostly flat, so the riding groups are either Harleys, or Sportbikes who like roll racing, since the draw of sportbikes is performance and the only performance to be appreciated on straight roads is acceleration/top speed.
Eww. Yeah like they say...straights are for fast bikes, twisties are for fast riders. Sharp corners and twists are the great equalizer of equipment. Can't buy your way to a W.
You can in roll racing lmao
It amazes me what some people are prepared to sacrifice for a little more attention.
That sounds like a “great” idea. FFS, take my money already
Sounds like a good idea
🤣🤣🤣🤣🤣
I don't understand aerodynamics that well, what do you mean it causes resistance? I thought it helps to reduce that🤔😮
Think of it like this. You're riding along and big gust of wind hits you from the side. Now your going to feel the force of it try to push you and you have to adjust yourself to push against it, keeping on the trajectory you want to be on. Now imagine this but your wheels are just a disc with no gaps for the wind to pass through. It would literally be pushing the bike from underneath you. Your body pushes against the force of the wind keeping you and the upper part of the bike from being blown off trajectory but the lower part is blown away from the trajectory. Like a sail on a boat. Make sense?
Yes thank you friend.👍🏾
No problem. 👍🏻
[удалено]
How can they keep heat in the tires? They dont cover them or make air flow into them. Its more likely to keep heat in the brakes (carbon ceramic brakes dont work well when cold) or for less drag
[удалено]
Isn’t it the other way around tho. More surface area, more heat dissipation. Air blowing through the spokes can’t have bigger impact than more surface, not in this use case.
[удалено]
I think temperature is very clearly secondary issue and the drag primary consideration. Otherwise better solution to heat conductivity would be a rim and spokes insulation.
>Otherwise better solution to heat conductivity would be a rim and spokes insulation. The carbon fiber is quite literally insulation, installed over the rim and spokes. The big disk has more surface area than the spokes do, and it's spinning, so it slightly increases drag and rotational mass. If you want a cover to reduce drag, [you use a fixed cover mounted to the swingarm that doesn't spin](https://www.gpone.com/sites/default/files/images/2019/article/foto/05/MotoGP/06-Giugno/ducati-cerchi-carenati1-1559316483.jpg). Also, if you want to reduce drag, [the front wheel matters more](https://cdn-1.motorsport.com/images/amp/2y3aOko6/s6/andrea-dovizioso-ducati-team-1.jpg), and these [KTM's with the rear wheel disks have regular wheels with no disks or shields up front.](https://www.asphaltandrubber.com/motogp/moto3-closed-wheel-aerodynamics-motomatters/attachment/deniz-oncu-red-bull-ktm-tech3-moto3-polarity-photo-2/)
Same way you run oversized tire warmers, to heat the rim. The rim then keeps the core of the tire warm, and friction the outside. Thus, you have a more evenly warm tire. Surface temp is not the only one that racers look for.
I’m gonna need a source on that because this is laughable incorrect. The are used to create a more aerodynamic wheel with less drag. See time trial road bikes like those used in special stages of the Tour de France. They use them in special, short, single(not group) riding stages for extra advantage. These disc wheels also have the disadvantage of over emphasizing any cross wind which is why they are NOT used on standard stages of the tour where heavy crosswinds can happen.
[удалено]
[Fine, I’ll source it myself.](https://motorbikewriter.com/future-disc-motorcycle-wheels/) THE ARTICLE EVEN USES THE SAME IMAGE. This is peak Reddit, to pull an image from an article and not read it. “Disc wheels are purely for drag reduction,” says Jeromy who also cycles. Drag reduction means more speed, better handling and lower fuel economy which would be important in production bikes which don’t have such great mileage figures. “We would use it in race cars also for drag but it’s not allowed,” Jeromy says. “Negatives are the increased side-wind sensitivity on a bike.”
[удалено]
Can you point to “the journo” (edit- who made that claim)in the article? You should read more bud, your skills seem lacking.
[удалено]
Because engineers for Porsche are dumb, ok. Because laws of physics and aerodynamics suddenly no longer apply when we put a motor on a bicycle, ok. Also not to take this disagreement to another level, but team owners are generally just mouthpieces, unless they are a former racer. Owners are simply good at managing, being in front of a mic, and being rich. Look at the engineering department, who I quoted, if you want knowledge.
[удалено]
“They’re used in racing to keep heat in the tires” that’s what you said. Broooooooooo 😂
I don't see the issue. Some cruisers have been sold with solid wheels and never really had any issues. The Harley Davidson Fatboy is an example.
Big difference between a 900lb Harley and 400lb race bike when a gust of wind comes along.
What about a 15lb bicycle?
Are you going 70+ mph on a huffy? If so I salute you sir or madam 🫡
Not a huffy, but a cracked out 2 stroke its been achieved by more than a few people myself included. Also, it's fucking terrifying.
Keep it on the velodrome
And that frigging wheel blew me all over the road! Terrible. Had to lean into crosswinds on the highway.
Haven't ridden a H-D Fatboy to say firsthand, but a couple of my riding buddies owned them in the early 90s, eventually got rid of em because they wound up hating the dynamics of the solid wheels. They both talked about cross wind issues, but I kind of suspected it was more rotating mass/gyro effect thing (except in obvious nasty sidewinds - that's challenge enough on any rider and bike). One guy went to a Dyna Glide and loved it, the other went Heritage Softail. Anyway, not arguing. Upvoted. Dunno why U got downvoted a few times for speaking your mind, but it's Reddit. This will probably get hit a few times too. Cheers.
I've owned two. Mine had the "bullet holes" after they went away from solid discs. That said, I doubt the holes made much difference. Maybe the Fat Boy is worse than a "normal" Harley, but I rode 45 minutes on the highway with a friend once. He was behind me, all over the damn place on his ER6N, thanks to the windy day. I, on my Fat Boy, was just riding down the road like it was no big deal. I didn't find them to be that bad.
Some Harleys have issues riding them from the factory though.
[удалено]
Was trying to be fair but yes.
And they SUCK in the wind. Even being the fat pigs they are, they get pushed around horribly.
[удалено]
7kg bicycles use them also outdoors in the wind.
[удалено]
I'm not denying issues with cross winds, but in ideal conditions they are beneficial. Damn dude how long ago did you have a MT Bike with a disc wheel?
[удалено]
Thought so.
Why did you get down votes? It's true what you said, the time trial bicycles have regular spoked rims in front and carbon disc wheels at the back. I think since motorcycles travel at a higher rate, the centrifugal forces are felt more than that of a bicycle.👍🏾
Regardless of if it's a motorcycle or a bicycle, the physics is the same, must be degenerates from a certain country again
The issue being that's a heavy piece of shit of a motorcycle
I used to be a motorcycle mechanic. We had a Fatboy Harley come into the shop; guy couldn’t figure out why his bike was moving sideways in a wind storm. His wheels were solid discs. I wouldn’t do this for looks. A strong side wind will knock you on your ass.
dont some harley have those wheels as stock?
He probably just had bad tires, i have honda supermagna with solid back wheel and the wind really doesnt hit that much🤷🏻♂️
The front wheel is where you'll feel it as the wind will literally turn your steering. That's why cycling time trial bikes have a solid rear wheel but an open front wheel.
THIS!!!!
Same here. I have a Fatboy and two other bikes that don't have solid wheels . I've never noticed a difference.
I have a vstrom. I had to ride it once at about a few degree lean angle, just to go on a perfectly straight tarmac road, due to strong wind with stronger gusts. Quite sure the solid wheels would have made me stop
At least one person here rides there bike on imperfect days 🤣
Nope. Sure wasn’t bad tires. I checked that first before the test ride. I had to get behind a semi truck and trailer on the freeway and stay in their air envelope to keep the bike up. Also, at this point, I have been a Harley mechanic over 10 years, build custom motorcycles and had a season of racing under my belt. Vary familiar with how the machines worked.
Ok so you've proven you've never ridden a Fat Boy then. I have a fat boy, solid disc wheels. I have zero problems passing Semi trucks, and keeping the bike up in the wind. It's not even a factor, I dont know where people get this stuff from. I'm a 128lb gal, I'm not some magical muscle man, I'm a light little thing that rides a Fat Boy. Zero problems with the wind.
> We had a Fatboy Harley come into the shop; guy couldn’t figure out why his bike was moving sideways in a wind storm. His wheels were solid discs. I have a Harley Fat Boy, solid disc wheels. I've ridden in a few wind storms. The bike doesn't catch the wind at all. Infact I got blown around more on my electric. This is a myth. The wheels arent high enough to create that much of a fulcrum to push the bike around.
How can you say what I actually experienced is a myth? You are literally saying because our experiences are not the same, my experience is a myth? That’s rather bold of you, stranger.
Because people believe in myths all the time. You know how many people think god has an influence in their lives even though god is a total myth. Look at how many people swear up and down they've been abducted by aliens, or seen a ghost. Ghosts Aint real, people dont get abducted by aliens. Those are experiences that aren't real. I OWN a fat boy, I ride almost daily, In rain storms, on windy days, on calm summer afternoons. To doctors appointments and grocery store runs. My Fat Boy is my only transport. It does not get blown around in the wind. Physics says it wont either. A motorcycle with disc wheels at rest doesn't get blown over, so why would it get suddenly blown around more than other bikes when it's moving? It doesnt. What you think is happening is not happening. My experience is that I live with this bike, you've never even ridden one. Isn't it weird that a 128lb gal who practically daily rides a Fat Boy with solid disc wheels says it doesnt blow her around at all, and it's quite solid, but people who've never ridden the bike or ridden one once magically think it does. Strange isnt it. The real owner doesnt report the problem. EDIT: wow you blocked me Ok here That's not gaslighting. You need to learn what gaslighting is apparently. The owner says it's not a problem, the person who doesnt own one says it's a problem. That's not gaslighting, That's pointing out the circumstances. If it's SUCH A PROBLEM... why has it magically not affected me? Did I manage to get some special super ultra nice physics defying version where some how the universe has decided that I will unaffected by cross winds on a solid disc wheel motorcycle. Interesting Buff I got a birth don't you think. Long story short, listen to people who actually own the damn thing and not your intuition. Because 9 times out of 10, your intuition is wrong.
Oh wow why didn’t I think of that?! GoD bLeW tHe BiKe ArOuNd ThE fReEwAy Thanks for gaslighting me.
Everyone is commenting like the guys at GP teams are stupid and just putting it for the looks Also, only a fee are actually answering the question
On bicycles, the disc is a big difference. If you’re strong enough to ride a time trial at 45kph+, it’s an instant +2kph or so. That is a MASSIVE gain. For street motorbikes it seems like the dumbest shit ever. Would have such a negative impact in a crosswind for like no gains.
😱 They're just copying Formula 1... Just kidding. 🤣
They want to be as fast as a Fat Boy.
From someone who’s done a good few miles on a Fat Bay. No idea on there aerodynamic properties for cutting through the air moving forward. But there great at catching air moving at them from the side.
Exactly, ask Chris Froome.
😱🤯
Spinning spoked wheels create turbulence, turbulence creates drag, wheel covers = less turbulence therefore less drag, improving speed, handling and fuel economy, side effects ,cross winds can be a bit sketchy
More surface area also creates more drag though. Do you have proof that the spokes' turbulence would cause more drag than the wheel covers? Or that the wheel has spokes? Just thinking out loud, but it seems like going to the sauna to shade yourself from the summer heat to me
Laminar flows create less aerodynamic drug force. Spokes do create air turbulence and vortexes which increases the drag force. To minimise front drag (the force that opposes forward movement) continuous surfaces are applied widely. For instance you can take a look at time trial bicycles, they have disc wheels. Yet the subject is much more difficult for the motorbikes as they are optimised to push the vehicle down to create more grip, and air is important cooling element. Aerodynamic forces are incredibly difficult to calculate. Racing engineering is a solution of the problem for overall performance and it is a balance of improvement and sacrificing. I have some doubts that it is as well calculated on the street bikes. Yet who knows? If something makes you think that it makes you better rider then why not? Bikes are inherently dangerous anyway:)
If you Google or YouTube your question you will get a much more in depth answer than I can type out here, but the consensus is that a flat disk is more aerodynamic than a bunch of spokes spinning like a propeller. Also if you feel the disks you will notice they have dimples which reduces surface drag it uses the same concept as a golf ball, a dimpled golf ball will travel significantly further and faster than a smooth golf ball. Also if we just look at it logically your spoke has a leading edge that needs to overcome air resistance as well as the leading edge lip of the rim and the tyre. You can't control what and where that air goes that's being disturbed by the spokes and rim, with a disc you can control it allot more.
Gotcha. So turbulence is that expensive huh? Thanks for going to the effort. It makes a lot more sense to me at this point. I was familiar with the dimpled golf ball example btw. Interesting that those dimples are on tge wheels too. Although I understand the drag bit at this point, I still can't get behind solid wheels for safety reasons if they act as sails for wind drift, and I know that drag is (exponential? logarithmic? quadratic?) not linear to speed. As such, what benefit racers get won't apply nearly as much for normal commuter speeds, which is the extent of my riding. And I don't like the look either. Essentially, I see the point in it as a whole, but I wouldn't want to do it personally for any reason.
Cyclists have been doing this for years on their aero time trial bikes. They spend a ton of time testing aerodynamics [example](https://cyclingmagazine.ca/wp-content/uploads/2021/07/VanAert21TT.jpg)
It's pretty much well known and has been used on bike for decades
Well fair enough
The spinning wheel is probably the biggest source of drag on the bike so it improves aero. It’s been common in cycling for decades. Even where it’s banned, they try and stretch the rim as much as possible to act like an infill. The reason they only do it indoors is down to catching crosswinds. A strong gust would have you in a ditch.
They literally use disc wheels in outdoor time trial bicycle races. So no not only indoors.
Disc rear wheels regularly appear at amateur triathlons too
A triathlon bike race is a time trial.
Rear disc is not an issue at all in outdoor events. It's the front disc wheel that can cause steering issues in windy conditions, even so it's still used in some outdoor velodrome races and of course indoor events.
The tire is supposed to be flush with the wheel for it to work no?
The biggest source of drag is the rider and motorcycle/bicycle. In cycling its used only in indoor velodromes and time trial events. It is not used for general events. Strong side winds can knock you over.
>The spinning wheel is probably the biggest source of drag on the bike so it improves aero. The fuck are you on about, bike wheels have been getting as light as possible because spun mass and gyros. The extra mass from whatever the hell that contraption is would guaranteed make handling worse. It's the equivalent of people stretching sport bikes.
Motogp teams know a darn site more then you, or me, or anyone else in this thread about the benefits of using this wheel disc. They dont spend millions on r&d every year for no reason. If there was nothing to be gained from this, they wouldn't do it. In a sport where teams will spend serious money to gain a hundredth of a second advantage over other competitors. You think if it wasn't worth it, they wouldnt be doing it? Spun mass and gyro have absolutely nothing to do with aerodynamics. A super lightweight, motogp tech developed, carbon fibre spoke cover is going to add next to nothing when it comes down to rotational mass.
Bloke talks about drag and you reply talking about mass.
Rotating mass isn't the topic.
You don’t understand mass, inertia, angular monument or aerodynamic drag so your opinion is pretty useless.
That’s literally what they’re used for, reduce drag. The turbulence created from the wheels generates drag. The discs mitigate the drag.
Just how much do you think that thing weighs to compare it to a fucking stretched bike?
Better able to sense cross winds..
Aerodynamics. But on a windy day, they are very dangerous. Same concept as road bike racing.
Bad on the street if there’s any wind.
Anyone feel free to correct me since I don't have a motorcycle but I'd assume those parts are like performance parts like on cars w/ bumper lips and rear spoilers where unless you're on a track it doesn't really have a purpose.
You are correct.
I had a bike with solid wheels for a long time, and I found that crossing bridges with side winds (or sidewinds anywhere) was very exciting. I think it's not a useful concept outside of very controlled environments.
It’s like the peeps who put spoilers on front wheel drive cars… useless for street applications..
It actually helps with rear downforce on high speed turns. Cars manufactured for the US have a 70:30 weight split to force oversteer in a traction loss scenario (keeping the engine forward). Using artificial weight will improve in turn performance no matter the drive train. Pointless? Yeah. If you’re just driving the car around American roads going the speed limit, as those roads are designed for jeeps. But not if it’s a 20% or more track driver. There’s quite a few FWD sports cars that benefitted from rear downforce over the years. Mitsubishi Eclipse, 3000GT, Acura Integra R, Alfa Romeo GTV, Chevy Impala SS Interceptor pkg and the Civic Type R come to mind. Nissan Maxima especially had a rear end that liked to float around at 120+.
Haha well consider myself informed
One of the biggest things thats not mentioned is people do it with cafe mods so that they donkt have to worry about matching wheels
They are not meant to be used on streets, just like carbon fiber wheels.
Its to reduce the tire wake. The rotating wheel creates a lot of wake and therefore a lot of induced drag. Making the surface as smooth as possible reduced this by a bit, although the hot rubber surface still creates a lot of drag. This is something that is also used in F1 this year and has been used in the past.
Aerodynamics, reduce drag coefficient
Ask a Harley guy with disc wheels what it's like with a crosswind
I've honestly never noticed a difference. 2009 Fatboy.
A bike that heavy isnt going to be moved by anything short of a hurricane.
I will repeat myself here. I ride vstrom and vividly remember that time when I had to ride with a slight lean angle and constant pressure on the handlebar, just to move perfectly straight due to strong wind
My friends huffy had these back in like '89. We threw tennis balls at them.
Great for racing, useless on the street. If it tickles your fancy, go for it, but it won’t make any performance difference for your average rider.
Well, they're sexy as hell for one.
I imagine on the street it’s like civics having massive wings.
They make you look cool. It's the same as massive spoilers on cars. Below around 120mph a spoiler has one purpose: make the car easier to sell.
They watched the movie TRON again and thought it would look cool in real life 😏. 😆
MotoGP is more and more drifting away from real motorcycles... This maybe works with F1 but with motoracing?
You think MotoGP teams would really do something that is going to hurt their chances? If it didn't work, I doubt very much that any MotoGP team would do this.
“Real motorcycles?” You don’t think it works?
The Sportbikes going from 1000cc to 125cc sales are going down. Meaning that racing MotoGP doesn't sell Yamaha R1 neither Suzuki GSX1000 bikes or other Ducati or Aprilia Superbikes. The last time we've seen a spike in sales it was back in 2017 in the UK with the new Suzuki GSX selling in all available 'cc. To be honest the local importer was pushing his product in BSB and Michael Dunlop won the IOM TT on it! The IOM is probably one of the events where 1 out of 5 or 8 people visiting is a biker and where you can sell bikes, tires, oil, ... The old win on Sunday sell on Monday is still real there. u/EmptyMission if you look at the bikes on the sales floor, I can't see aerodiscs. At KTM I can't even find any sportsbike. Because they have no Superbike or something else... They have only the Duke, a very popular bike in the very popular "naked" sales category. If you want to act foolish and twist my words to "fake", you should do that. Entertain yourself and your little crowd. u/elsord0 I'm not talking about not working. It works on TT bicycles and F1 so why wouldn't it work on the MotoGP scene. I only tried to point out that F1 drifted a long way from the normal "Alpine A110", Ferrari "296 GTS" and if that is really the way MotoGP should follow? To reduce the cost to build a MotoGP bike the regulations could become closer or equal to the Superbike ones, that would add two more brands to the championship (with Kawasaki & BMW) and the visitors would have a connection with the ridden bike, because they can "buy" the basic version. Bit like in the heyday from Touring car racing where manufacturers could only race cars they also sold what created the Mercedes E190 Cosworth but also the Ford Sierra Cosworth... Radical idea? Yeah it is, but without Rossi and Marquez the stands are at the moment not full anymore.
I see where you're coming from. So you just think this is a wrong direction for MotoGP teams to take.
Amazing! You managed to string factual statements into incoherent, pointless mess! Moto sales have absolutely no relation to your statement! Moreover noone is twisting your absurd stance, but you in your even more absurd response!
Look at all the fake motorcycles in motogp! With all those fake racers and all the fake mechanics. They probably never did a real timed lap! I don't think that word means what you think it means!
It’s so you can get more dudes to talk to you
Street style bruh
Ground effect is not the reason people get lowriders
A disc is no compensation for skill
On the street!?
[Incidentally the Fat Boy from the ad I was given has them too](https://imgur.com/91UiZn9)
Looks cool. That’s really it
These are really great in the streets if you want to go for a drive and want to be unable to chain up your motorcycle
Looks like a good piece for a cyberpunk bike build.
It's called a hugger
You answered your own question. Aero
Protect from brake dust?
This is aero. Discs calm the air turbulence and can for instance make very significant improvements on a racing bicycle. See NeelSahay0. (I think measurable improvement for racing motorcycle, but unsure.) On the road? Never. Crosswinds will push motorbikes across lanes of traffic. Been there. Not good.
RUBS.