Chain vs belt vs shaft

[NanoBear]

Just out of curiosity really...

My dad's cruiser is shaft drive, the bike i want (also cruiser) is belt drive, while to the best of my knowledge, sports bikes are all chain. Is there a mechanical/technical reason why sports bikes are all chain, or are there some that aren't? Only thing I can think of is a power/strength issue, but surely a 2.3L rocket III(shaft) or a 2.0L vulcan 2000 (belt) have more power than than the small sports bikes. The way I understand it, the chains require somewhat more maintenance than the other systems.

[Captain Starfish]

Dunno about belts.

There's a reason all the race bikes use chain, it's because chain is the most efficient power transfer mechanism from engine to wheel.

But, chains get full of rubbish and need lubrication and maintenance. So from that point of view, the shafts are great.

Having had both, I'd not really think about it much. If you have enough power through a shaft drive, you score - much lower maintenance (although the final drive, or equivalent of a diff, tends to wear out eventually and they're a bit more expensive than a chain and sprockets).

If you have a chain, the maintenance isn't much - lube it with proper sticky shit every two or three tank fills. Occasionally try to pull the chain away from the back of the wheel sprocket - if it lifts completely off the teeth, time to replace.

Not too much either way, IMO.

[thro]

Shaft = heavy
I think a belt would be more prone to slipping.

Chain = dirty, cheap, but does the job if you maintain it.


edit:
22,000km on my chain so far. its still good.

If you spend 5 minutes every 2 weeks lubing it and clean it every now and again, its no big deal.

[MADOGA]

If your looking at cruisers belts are probably better than shaft, with a shaft you can get shaft lash, some bikes get this worse than others, beyond that probably not much difference between the 2 other than visual.
Belts are great keeps the bike a lot cleaner,wont slip unless its faulty or the engines has had some serious work done to it, and look nicer from a biased point of view.

[BigTim]

Occasionally try to pull the chain away from the back of the wheel sprocket - if it lifts completely off the teeth, time to replace.

Or you could just tighten it?

[D'Artagnan]

Belts would be the best compromise IMHO. Shafts also (though they're getting much better) have the torque issue. This is because the mass of the spinning shaft in one direction will mean the bike will resist tipping one way, but assist the other. But really, nowadays there's not much there. Although it may explain why FJSteve likes only going left!

Belts are lower maintenance than chains. Probably the reason BMW chose belts for their F series.

Chains need to be lubricated often. Failure to do this will mean new chain and sprockets, and at worst, you can damage bearings from what I've been told.

Check here

D'Art

[Arwon]

Shaft drive would also have power loses..


Fj Steve prefers turning left because thats the side he falls off the bike, when he is tired

[Ferris]

Belt drive here: They snap under duress, like wheelies. No maintenance, no lubrication, no tightening needed. They don't slip. (they're not like a fan belt, they're toothed, and have sprockets to match.) Also, super quiet.

But yeah, only downside, they can snap. It's rare, and I've only ever snapped one, but that's 1 more than any chain.

[Hostilemonk]

^^WTS
Shaft - less efficient than others, less power to rear wheel, great for long distance as no chain oiling or maintenance, no adjustment, clean, modern machines don't have that much jacking from the shaft. cheap to run (nothing to replace eg. sprockets). I prefer shaft on a road bike

Belt - more efficient than shaft, no maintenance, can be problematical on hi performance machines, as belt is comparatively wide needs wider sprockets so not good on sports machines, can snap - until new materials become available will be limited in application IMO. BUT can be a total pain to replace as there is no joining link - have to take the bike apart on some models e.g. some Harleys - how would you fit a belt to modern sports bike unless it had single sided swing arm?

Chain - most efficient, needs constant oiling (use an oiler like scott for long distance), needs regular adjustment, costly, dirty, great for short rides and racing, not worth it for long distance riding IMO.

For road riding, unless you want the last .005 HP and a shaft is available in the class you want, then shaft is better IMO.

look at the 'top 5 or 6' sport tourers = shaft drive.

[D'Artagnan]

look at the 'top 5 or 6' sport tourers = shaft drive.

Look at the top selling Sports Tourer of recent years and it has a chain, but point taken :p


All good points BTW.

[SYLO]

Sportsbike with a belt drive ....... come look at my Buell XBSTT

[Captain Starfish]

Sportsbike with a belt drive ....... come look at my Buell XBSTT

Oh. I geddit. Hahahahahaha

[Ferris]

Hey, fuck you Starfish.

[rossguzzi]

Chains popular for sportsbikes because for racing its easy to change ratios. Very difficult for shaft bikes.
Belts ok, but watch you dont get a stone inbetween belt and pully!