How come belts aren't used more for final drives?

[DELETE-PLEASE]

I don't know much, if anything at all about bikes. I'm trying to learn as I go. But I'm wondering why belts aren't used more often in the sport-touring world. I know they are used in cruisers, and I know the BMW F800ST uses a belt, but it seems to be very low maintenance, easy/cheap to replace, and it still makes the bike go, right? Is it due to it not being the best choice for a high HP or high torque situation (would the belt slip?) I'm just curious. Cause it seems to me it requires less maintenance than a chain, but is easier replaced/cheaper to replace than a shaft gone bad. Just wondering if there's some reason in the design why it wouldn't work.

Alexi

 

[ionbeam]

More power requires a wider, stronger belt. Width clearance adds up to a wider final drive system. Other than that, belts are a good solution.

 

[C&C]

Chains: best transfer of power, to friction loss

Belts: also very good transfer of power but they get wide as the h/p increases

Reargear: greatest loss to parasitic drag but strong and low maintenance system

 

[charismaticmegafauna]

<snip>I'm wondering why belts aren't used more often in the sport-touring world. ...Just wondering if there's some reason in the design why it wouldn't work.

I don't think there's any (good) reason why belts aren't used. Some of the very first motorcycles were belt-driven and, in the last couple decades, belts have gotten really good.

The answers, if any, can probably be found in a textbook for mechanical engineering 101?

I tend to think it's a matter of fashion more than anything.

Open drive chains can get real inefficient real fast when exposed to the elements -- they'll stay like new a lot longer when enclosed and running in lube (nobody seems to like that...?).

Wide belts still are probably not wider than shaft-drive apparatus?

Longevity of shaft drive isn't an issue (one notable marque, excepted... ).

I tend to think it's a matter of fashion more than anything.

 

[DELETE-PLEASE]

Yeah. I don't know much about bikes. But if it IS mostly for fashion, or tradition, or whatever it just stinks that it's come to that. Of course, I'm a substance-over-style kinda guy. It's my woman that makes sure I have some sort of style (she's starting me off easy . . . buying me all new socks so I have matching sets instead of how I do it . . . white sock to white sock, black to black/darkblue).

Just seems like the way a belt/chain works would be MUCH more efficient than trying to mesh gears and whatnot. And I've always heard a belt is MUCH less upkeep than a chain (I for a BRIEF time had a honda 919 and was cautioned to oil the chain once a week or buy some sort of oiler). So I would think bikes that are meant to go long distances, trouble free, would gravitate towards the efficient, still easy use of a belt. If that is indeed the characteristics of a belt.

Alexi

 

[rockmurf]

First off chains and sprockets are much more reliable than those of decades past. They also offer more power to the rear than shaft or belt. Previously mentioned the width of the belt to handle higher power would not work on most bikes. Also the belt does not offer the flexibility of the chain. Meaning you can swap out sprockets to increase/decrease low/upper end. Once you get used to a chain you find it is not the pain in the ass that you originally thought.

 

[Dusty]

More Hp = Wider Belt???

Not always...

My 2001 Road Star had belt drive. A few years later Yamaha upgraded the engine, which resulted in larger displacement and more Hp.

The belt for the newer more powerful engine was considerably narower. Perhaps yamaha discovered that the original belt was overkill?? Also, I would think that TORQUE would have more of an impact on belt size than HORSEPOWER. :blink:

 

[Ford68xl]

Check out the Boss Hoss belt. Although wider than the RoadStar or HD belts, it is not as wide as one would think you would need for a 385 HP small block Chevy engine. From what I have read Boss Hoss reports few, if any, belt failures. My Yamaha Warrior had a belt and I only checked it periodically for nicks and small stone blemishes. Never had a problem.

 

[Aasland]

I've put many long days on chain-driven bikes, and keeping them lubed isn't a problem. Takes less than two minutes to pop it up on the center stand and spray the chain at the end of each day. Then, once or twice a year (15k-20k) spend an hour and $200 to install new chain/sprockets. It's not a big deal.

Once a upon a time I had a Scott-oiler. Due to changing temperatures during the day (on 500-miles days we're bound to get that) it wasn't dripping enough or it dumped the whole reservoir out, so much it contaminated the brakes. That thing didn't last long .. back to centerstand+spray.

I wish the FJR had a belt drive, especially if that would eliminate (or even reduce) the gear lash.

 

[reecebike]

I dont know what the hell yall are talking about nothing beats the drive shaft!! you dont have to tighten them,oil, replace them. Hell get real !!!