Gear Drive better than Belt Drive?

[Constant Mesh]

Is a gear drive preferable to a belt drive?

The Star Roadliner uses a belt drive and it has 117 lb-ft of torque at the rear wheel. So, the FJR engine is not too stout for a belt drive.

Is a belt drive inappropiate for a machine capable of going 150 mph?

A belt drive system looks to be lighter than a gear drive. It also doesn't have two 90 degree gearsets in the drive system -- so it's probably more efficient.

What are the disadvantages of a belt drive?

 

[GunMD]

What are the disadvantages of a belt drive?

That would give my bike something in common w/ HD's.

 

[MikeYork5]

Whats your point? FJR is driveshaft and then there are belt drives, - tomato - tomaato, potato - paatato (well you get the idea). Disadvantages - they can break and they wear.

 

[RadioHowie]

What are the disadvantages of a belt drive?

That would give my bike something in common w/ HD's.

Not unlike its poseur, Viper-driving owner???

Whats your point? FJR is driveshaft and then there are belt drives, - tomato - tomaato, potato - paatato (well you get the idea). Disadvantages - they can break and they wear.

Unlike those unbreakable, never-wear-out driveshafts, u-joints, ring and pinion gears???

 

[GunMD]

Not unlike its poseur, Viper-driving owner???

I don't recall seeing any HD's being trailered by a Viper...

 

[MikeYork5]

Unlike those unbreakable, never-wear-out driveshafts, u-joints, ring and pinion gears???

Oh so true - I guess - but

I've had a few BMW's with nary an issue - anybody whos ever had a problem with a shaft drive raise ur hand -

For that matter - who ever has had a problem with a belt raise ur hand -

 

[2tsnon]

For that matter - who ever has had a problem with a belt raise ur hand -

Well I was riding with a buddy with a Harley. New bike probably less than 2000 miles. Just off the second ferry boat going north in British Columbia his belt snapped. The speculation was a rock got between the belt and the rear cog. The belt have no give, the rock didn't crush, so the belt snapped. I imagine its a 1 in a million but it happened. 8hrs later the Harley tow got there. BTW that's when I learned to love Canadians. I don't think one passed by without offering to help. :thumbsupsmileyanim:

 

[RadioHowie]

Not unlike its poseur, Viper-driving owner???

I don't recall seeing any HD's being trailered by a Viper...

No, but I've seen Vipers put on their trailers by Harleys.

 

[SouthernCruizer]

Chain drive - most efficient, most maintenance

Belt drive - not quite as efficient, not much maintenance

Gear drive - least efficient, almost maintenance free

 

[RadioHowie]

Chain drive - most efficient, most maintenanceBelt drive - not quite as efficient, not much maintenance

Gear drive - least efficient, almost maintenance free

Chain drive most efficient? You sure? And why would a belt, which has no moving parts, be less efficient than a chain, which has what...216 moving parts for a 108 link chain? And all those moving parts, the rollers, lose efficiency the second they do their jobs, i.e., roll. Since there is no "perfect" lubricant, those rollers are never rolling at 100% efficiency and even freshly lubed, they lose efficiency with every pass over the sprocket until they need lubing again, which only restores their efficiency to a fraction of their "new" efficiency level, and degrades quickly 'til they need another lubing again.

And besides the lack of moving parts with the belt, which essential needs no lubrication, or can be considered "self lubricating", isn't the stress friction, basically the contact point between the drive medium and the drive and driven pulleys, spread out more with a wide belt than a narrow chain? I'd love someone to calculate the PSI of a 1/8" wide chain roller at point of contact with the driven sprocket and compare that with the contact PSI of a 1 inch wide belt contacting the driven pulley of an equally weighted and powered motorcycle under similar acceleration.

Gear drive - least efficient. Yep. Almost maintenance free - man, you need to define "almost". If almost means maybe once in a million years, I'll give you "almost maintenance free". Otherwise, it still beats hell out of a chain, but doesn't really surpass a belt.

Finally, so as to not beat this to death with opinions, which of the three would you prefer replacing when/if they go tits up? A chain, along with its countershaft and rear wheel sprockets, a belt with same, or a driveshaft, u-joint, pumpkin, ring and pinion? Factor in cost and labor.

I figure a belt wins. Costs pretty much equal to chain, but no special tools needed to install.

Oh, one final + for a belt over both chain and shaft. Much, MUCH quieter. Never heard a belt grind like a chain or whine like a shaftie.

 

[C&C]

The typical drawback for belts were that they couldn't handle the power of some of the high hp bikes. They could handle it, but it required a wider belt, which pretty soon meant too wide a belt. The newer belts are alot better but the chain is the most efficient; that's why the racers use chains; strong and the most compact.

 

[Thug]

FFS! Shaft drive good...Belt drive rubbish (poor man's chain)

Here endith the lesson...

 

[GunMD]

Oh crap...this thread is going nowhere and fast.

Hey fellas, what kind of chain lube is best for my XQ900 Super-Duper-Racer-Bike? :blink:

 

[odot]

Naw, this thread was a hit. I liked the part where they made fun of your car.

 

[jestal]

There you go again. Hoping for the "best" answer when there is none. Depends on the application totally. For ease of use the shaft wins hands down. Chains provide minimal packaging space, lightness, strength and easy flexibility in gearing changes. Belts require less maintenance then chains but are not as strong. Both chains and belts are MUCH cheaper to incorporate into the basic design of the motorcycle and MUCH cheaper in terms of manufacturing and tooling costs.

Chains are the most efficient. Very little power lost due to friction in a roller chain. The only real thing causing wear in a roller chain is debris and crap from the road. An enclosed roller chain will run forever given proper design and loading. Look at roller chain cam drives in OHC and DOHC car and bike engines. They are lifetime parts that show little or no wear in hundreds of thousands of miles.

An elastomer drive belt will always be shock and power limited due to the adhesion of the rubber cogs to the plys that give it its basic strength. They can be very strong but not as strong as a chain for a given packaging dimension....i.e...a belt wide enough to handle the power of a superbike would have to be very wide. Belts eat a fair amount of power due to the compressibility of the cogs in the sheaves. The resiliency of the rubber cogs is one of the desireable effects of a belt drive for damping vibrations but that does add friction that the roller chain does not have.

I'll take a shaft anyday for a bike like the FJR. Very strong, totally enclosed and virtually maintenance free. The shaft drive on my XS1000 Yamaha has 110,000 miles on it with nothing but occasional lube changes and spline lubrication. Same OEM u-joint and never and ounce of problem. Just forget about it forever. When is the last time you changed the final drive oil in your CAR for instance. Think about this when getting anal about changing the final drive oil in the FJR.

Totally enclosed means it is impervious to injesting rocks or stones or water or sand or mud. Sand and grit can wear the sheaves on a belt drive and obiously take a toll on chains.

The main disadvantages of a shaft are the relatively fixed final drive ratio. Much much harder to change the final drive ratio in a shaft system than with a chain or belt, especially with a bike setup where the final drive is designed and packaged around a specific gear set, not like an automotive hypoid gearset that can encompass a wide range of ratios in a single housing. This is the most obvious reason that shafts are not on drag bikes and road race bikes. No tuning capability. And there is the matter of torque reaction of the ring and pinion as the pinion trys to climb the ring gear during acceleration and vice versa.

The machining and tooling costs on a shaft drive are very high compared to a chain or belt. I would imagine the gearset alone in the FJR final drive costs more to make than a complete chain/sprocket/belt drive would. The specialized ring and pinion gear requires dedicated machining operations, heat treating, and setup during assembly. Probably why it has changed very little from 1978 comparing to the final drive pumpkin casting on my XS1100....LOL. Carryover that tooling forever to cut costs.

Sooo...what is best...??...depends on what you want to do. Anybody want a shaft drive on their motocross bike...???....I thought not.

 

[RadioHowie]

Oh crap...this thread is going nowhere and fast.
Hey fellas, what kind of chain lube is best for my XQ900 Super-Duper-Racer-Bike? :blink:

The same thing you'd wax your car with....

Ben Affleck spooge.

 

[GunMD]

Naw, this thread was a hit. I liked the part where they made fun of your car.

OK...confession time. Not my car. It was a loaner from an aquaintance. The really wild part? He wadded it up into a little yellow ball about 3 weeks after that picture was taken. What a shame. I'm just glad I got the chance to flog it before he crashed it.

 

[Rickster]

+1 Jestal -- simple man translation:

Chain - most mechanically efficient: transfers power efficiently (but not so much maintenance efficient)

Belt - less power efficient, and remove having to lube your belt -- but still maintain proper tension

Shaft - you lose power to the wheel when you have to go from the shaft to the wheel axle (90 degree bend), but there is no tension adjustment (no stretch of a chain) to deal with. As far as lower maintenance -- it means less frequent maintenance, but maybe not less overall maintenance (spline grease, diff oil changes inspections of u-joints etc.).

 

[pirate]

Aye, nothin' beats a fair wind 'n stout sail. Now, as fer Mr. Constant Mesh, I be thinkin' him to be one, mighty fine fisherman! Arrrrr.