Belt drive

[Honzo]

Did HD invent and/or mainstream the belt final drive for bikes? I've noticed, upon my return to motorcycles, that the Japanese cruisers have them now. I always thought this was a neat idea and kudos to HD for the innovation if it was them. What I really want to know is what would be the drawbacks for employing this drive on any motorcycle, FJR or otherwise? Everything was chain drive once. Why not splined belts? Smoother, high milage, easily changed.

 

[FLOWBACK]

Yes pretty sure H D is responsable for belt deives going mainstream. Width of the belt is a concern when running big tires (Clearence) Lots of power means fat tire,= not alot of room for a belt.

 

[dcarver]

Several con's

1. belt can be 'frayed' if a small pebble lodges into sprocket

2. swing arm must be removed to install new belt

other than that, i've run 3 belts in 140k on my 91 ultra, no problems. They also hold adjustment well, even better than o-ring chain.

 

[IndianaTom]

Did HD invent and/or mainstream the belt final drive for bikes?

My first street bike in the 80's was a 1981 1/2 Kawasaki 440 LTD, It was a blet drive and pretty much maintence free. I really liked it, and put 30,000 miles on it before I traded up to a V45 Honda.

 

[Huck Fonda]

Pros - lighter weight, quiter, less maintenance (than chains), less power hungry (than shafties), long service live (40k)

Cons - as has been mentioned, particulates eat them up, failures can occur very suddenly, limited gearing changes available, driven sprocket heavier than chain sprocket (affects suspension action)

Don't know who invented it, but many many things have been driven by belts in many industries for a long time. I think my earliest memories of use on MCs is also with Kawasaki - GpZ 305.

 

[dcarver]

Pros - lighter weight, quiter, less maintenance (than chains), less power hungry (than shafties), long service live (40k)
Cons - as has been mentioned, particulates eat them up, failures can occur very suddenly, limited gearing changes available, driven sprocket heavier than chain sprocket (affects suspension action)

Don't know who invented it, but many many things have been driven by belts in many industries for a long time. I think my earliest memories of use on MCs is also with Kawasaki - GpZ 305.

Didn't the reallyold bikes use leather belts?

 

[jestal]

There are limits in the amount of power a belt drive can deliver. Shock loads are also an issue. Something tells me a belt drive on an FJR would not be nearly as durable as on a lower powered machine. Elastomeric belts are really not a lifetime drive. They do need to be replaced periodically depending on time, heat, contaminants (oil, grease, etc.). A belt that can carry a significant amount of power does need to be wider. This creates a packaging issue on sport bikes, in particular, where the extra width of a belt (compared to a chain) would be prohibitive.

 

[IndianaTom]

Didn't the reallyold bikes use leather belts?

Catgut

Cat gut is the name applied to cord of great toughness and tenacity prepared from the intestines of the sheep or goat, or occasionally from those of the hog, horse, mule, pig, and donkey.

 

[FJRMGM]

saw a big full-dress HD spit off its drive belt right in front of me - he lives on a gravel road and it was the second belt that had been cut by gravel. Drive belts do not like gravel. Both belts lasted less than 25k miles.

Otherwise, quiet, smooth and pretty much maintenance free.

 

[kansas transit]

Pros - lighter weight, quiter, less maintenance (than chains), less power hungry (than shafties), long service live (40k)
Cons - as has been mentioned, particulates eat them up, failures can occur very suddenly, limited gearing changes available, driven sprocket heavier than chain sprocket (affects suspension action)

Don't know who invented it, but many many things have been driven by belts in many industries for a long time. I think my earliest memories of use on MCs is also with Kawasaki - GpZ 305.

Didn't the reallyold bikes use leather belts?

Yes a lot of the bikes and equipment around the turn of the century up into the 30's used belts that were riveted together in uniform pieces. If you needed to shorten a belt you just took out a couple of pieces to the length you wanted and riveted it back together, however these were very low horsepower engines and I doubt they would take any real abuse. As far as harley making the belt mainstream I guess they were probably the biggest marketers of the modern belt drive systems, but in my opinion the real industry behind high performance one piece belt drive systems in my mind would have to go to the early snowmobile industry back in the 70's. Not only for track belts but also the centrifical belt drives that run from the clutches. Stan

 

[Huck Fonda]

Excellent point Stan, thatnks.

Jestal, with the high torque values of bikes like the Roadliner, is your point still valid? Not being confrontational and don't have hard data, but pretty sure that high torque twin has more grunt than our bikes. Maybe it's to do with the eventual peak horsepower and / or wheel speeds?

 

[kansas transit]

Excellent point Stan, thatnks.
Jestal, with the high torque values of bikes like the Roadliner, is your point still valid? Not being confrontational and don't have hard data, but pretty sure that high torque twin has more grunt than our bikes. Maybe it's to do with the eventual peak horsepower and / or wheel speeds?

Thanks Huck, also note that on a lot of the bigger inch v-twins are going to Twin belt drives to handle more torque output, it also narrows up both belts considerably so there is no real problem with drive belt offset like on the wider belt drives.

 

[Huck Fonda]

Excellent point Stan, thatnks.
Jestal, with the high torque values of bikes like the Roadliner, is your point still valid? Not being confrontational and don't have hard data, but pretty sure that high torque twin has more grunt than our bikes. Maybe it's to do with the eventual peak horsepower and / or wheel speeds?

Thanks Huck, also note that on a lot of the bigger inch v-twins are going to Twin belt drives to handle more torque output, it also narrows up both belts considerably so there is no real problem with drive belt offset like on the wider belt drives.

Hmmm. Haven't seen that yet. Will look around. Thanks.

 

[jestal]

Excellent point Stan, thatnks.
Jestal, with the high torque values of bikes like the Roadliner, is your point still valid? Not being confrontational and don't have hard data, but pretty sure that high torque twin has more grunt than our bikes. Maybe it's to do with the eventual peak horsepower and / or wheel speeds?

I suspect there are a lot of factors. The width of the belt can be adjusted to accomodate the greater loads but that affects the overall package width. The type of power and torque delivered can be a factor as well as the anticipated riding style. Belts aren't really taking over at the drag strip with high RPM clutch drops, for example. A belt might live fine in a lower revving, high torque engine situation where clutch drop holeshots are not common. Conversely, a belt might have a tough life on a 'busa at the drag strip.

Valid comment....??? It depends on the situation and compromises necessary. Seldom is there a black and white or yes/no answer that is totally valid all the time. It will depend on the specifics of the situation. In general I think the guidlines mentioned are valid but there are always exceptions. Just depends on your viewpoint.

 

[Huck Fonda]

Agreed. Wasn't trying to discredit you (yeah, like that's possible), I guess I just didn't articulate the question as well as you answered it.

Thank you.

 

[khrome]

Did HD invent and/or mainstream the belt final drive for bikes?

My first street bike in the 80's was a 1981 1/2 Kawasaki 440 LTD, It was a blet drive and pretty much maintence free. I really liked it, and put 30,000 miles on it before I traded up to a V45 Honda.

gunny! i had an 85 454 LTD .... drove the **** out of it... never had a problem with it...

khrome

 

[FlyingLow]

I call your gunny :lol: .

My one experience with belt drive: I had a Sportster that originally came with the worst POS chain ever put on a bike. I bought HD's belt drive conversion kit and it was right up there with sliced bread.