Darn belt drives

comnoz · May 26, 2011

Well it finally happened. Started my bike for a little errand this morning and heard an unusual tapping noise from the primary while it was warming up. This is what I found.

I purchased this belt drive in 93 from CRS. I used it that season on my racebike. I installed it in my streetbike in 94 and used it for only 72,300 miles. Had to replace the motor once in the meantime.
Replaced it with the improved high temperature red belt. Have to see if it gives me a little better life.

Jim

bwolfie · May 26, 2011

Only 72,300 miles, hmmmmm, I might have to rethink using my belt drive and stick with the proven triplex chain

RennieK · May 26, 2011

Jeeze, isn't it under warranty still?

Sounds like a maytag.

jeffdavison · May 26, 2011

"only" 72,300 miles?

heck, cam belts in Ferraris are only rated at 25,000, and in an F355 requires an engine out service to get at them (book rate is 40 hours labor @ 135 hours for the service)... ask me how I know ;^)

I wouldn't cry for half a nanosecond about the belt life in a Norton.

JD

comnoz · May 26, 2011

jeffdavison said:
"only" 72,300 miles?

heck, cam belts in Ferraris are only rated at 25,000, and in an F355 requires an engine out service to get at them (book rate is 40 hours labor @ 135 hours for the service)... ask me how I know ;^)

I wouldn't cry for half a nanosecond about the belt life in a Norton.

JD

Does that mean you own an f355 or you worked on one? Wonder what it costs if you don't replace it in time.

I never imagined I would get that kind of service from a belt when I bought it. Maybe I should call Frank and see if it is still under warranty.

Jim

jeffdavison · May 26, 2011

Preventitive mintenence is ALWAYS less costly than after the fact repair from preventable failure. The 5 valve F355 is an interference design... belt goes, then so do the valves and pistons, and assorted collateral bits.

My other toy is red (Rossa Barchetta) with the engine in the middle, just behind the driver, where a proper engine should be in a car.

I would love the belts to last 72.3K in that car. Actually it's the pulley bearinsg that are the weak link.

JD

comnoz said:
jeffdavison said:

"only" 72,300 miles?

heck, cam belts in Ferraris are only rated at 25,000, and in an F355 requires an engine out service to get at them (book rate is 40 hours labor @ 135 hours for the service)... ask me how I know ;^)

I wouldn't cry for half a nanosecond about the belt life in a Norton.

JD

Click to expand...

Does that mean you own an f355 or you worked on one? Wonder what it costs if you don't replace it in time.

I never imagined I would get that kind of service from a belt when I bought it. Maybe I should call Frank and see if it is still under warranty. Jim

comnoz · May 26, 2011

Yeah I bought a Volvo at an insurance company auction one time. Very nice shape but broken timing belt. I soon found out why the insurance company totaled it. Jim

Flo · May 26, 2011

Umm, that don't look like a Commando to me.
What is it? I'm curious.

swooshdave · May 26, 2011

Flo said:
Umm, that don't look like a Commando to me.
What is it? I'm curious.

What doesn't look like a Commando?

Hobot · May 26, 2011

hehe, who'd of thot hobot could help you upgrade your ole Commando.
Remarkable mileage I didn't know was in the capacity of that style belt.

comnoz · May 26, 2011

Flo said:
Umm, that don't look like a Commando to me.
What is it? I'm curious.

It is a MK3 with a couple mods. Jim

comnoz · May 26, 2011

hobot said:
hehe, who'd of thot hobot could help you upgrade your ole Commando.
Remarkable mileage I didn't know was in the capacity of that style belt.

That style belt has been the most durable I have ever used except for a Polychain. Jim

Hobot · May 26, 2011

That style belt has been the most durable I have ever used except for a Polychain. Jim

Hm, or rather - say what! Just how many miles and primary drives have you digested? Polychain huh, will have to look that up.

I fear Peel may end up back with the ole heavy chain gang.

comnoz · May 26, 2011

I have had almost zero problems with belt drives of any kind on street bikes - even hot rods.

On racebikes I have put the test to several different types of belt drives. Once I got over around 80 horsepower on my racebikes the only belt I could get to last indefinitely was a Gates Polychain belt on a custom sprocket and drum. Jim

Keith1069 · May 27, 2011

Stuff just doesn't last these days! 24k miles on my Norvil HTD belt, keep thinking about changing since I know it's not bang on alignment and does create a little dust and fluff between checks.

Hobot · May 28, 2011

Belts weakness is their edges and Jim LTFO not to have found his all piled up and jammed in the alternator and drive pulley some distance from home. Belts don't usually give any noise clues before sudden failure. One half of my Command adventures is meeting people interested in the old gal and other half stranger giving me mercy to carry a show stopper failure back home. A proper tensioned belt needs no tools to remove or replace.

comnoz · May 28, 2011

Well- getting it over the alternator could be a little tough with no tools. Jim

Hobot · May 28, 2011

Hm, ok then after alternator removed, then no tools like a clutch spring puller or moving gear box around. Ya do know you still ain't fully used that belt up yet : )

Oh cool Wes just rode up on his '71 so off to wire up Trixie with most all the factory warts intact.

comnoz · May 28, 2011

hobot said:
Hm, ok then after alternator removed, then no tools like a clutch spring puller or moving gear box around. Ya do know you still ain't fully used that belt up yet : )

Oh yes I have- I cut it off. Jim

lcrken · May 28, 2011

comnoz said:
That style belt has been the most durable I have ever used except for a Polychain. Jim

I've had good luck on the race bikes with 40 mm wide HTD belts, using both Bob Newby and Norman White drives, not so good luck trying 30 mm wide belts. I'd like to have tried the Polychain GT belts, but all my belt drives have HTD toothform pulleys, and they aren't compatible. Back in the dark ages I tried one of the original Bob Oswald drives with the rectangular tooth form belts, and stripped the teeth off almost immediately. I think his later kits used a better belt design.

Jim, have you tried the new Polychain GT Carbon, the latest replacement for the GT2? It looks pretty trick.

Did you make your own clutch basket for the Polychain, or does someone sell a Polychain primary drive kit for Nortons?

Ken

Darn belt drives

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