Topic: Belt Drive Conversion. Yes I did search. :)

[Don R]

 When the JR Dragsters began to pitch off their chains I did some homework on converting them. Pulley diameter was my biggest issue. There are lots of industrial pulleys and belts available. As far as gates, I use their timing belts on my gl1000. I figure if they can turn the blower on a fuel dragster they have the technology to make a smaller one work too.

[Geeto67]

I once drove past a Harley parked at the side of the highway, with the rider holding up at arm's length what first appeared to be a snake, with a puzzled look on his face. It didn't occur to me until a mile later that he was holding a broken drive belt, wondering WTF he was going to do.

that's actually kind of shocking and I can't begin to imagine the amount of neglect that would lead to that situation.

There was a guy I knew who road his Road King from NYC to Delta Junction Alaska (up the Alcan Highway) and back. Did it on one belt. When he got back we were all hanging around my friend Jimmy's shop while he was servicing it up on the lift. The small pebbles and stones from the trip had taken chunks out of the rear wheel pulley's teeth. Didn't break the belt thought it looked like there were areas that might have been compromised.

The only time I have heard of broken belts is when the pulley fails. I have even seen bikes where the belt tension is set too tight and the belt cracks the pulley when the suspension moves.

[Terry in Australia]

Yep, the belt on my Sportster is 23 years old, and in perfect condition, which is one reason I haven't bothered to do a chain conversion. I still don't think you'd find a belt narrow enough to fit a CB750 that would have the same strength as a chain though.

[754]

Belt would be cool for touring..
 Stock belts have a lower stone guard shield that often gets removed,.pebbles and debris are very hard on belt systems.
 We should check center distance vs the Kawi....see how close.

[HondaMan]

How wide were the belts Mark? Cheers, Terry.

They used the same width for all the bikes at the time, 1" wide. The most interesting part of it (to me) was their testing system: they made strain gages into the hub of a Sportster rear wheel and had wireless transmitters to send the analog (real-time) data to fast chart recorders (1980s, tech, ya know...) and rode the Sporty up to the Eisenhower Tunnel 3 times with a pursuit car behind it. They ran out of paper during the return trip, each time about 10 minutes from Denver, but it gave them the numbers they needed!

[tlbranth]

Didn't read the whole shebang but thought I'd throw this in anyway. Back in the 70's, chains were a total pain in the neck and I'd've given anything for a shaft drive. But....I've had a change of heart. The new x-ring chains are AMAZING. I rarely have to adjust - maybe 2 flats in 12,000 miles! I squirt on some chain wax every once in a while and use a gunk brush with kerosene once/year. Unbeatable. A belt might be good but I'll bet the upgrade would be expensive. I have 4 bikes. 2 have driveshafts and the chain beats them hands-down.

[Terry in Australia]

Didn't read the whole shebang but thought I'd throw this in anyway. Back in the 70's, chains were a total pain in the neck and I'd've given anything for a shaft drive. But....I've had a change of heart. The new x-ring chains are AMAZING. I rarely have to adjust - maybe 2 flats in 12,000 miles! I squirt on some chain wax every once in a while and use a gunk brush with kerosene once/year. Unbeatable. A belt might be good but I'll bet the upgrade would be expensive. I have 4 bikes. 2 have driveshafts and the chain beats them hands-down.

G'Day Terry, yep, modern chains are excellent, folks are putting 520 pitch chains on modern super bikes now to get that tiny bit more BHP out of them, (like a modern sports bike needs any more power........) but Harley has been using toothed belts on their bikes for over 30 years now, and they've proved to be excellent too.

There are plenty of Harleys getting around with 20+ year old drive belts still in excellent condition, which amazes me considering the torque a big twin produces. Even Ducati has gone the belt drive route with it's new "Power Cruiser", the fugly, but potent XDiavel. If it can handle 160 BHP and around 90 foot pounds of torque, then why would you bother using a chain?

It's just a pity you won't find one on a CB750 that hasn't been extensively modified. Cheers, Terry.  

[HondaMan]

Didn't read the whole shebang but thought I'd throw this in anyway. Back in the 70's, chains were a total pain in the neck and I'd've given anything for a shaft drive. But....I've had a change of heart. The new x-ring chains are AMAZING. I rarely have to adjust - maybe 2 flats in 12,000 miles! I squirt on some chain wax every once in a while and use a gunk brush with kerosene once/year. Unbeatable. A belt might be good but I'll bet the upgrade would be expensive. I have 4 bikes. 2 have driveshafts and the chain beats them hands-down.

G'Day Terry, yep, modern chains are excellent, folks are putting 520 pitch chains on modern super bikes now to get that tiny bit more BHP out of them, (like a modern sports bike needs any more power........) but Harley has been using toothed belts on their bikes for over 30 years now, and they've proved to be excellent too.

There are plenty of Harleys getting around with 20+ year old drive belts still in excellent condition, which amazes me considering the torque a big twin produces. Even Ducati has gone the belt drive route with it's new "Power Cruiser", the fugly, but potent XDiavel. If it can handle 160 BHP and around 90 foot pounds of torque, then why would you bother using a chain?

It's just a pity you won't find one on a CB750 that hasn't been extensively modified. Cheers, Terry.  

The 2 alternative drives I saw for the CB750 in its day were: a very exotic (and expensive) shaft-drive kit (on a bike passing thru this town in about 1982), and the fully-enclosed, cast aluminum, oil-bath chain housing. The former looked like it was an adaptation of a BMW rear wheel to the 750 swingarm with a really ugly "bump" of a casting that replaced the chain-drive left cover on the engine. The latter had a pair of bellows (upper and lower, chain passing thru) about 3" long that connected a cast left chain cover that replaced the OEM one, and a rear housing that bolted to the swingarm using both the chainguard mounts (post-K1 models only) and the 8mm rear chain adjuster mount bolt. The only downside I saw to this one (besides the 8+ lbs weight it added) was the loss of the left-side chain-adjuster marks: they were covered by the rear case of the thing, so you had to guess at the wheel alignment. This one sold 2 units from a local shop (who was also selling my old Motorcycle intercoms in those days), both went successfully onto 750K4 bikes. The owners loved them, said they never had to adjust the chain, ever. They didn't leak their 90w oil, either. Ugly, though...