Hi all, I decided to try a belt drive primary to save oil drippage and a bit of weight (I take any opportunity to help the old legs and back)
After fitting, I gave the clutch centre a twist back and forth, and it felt stiff and not smooth at all. I took it off and removed the thrust washer that sits between the drum and the rollers, and it seems to be ok now, just a wee bit of in & out play. Has anyone else fitted one of these? (The belt has no adjustment for slack)
Send it back and get a Bob Newby belt drive. It's a little more but it's a complete clutch, you'll also eliminate the annoying basket wobble and torque slip that you get from a worn Cush drive.
As for thrust washer, there were different ones over the later years. Also a new clutch centre to match it. If you get the Bob Newby you won't need any of it, goes straight onto the main shaft and is much lighter.
Please be forwarned that a Bob Newby clutch is NOT a direct replacement. There are many issues with his clutch even though it is a beautiful part. I have been installing one on a 1964 Spitfire Hornet but the first issue I faced was that the belt drive hub was not in good alingment with the clutch basket. The clutch hub basket stuck out too far by about 1/4" or a little more. Closer ispection revealed the taper on the clutch hub didn't quite match the transmission mainshaft. After machineing the clutch hub for a good taper match, the belt now aligned but because of the wider width of Newby's drive hub, the stator bolts weren't long enough for the alternator to work, I had to TimeSert the case, purchase imperial longer studs, and do extra machining for everything to work. I have written all about the installation, with many photos, in posts #17 & #18 of my blog, maasmoto.com (http://maasmoto.com) Although I still think this clutch is a very well built part, be prepared for a lot of extra maching and labor.
Hi,
I removed a belt drive from my long stoke 750 A65 as I preferred the original triplex chain. Keep in adjustment and they will last well over 30,000 miles, as in my A65 650T, and are very unlikely to suddenly fail. A belt may be quieter and the aluminium parts may be lighter and they can be run dry but is this a good trade off for longevity and reliability.
After doing over 3 times the life of a chain I am contemplating a new clutch for my 150,000 mile 650 but it will more than likely be an SRM complete clutch, crank sprocket and chain. It will then be good for another 150,000 miles but I may not last that long.
If you want to save some weight there are alloy clutch baskets available but how long do they last?
Leaks can be over come with good prep, good gaskets and the right sealant.
Dave.
It's a +1 from me for SRM
Fitted one to my A65L excellent bit of kit.
Cheers
Ian
Bob Newbys advert for the gold star clutch is a bit off putting . engine numbers have obviously been doctored .
Just an addition to my original post - the rotor was binding slightly despite the usual checks. Turned out it was binding on the belt drive pulley behind it, fitting a washer to each stud behind the rotor sorted it. The engine is running, but I havent road tested it yet.