Moto Grand Prix
Main Motorcycle: 1973 Triumph TR7RV
Join Date: Oct 2013
Location: Pleasant Hill, CA USA
Other Motorcycle: 1964 Triumph Mountain Cub
Hi Stuart, That's what I suspected. I got the larger ones from Rabers a few years ago as they said some guys think they work better. I tried to install them, but the fit was too tight. The main problem was too long on the long ways. I got the normal ones too so I'd have choices.
I now believe the stiffer large ones are Triple buffers. They measure 17.3x25.9mm measured like the illustration you sent.
The twin ones I just bought 57-1723 UK made measure 16.8x25.3mm long.
The new UK made I just got are the same as the ones I put in last time. Very easy to install.
When removing them they were not very mushy like the rubber was heavily deteriorated, but were soft. I could very easily remove with pocket screw driver & push back in with just fingers without compressing anything.
I can force the larger rebound in but it's a real fight & the rubber bulges so much as to possibly interfere with the side plate clamping tightly so that's not right. Too tight.
My thought is to grind the too large rubber shorter & maybe profile a bit closer to the 57-1723 UK made ones.
Or get the red set from Canada. Have grand kids over for a few days so not much time to work on bike. I'll try to fool around with bike some more tomorrow night.
Really I'm putting perfume on a pig as the spider & rear cover are worn out. I just kind of want to see what happens. I filed the grooving out of slots last time & they are grooved again in 7k miles so maybe they do wear faster after you file them. I need a complete clutch of course. Long term I want to try to get another 5-10k miles out of motor, then complete overhaul with low compression pistons, all bearings, guides etc. The winter of 2021.
Stuart, thanks again for the info. Another mystery solved.