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Doug Bryant an ACT based BM expert suggested that I could go for a high ration 5th gear, for my R80 with a Siebenrock grunt kit.
I found this gear on Moto Bins web site and was wandering if anyone has gone down this route. I could just change the final drive.



I'm not unhappy with how it's going now, as most of my riding is on fairly tight, bendy stuff anyway, but the lower revs in top would be good.

This is a proposed mod and definitely not urgent, I'll wait till I have to do the clutch or something back there.

cheers Malc0m

I would do the final drive change first...of course that requires a change in the speedo unit to keep the readings consistent...or you just have to remember what the correction factor is. I'd put off the internal gear change until you have to be inside the transmission. Your R80 is in the range of transmissions where the circlip was left out and there's a chance that you'll need to get inside to fix that. At that point, you could do the gear change. Conversely, if you wanted to resolve the missing circlip sooner than later, do the gear change now.

Kurt in S.A.

SteveD wrote:Mal...I think Jeff did that with less than great results?

Steve, I couldn't conclude that the taller 5th caused my gearbox failure. No one else has reported any issues........

Not much of a rev drop, Mal. But every bit helps.
I needed a new 5th, so the decision was easy for me.

You say the gearing is fine on the twisties so that's the lower gears. If you change the final drive you will have taller gears in all the gears. I would say the taller 5th gear is for you.

Opening the gearbox just for this gear change doesn't make much sense but if it has enough miles that refreshment is in order and could use the circlip mod then I say you have enough reason to go down this road. Gearbox rebuilding usually means sending it out to a pro not the corner general repair shop no mater how good they are with Triumphs or Harleys or whatever they deal in.

A different FD does mean a different speedo.