• Welcome to the forum website of the Vincent H.R.D. Owners Club.

    Should you have any questions relating to the Vincent H.R.D. Owners Club, or Vincent H.R.D. motorcycles in general, please contact Graham Smith, Online Forum Webmaster by calling 07977 001 025 or please CLICK HERE.

    You are unrecognised, and therefore, only have VERY restricted access to the many features of this forum website.

    If you have previously registered to use this forum website, you should log in now. CLICK HERE.

    If you have never registered to use this forum website before, please CLICK HERE.

Wider twin gear ratios


Hello Folks,
Does anyone know of anyone making a twin gear cluster with wider overall ratios. This would allow a lower bottom gear for round town use and a slightly higher top gear for motorway use, needless to say on my outfit. Or, has anyone attempted to do the G6 Mod as described by PEI whereby a ? smaller G6 is produced to widen the overall ratios.
Many Thanks, ET43

Tom Gaynor

Well Known and Active Forum Website User
VOC Member
Wider gears

You can't get a higher top except by changing the sprockets (which of course also raises all the ratios. This is because all "British type" boxes have a direct drive top, which by definition is 1:1. It was only with the advent of Japanese boxes that "overdrive tops" came into common use. Maybe modern Triumphs have them, but I don't know of any others. You could however look at the ratios of the various 5-speed options because it isn't unusual for them to spread the ratios better and have a lower bottom than the 4-speed they replace.


Well Known and Active Forum Website User
VOC Member
Wider Gears

Having fitted a 5 speed cluster to my twin I have found that 1st gear is higher then the original 1/2.6.
The Surtees Box is 1/2.458 and makes 1st gear set off a bit high in the revs.
the intermediate gears seem well placed. top is 1/1 as standard.


Hi Tom, and thanks for the reply. I have evolved gear ratio tables for pretty well all HRD and Vincent machines using all RWS's from 45 to 60 T, and some with smaller gearbox sprockets for trials use. I also have ( in 40 years on ) tables to work out altered ratios and speed and revs if anything is altered. If anyone wants copies, I can send them via snail mail as this local yokel does not know how to send attatchments, yet! Cheers, ET43
Warning! This thread is more than 16yrs ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.

Photos from the 2022 North American Rally

Photos from the 2022 Annual Rally

Photos from the 2022 French Rally