• Welcome to the Online Forum and 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, Hon. Editor and Online Forum Webmaster by calling 07977 001 025 or by clicking this link.

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

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

    If you have never registered to use this website before, you can do so now by following this link.

Wider twin gear ratios

ET43

Well Known and Active Forum User
Non-VOC Member
#1
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 User
VOC Member
#2
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.
 

petermb998

Well Known and Active Forum User
VOC Member
#3
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.
peter
 

ET43

Well Known and Active Forum User
Non-VOC Member
#4
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
 
Top