Speedo drive ratios

Anyone have any insight on this subject? I want to change the dash on my Guzzi but I don't think it's as simple as picking any speedo I like the look of. I've been trying to find out the drive ratio of my speedo - someone suggested 1:1, but I've no idea what that means.

All I'm after is a straightforward speedo that gives me a better idea of what speed I'm doing than the crap original. Anything with the same drive ratio as the Veglia will do...

I might be able to help, I design gauges for vehicles for a living. if you have been to Stafford bike show in the last couple of years we were there as http://www.smithsspeedos.co.uk/

I met Miffa there one year

the ratios 1:1 or 2:1 is for the gearing required from the speedo drive to enable the speedometer to read correctly.
lets say hypothetically your front wheel rotates 1000 times per mile and the speedo is geared also for 1000 turns per mile then this is 1:1 or your wheel might turn 2000 times per mile however your speedo is geared for 1000 turns per mile hence 2:1 ratio



we offer fully programmable speedos, there is a sender that will plug into the cable drive and convert the turning motion to electrical pulses.

you will not need to worry about drive ratios of calibration, as our speedo's have a ride to set function. basicaly when you start in setting mode you ride 1 mile the press the set button again. the speedometer will be calibrated to your wheel and tyre.

Now that makes sense!

I've already bought a digital dash, but I'll certainly keep your details if I may. I know of at least one other guy who's planning to modify his bike, and he's likely to ask exactly the same question.

fig wrote:

Now that makes sense!

I've already bought a digital dash, but I'll certainly keep your details if I may. I know of at least one other guy who's planning to modify his bike, and he's likely to ask exactly the same question.

I have been very busy at work so I havn't visited this site for a few weeks, so missed your question in September.

no problems with my details , I am here to help.

ps I help design and build the speedo on the Gladstone motorcycle, the bike was currently on display on the carole nash stand at the NEC. http://www.gladstonemotorcycles.com/motorcycles/gladstone-no-1/