Getting the gearing right

[sbrumby]

After some time of running the VF I have changed the final sprocket 44t down to 40t which is a 10% increase in speed, gone from 70mph to 77mph, and it does it, tried it yesterday. Easy to change, only took about 1 hour, didnt have to shorten the chain either. The difference is, before the change 6th gear was an acceleration gear, now it is a genuine overdrive. So now 5th wacks me up to 70mph and 6th lowers the revs but with faverable conditions allows 77mph. I have yet to prove this but I think it will result in higher mpg which before stood at 120mpg towing the 1 wheeled trailer.

[Diesel Dave]

Spot on Sam,

Next thing you will be mucking about with max rev settings and turbo's

[TedV]

I've done the same with my gas CB250, fewer toothed rear sprocket. Have the same results, 5th is cruising HWY gear. I don't really notice the loss of gearing around town unless I try to lug it in 5th. It improved my fuel economy more towards 70 MPG US than the around 60 it used to be. Top speed is still in the 72 to 78mph GPS verified depending on tailwind, etc.

What chassis and year of VF did you use again? I looked at a VF500 and it measured too small for a V-twin diesel. I'm guessing you used a VF750 before 87?? with a RD350 gearbox?? I tried the old search here found some pictures and bits o info, but my lunch hour is up. back to work for me

[sbrumby]

The bike used was a VF750 1983.