Higher 5th gear How do you like it?

[mrclubike]

I am thinking of installing the 6% higher 5th gear  or  would a higher final drive be better. I Don't care which one is easier.
(I know all about the shimming and such I have the shim plate and have already rebuilt the Trans )  
I ride in rolling hills with a lot of twisty turns IE MO and ARK Hills
Just wondering if it will be just to high and will find myself just staying in 4th gear more.
I would like just a little more speed  out my sweet spot of 4200 RPM when I am forced on to the highway
Thanks Mark

[nhmaf]

What ratio is the final drive on your bike now?Changing the final drive ratio will of course, also mean you'd need to recalibrate or change the speedometer - unless you go with a different speedometer driven from a magnet on the front wheel or a GPS device.

I haven't dared dive into the gearbox to try to change gear ratios - I don't have the presses and tools needed to work on changing the gearsets anyway.

[Barry]

4th and 5th are very close and would remain so if the final drive was changed. The higher 5th gear would increase the gap between them.

If we assume a 3.44 final drive ratio then at 4200 RPM :

5th gear gives 63 MPH
4th Gear gives 56.6 MPH


A 6% taller 5th gear would give 66.7 MPH
4th Gear would remain the same at 56.6 MPH


Going up one step in final drive ratios to a 3.36 (which was used on the 85 On R65's) would only increase 5th from 63 MPH to 64.5 MPH.


If your final drive is not a 3.44 tell me what it is and I'll redo the numbers.

[Tony Smith]

I am thinking of installing the 6% higher 5th gear  or  would a higher final drive be better. I Don't care which one is easier.
(I know all about the shimming and such I have the shim plate and have already rebuilt the Trans )  
I ride in rolling hills with a lot of twisty turns IE MO and ARK Hills
Just wondering if it will be just to high and will find myself just staying in 4th gear more.
I would like just a little more speed  out my sweet spot of 4200 RPM when I am forced on to the highway
Thanks Mark
 

For rolling hills the higher 5ht gear is always going to a winner, raising all your gears is not kind when it comes to hills.

I have a very worn 32/10 that i was thinking of fitting to my bike, curiosity got the better of me and I fitted it, went for a ride and took it off. It will now be going onto the wife's R65 which mounts an R80 engine and will cope much better with all 5 gears being higher - my R65 will get a raised 5th gear.

[mrclubike]

I just had the Trans apart should have put one in it then but ran out of money.
Thanks for the replies  

[John M]

I have the taller 5th gear fitted to my 1986 monoshock R 65. the final drive is 3.36. I have found it a very good and not disturbing the lower gear ratios gives a great balance between lower gear acceleration and a more relaxed engine when cruising. The bike pulls the taller 5th with no problems and if I want an extra kick for fast passing I just drop into 4th.  

[mrclubike]

Thanks John
I do find it odd that the higher ratio only requires that changing of one gear. I guess  only 6% doesn't matter that much  

[Barry]

I do find it odd that the higher ratio only requires that changing of one gear.  

Yes it's clever stuff how them mange to add a tooth and keep the gear the same overall diameter.  You would think there had to be a compromise somewhere and I'm sure there is but the airhead forums are not exactly awash with complaints of these special gears wearing out so they must be well engineered. I think I've only read one negative comment over many years.