Topic: CB750 K transmission vs F2 - number of teeth?

[PeWe]

The CB750 shop manual describe the transmission for K0, K1-K6 with gear ratios gear by gear.
Nothing about number of teeth
-Anyone that has a description for F2 transmission?

[robvangulik]

I've been searching deep in my archives (it is 27 years ago i sold my last cb750) and i found these gear ratio's for theF2:
1st gear 2,500:1
2              1,708:1
3               1,333:1
4               1,133:1
5                0,969:1
I can't find the ratio's for the earlier models, but i seem to remember the 4th gear was 34:31, which should give 1,096:1, and the primary drive for the F models was shorter too, but i can't tell the numbers anymore,you could look at hondachopper.com

[PeWe]

Thanks,
I found that too in the shop manual.
I have added the internal gear ratio for F and F2 into the gearing excel file I have found here, hopefully correct. I have adapted it for km/h.

If need to change the kmh to miles, remove the *1,60934 factor I have added on each kmh cell. See the first tab with K where the initial mph is written.

It look like its only gear 4 and 5 that differ. F and F2 has different front vs rear sprocket.

I'm still open for gear teeth numbers if anyone knows....

[robvangulik]

I found this at hondachopper.com for the F1 onwards:

Final drive gear ratio 43/50 i/o 48/50. 4th gear on main shaft 31 i/o 30, 5th gear on countershaft 31 i/o 32

[PeWe]

Final drive gear ratio 43/50 i/o 48/50. 4th gear on main shaft 31 i/o 30, 5th gear on countershaft 31 i/o 32

Thanks! That seems to be the gears teeth and match the internal gear ratio where only 4 and 5 differs.