Bonneville America Forums Forums Technical Forums Performance Mods sprockets !!!!!!!! ratio?????????

when I had nothing done with bike .....
ok !!!!no AI and long Tor's
had 41 rear sprocket
and 19 front one

was ok !!!it stopped me to loking for 6th gear but now when I got my Epco fitted and bikes feel that rides stronger I started again to look for 6th gear!!!!!!!!!
have no idea about ratios !!!!!!

Any advice which sprocket should I change and number of teeth please

if it bothers you that much maybe change the rear sprocket

Frank

for 42 ??????????

or 18 on front?

i would try 42 with the 19, then if thats to high maybe 18 with the 42. going to be a guessing game until your happy

Frank

I ordered a 43 tooth rear sprocet from dennis kirk, Brand ( JT). Course it didnt fit. Has anyone replaced their rear sprocket with anything other than the stock 42.

let me think...............have to contact my sprockets source

I've got a 43 on the rear and 18 on the front. Mine fits coz it was a custom made job. I didn't particularly want it but it was what he had in stock at the time. Not a lot of difference (as you'd expect). I read somewhere that changing the front by one tooth is about the same as changing the back by 3 1/2 teeth.

Matt

no problem for me to get 43 rear and 18 on front but thinking if thats will work better

Grzegorz, If you feel that 19/41 is not a high enough ratio, you don't want to go to a 42-43 or change the front to 18 as it will create a LOWER ratio than you have. Going up on the front will create a higher ratio, going up on the rear will create a lower ratio. Each front sprocket tooth is the equivalent of about 2 1/2 teeth in the rear. If you are still "looking for 6th" and want a higher ratio, you may need to try a 40T rear sprocket which would be just a little higher than where you are now. Personally, I think that seems way high for this bike. I'm using 18/42 and can't imagine using a higher ratio. There are times I wish I had the low end quickness of the 17 back. The exhaust and carb mods have offset the 18 change enough for me to leave it as it is.

Once you get used to the extra power you have now, the gearing will seem OK again. The problem with trying to shift once more is not so much that the bike is geared too low, it is just that it doesn't seem right for an 800CC twin to be pulling that well in top gear.

I had not that feeling before I changed exhaust !with long tors and 41 19 sprockets was ok better than stock or it exist in my imagination only??!!

I think that, sometimes, because the bike is now as strong in 5'th gear as it used to be in 4'th, we think we need to shift once more.

Part of it could be that many people, myself included in the beginning, aren't used to running up higher rpms. I usually run up 4000-4500 before shifting where in the beginning it was more like 3000-3500. If someone is used to bikes that have their torque range at lower rpms, it seems like it's time to shift again. It took me a little while to realize this bike wants to be up there and is quite happy being there.

Grzegorz, Don't listen to Frank. as Ramsound has pointed out, he's going the wrong way - may not have understood what you desired.
If you want to eliminate that feeling of "Ok I'm nearly at the hiway speed limit now, I'll just drop it into top gear -OH WAIT, I'm already in top gear!!!" You need to INCREASE the FRONT or DECREASE the REAR sprocket. If you do not know what effect each will have make a chart (divide rear sprocket teeth by front) OR refer to the chart below.
Rear sprocket teeth on left COLUMN, front sprocket teeth on top ROW
Simply look at the difference in values between what was standard on your bike, and where you are now (what sprockets you have on now). Then decide if you want to make
another minor change or major change.
___14__15___16__17__18__19
49 3.50 3.27 3.06 2.88 2.72 2.58
48 3.43 3.20 3.00 2.82 2.67 2.53
47 3.36 3.13 2.94 2.76 2.61 2.47
46 3.29 3.07 2.88 2.71 2.56 2.42
45 3.21 3.00 2.81 2.65 2.50 2.37
44 3.14 2.93 2.75 2.59 2.44 2.32
43 3.07 2.87 2.69 2.53 2.39 2.26
42 3.00 2.80 2.63 2.47 2.33 2.21
41 2.93 2.73 2.56 2.41 2.28 2.16
40 2.86 2.67 2.50 2.35 2.22 2.11