rear sprocket sizing help (15/39 to 15/43)

[Düb Lüv]

i'm trying to figure out if i have enough chain to go from a rear 39-to-43. i bought some new OZs and found a dirt cheap sprocket to get me by until i replace the entire driveline. with the wheel slammed all the way forward i have about 2.5 links of slack by hand. would this be enough? if i'd help i can post pics.

[koko64]

Hi DL

I've got a '95 900 and have made enquiries about the OZ wheels.
Sounds like it'll be close, but I can't be sure without seeing it. 41 seems more possible. My experience has been that you usually need more chain than how it appears.
You are gonna pull some big wheelies with that gearing ! Mine slams into the shift light (set for 8000rpm) with 15/39 gearing which is stock for that year Monster in OZ. I would actually be shifting at 8500 or so with my jaded reflexes

Looking forward to hearing how the new wheels go and seeing pics.

[Düb Lüv]

yeah i know it's not the best gearing, but the sprocket is only like $20.

i know what you mean about needing more chain than it appears. it's not like, ohhhh i have 2 links extra, i can get a sprocket thats +2 teeth. i did some measuring and found that the 43 tooth sprocket has about a 2.6in increase in circumference, increasing the diameter to about 8.3 inches. my 39 tooth is about 7.5 inches diameter.

what sucks about the wheels, i decided to swap axles. going from 20mm to 25mm. i'm not sure how it's going to go. but if i'm having too much trouble trying to get it to work , motowheels said i could exchange the front 25mm for a 20mm for me.

[koko64]

20 bucks, sure is a bargain. If it don't fit you could wait til the next chain/sprocket change and go a 16 front if it will fit. It would be tight in there, not sure..

Cant wait to see the wheels as I have been thinking about them myself and there was a bargain available down here. Just out of reach for me at the moment, but lusting.