recomend 47 tooth rear sprocket GPX250

GlennB · Post by **GlennB** » Sun May 21, 2006 6:55 pm

HI all, I just put on a 47 tooth rear sprocket on my GPX250 and what an improvement on exeleration. Also easier to wheelie too

It revs a touch higher on the hwy but worth it. Also dont have to rev the guts out of the bike as much if you need to launch your self off at the lights.
My front still stock with the 14 tooth.
Ride safe
Glenn

mike-s · Post by **mike-s** » Mon May 22, 2006 1:50 pm

how many teeth did you go up on the rear?

Duane · Post by **Duane** » Mon May 22, 2006 2:02 pm

mike-s wrote:how many teeth did you go up on the rear?

Ah but you see mike-s it's how many teeth he'll go down by, when he stacks it wheelying and lands jaw first !!!

GlennB · Post by **GlennB** » Tue May 23, 2006 7:04 pm

Duane wrote:
mike-s wrote:how many teeth did you go up on the rear?
Ah but you see mike-s it's how many teeth he'll go down by, when he stacks it wheelying and lands jaw first !!!

LOL

mike s , I went up 2 teeth.

photomike666 · Post by **photomike666** » Tue May 23, 2006 7:23 pm

It's generally easier (and cheaper on chains) to go down 1 tooth on the front. It is also a slightly more exagerated lower ratio (turns of front sprocket: 1 turn of rear)

14-45 = 3.214:1 Standard
14-47 = 3.357:1 Up at back (requires longer chain to standard)
13-45 = 3.462:1 Down at front (requires shorter chain)

GlennB · Post by **GlennB** » Tue May 23, 2006 7:52 pm

Thought about lowering the front spocket but Didnt want to put the speedo out any further and was going to rev 2 high at 100ks and Ive hear that changing the rear gives that little bit more go than the front too for some reason.
I found that changing the rear up 2 just gave me that happy medium.
I also didnt have 2 lengthen my chain at all, In fact it only brought the wheel in 1 1/2 notches on the trailing arm and still got heaps of room.

wazza1234 · Post by **wazza1234** » Tue May 23, 2006 9:12 pm

how how many rpm is it doing at 100ks now? What kind of acceleration increase did you get?

GlennB · Post by **GlennB** » Wed May 24, 2006 5:22 pm

I think its about 500rpm more. It is noticably quicker and can lift the wheel very easy now. you do loose a little power up high though about 140ks onwards but I wanted more power of at the light and quicker over taking between 80-120 so its done me fine. You will find that the improvement is best between 9-14rpm. I find it just zips through second gear now.
Unfortunatly its not 600 quick though

6 more months to go(or lesser if if Im naughty

)

ozx6r · Post by **ozx6r** » Wed May 24, 2006 6:37 pm

yeah - i went up 5 on rear about 18 months ago and it is great up twisties but crap on highway bout 5500 i think at 100kmh and it helps with the wheelies

ohh and the top speed is now only about 215-220

mrmina · Post by **mrmina** » Thu May 25, 2006 5:48 pm

is this post a joke or what.

u put a big rear sprocket on a 250