gear modd to gpx250r

rocco · Post by **rocco** » Wed Dec 13, 2006 9:09 am

local mechanic mate has offered to mod the gpx250r so it revs lower at 100km/h by performing a sprocket mod.

anyoen here know how the bike handles after such a mod

it now revs at 7,000 on 100km/h.......what will it come down to once the mod is complete.

is it less responsive at lower speeds?

the big question which sprockets actually get change?

front or rear?

roc

Grasshopper · Post by **Grasshopper** » Wed Dec 13, 2006 10:21 am

cheapest is to change front sprocket - its smaller.

add a tooth on front and it will drop highway revs (dunno where the calculator is though) but acceleration will suffer in proportion to the change.

keep in mind you have what, 30 horsepower to play with here, it is meant to rev a bit.

Stereo · Post by **Stereo** » Wed Dec 13, 2006 10:48 am

If you are doing this to avoid the oil....... dont bother.........

Just live with it...... everyone else does...... stuff a cloth under your set and give it a wipe from time to time, clean your air filter once a month........ When it is time to upgrade, do it

Wanna buy a GSXR600? hehe

rocco · Post by **rocco** » Wed Dec 13, 2006 10:59 am

admittingly no its not for the oil idea as i wont be flogging it that hard all the time......its basiclly to stop is revving like f16 hornet afterburner.

its toooooo loud

Johnnie5 · Post by **Johnnie5** » Wed Dec 13, 2006 11:35 am

yes you will lose a little of the bottom end performance ,

it will take longer to rev out in each gear

each gear will give a higher speed

you may find you need to change down more often when cruising as you drop off the power curve

either sprocket could be changed

the front is the quick , easy, cheap way and you can always go back to the old one if you dont like the change

front sprocket is only about $20

if its too loud you are too old

try wearing earplugs more for the wind noise than enhone noise

its a 250 it is supposed to rev

Grasshopper · Post by **Grasshopper** » Wed Dec 13, 2006 12:24 pm

have a read here too....

http://www.ksrc-au.com/phpBB2/viewtopic ... highlight=

Neka79 · Post by **Neka79** » Wed Dec 13, 2006 6:41 pm

good find grasshopper!!

yea mate...all u will do is slow ur bike down in every way....
slower acceleration.... slower top end..

i wouldnt...id put up with it...

hoffy · Post by **hoffy** » Wed Dec 13, 2006 6:49 pm

Hi Mate, you'll find it will rev at about 6,500 if you go up one at the front, its usually 500 revs down per 1 up at front, from my experience of 250 and 650 dirtbikes, which used to rev at about 5,500 at 100k's. Its pretty normal for them to rev that high.