Georgewarn Posted January 9, 2012 Share Posted January 9, 2012 I was wondering if you can fit a yz125 gearbox into a xt125r? Need a bit more speed out of my bike Link to comment Share on other sites More sharing options...
PeterC Posted January 10, 2012 Share Posted January 10, 2012 I find downhill is good for a bit more speed Link to comment Share on other sites More sharing options...
Georgewarn Posted January 11, 2012 Author Share Posted January 11, 2012 Thanks I'll keep that in mind but would prefer a better answer about the gearbox Link to comment Share on other sites More sharing options...
KirriePete Posted January 12, 2012 Share Posted January 12, 2012 Be warned that without a proper intro in the cunningly hidden (in plain sight at the top of the forum) New Members section, you are making yourself a target for the pithy wit that this site is famous for, something to do with folk posting a question, getting an answer then buggering off never to be seen again.... Having said that - it's a 12bhp 125 4-stroke single - how much speed can you possibly get out of it? Even if you could bang in the internals from a YZ 'box, the ratios are probably all wrong for a (relatively) slow-revving 4-stroke, they'll be fine for a buzzy, peaky stinkwheel with a powerband as wide as a teenager's attention span. So, you could try fiddling with the sprockets - up on the front/down on the back may give you a higher top speed, if the engine can pull it, but reduce your acceleration. Smaller front sprocket/larger rear will give you better acceleration, but may reduce top speed - it may not as the lower gearing may allow the bike to pull enough higher revs in top gear to compensate. I wouldn't recommend a smaller front sprocket, however, as the tighter turn involved can knacker your chain much quicker. Also be aware that if you increase sprocket sizes you are likely to need a longer chain. Or just get a bigger bike. If you haven't passed your test yet, get it done before the new rules come into play. HTH Link to comment Share on other sites More sharing options...
Ryan09 Posted January 12, 2012 Share Posted January 12, 2012 You wont be getting much out of an xt125 as its what it is a, a 125 4 stroke dirt bike. No chance in getting a yz gearbox in there, wouldnt even think about it. As said save up for a bigger bike, money better spent. Link to comment Share on other sites More sharing options...
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