I have a 2009 klx 250s. I have 13/42 sprockets on it now. I do almost all my riding on dirt roads and on trails. I probably only put about 100 highway miles a year on my bike, the rest trail and dirt road. The bike still needs geared down for trails. What rear size would guys recommend going to 45,46 or 47. I will be staying with the 13 front.

thanks

 

You'll get a lot opinions about gearing combos, but one thing to consider on the rear sprocket is the clearance with the chainguide. I'm running 14/47, and I have to take 2 of the 3 chainguide bolts off and loosen the 3rd so that I can push the tire forward enough to get the chain off to remove the wheel. Now, if the chain is longer, it gets easier to get the chain off and therefore the wheel. I'm not sure where this magic number of chain links and sprocket size ends up, but just be aware that there can be a clearance issue with the sprocket and chainguide in certain combos that involve chain length. Not the end of the world, but better to be informed.

 

Any lower than 13/45 or 14/48 and I think you'll find you've got a five speed. I use the 13/45 and 14/45 combo with a 108 link chain. Can change out the front sprocket in under 10 minutes for long haul rides (14 front.)

 

13-45 is in my opinion the perfect combination. Oh and welcome to the forums. If you get a chance stop by the new member's area and give us an introduction.

 

Thanks for the replies. I have done some research and am pretty sure I will have to get a longer chaing. I do have a 13 and 14 front sprocket so If I do decide to do some long road running I can swap them out. I was leaning towards the 13/45 combo.

 

What is the stock gear combo on the KLX250s ? Is it different per year?

What would be the most teeth you can put on the rear without having clearance issues?

Reason I ask is I will be buying a few sets when I pick up mine soon.Along with a box of different size jets.

Im just a tweak fanatic with everything I own pretty much.

 

14/42
someone on here put a 51 or 52 on, you have to remove the chainguard

 

I started by going to a 13 which was....hum...ok. Changed the rear to a 45 and...WOW! it is exactly what the bike needed. I too use mine almost exclusively off-road and its "almost" perfect. Still can go down the road relatively comfortable up to 60mph. It will go faster but I have no need.

Only downside - you'll need a new chain - 108 links. Not sure if it is workable but I saw a 46 tooth recently. That might be my next move if I don't have to replace the chain.

D