true, I just prefer the larger front sprocket since it's better for wear. Weight difference is negligible. I've also got spare set of wheels so that one day I can put some road rubber on them and try the bike on the road, was hoping to run 15-42 if there's enough adjustment for chain slack.

TNC - it's an 04 model. I think the previous owner modified the chain guide slightly by 'chewing out' a little of the rear of the guide to allow a 50 tooth sprocket to fit. I hear you about having the rear wheel forward but I'm not sure I'm keen on the idea, it's sometimes hard enough to keep the front down as it is.

Also, I'm not sure how it would go with a bigger front sprocket, with the 15 the chain is already very close to the case. I changed the chain and sprockets only a few months ago just when the chain was starting to stretch and you can see where it was rubbing the case forward of the countershaft sprocket. I have removed the cover over this area so I can keep an eye on it FWIW.

 

Found this old thread so I'll ask my question here. I'm planning a six day backroad camping tour of rough mountain two track with some higher elevation steep trails and creek crossings along with mostly fast forest service dirt roads in central BC.. Problem is I'll need to ride all highway for two days of this trip, there and back with friends on WR250R and DRZ400S bikes, which can cruise at a faster pace. Currently have tried stock 14T and 13T for local trails. I ordered a 15T and wonder if it will work just for this trip. It will be great for highway but will it pull offroad hills ok in 1st gear or is this bike underpowered and I'm dreaming? I could bring an extra 13 or14T but what a hassle to change mid trip, plus the tools needed with extra weight to pack along. 2010 KLX250, stock plus Acerbis tank and racks with soft luggage. New TKC80 knobbies, 120/90-18 rear. I weigh 165. Thanks!

 

If you are stock bore go with the 13t. Even with the big bore 15t is only really good for road/fast fire road use. The 13t lets you approach redline in 6th where the 14t kinda runs out of steam. There are guys on here with a lot of high rpm miles commuting so you should be ok.

 

Ok, thanks for the info. I'll leave the 13T on. I'd like to rejet and open up the breathing but like the quiet too. My former bike, a DR650 was irritatingly loud.

 

Get a KLX300 pipe for it. Apparently they flow like an aftermarket, but are quiet.

 

I have the 300 pipe and muffler on my 351 and it's far from quiet but I did change the end cap.