Would you use the 13/47 in combination? I have a 13 in front, and a 48 on the bench I'm debating...

 

I did use it riding off road and in deep sand. No problem, a good set up that saves the clutch fpr sure. On the road it was definitely singing, doing 6000 at around 50, but darn good for actual off road. I'll likely go back to that again or a 14/47 next spring, maybe sooner.

 

The KLX300 came with a 14/50 (IIRC), which is equivalent to the 13/47 and is an awesome off-road gearing set-up. But like Mark says, you'll be screaming at highway speeds.
If you do it right, with one chain you can run all three combos, 13-15/47.

 

I broke my new chain a link or two too short to do the 15. That's why I put on the 39, it's what I had on the shelf. I did the 15 with it just to see how it did on the road. Good for road riders for sure.

 

I'm not running much highway, other than road segments between trails and some windy back roads. Definitely no highway use, and nothing wider than two lanes. I think I might try the 13/48 and see how it goes. Thanks for the notes, guys!

 

BTW, I think a 108 link chain is what you want. Stock won't work.
Double check that with a search, just in case my memory is not so good.

 

Yes, 108 I think too. But if you can, be safe and get a longer chain and cut to length. If you think you'll do a 13/14/15 up front, as your riding changes, get the longer chain and spend some time fitting so that the 13 and 15 will both fit. My experience tells me its not easy, perhaps not possible, to do 13/15 some certain combinations (IIRC 45 and 51 rear).

 

I'm not against making a 99 link chain, then keeping a 5 link and a 7 link chain in the toolbox and using two master links. (or any combination thereof, as long as the long chain + short chain + 2 master links = 106 or 108) That makes changing out gears easier, and I don't have full length chains laying around going unused.

 

I've done just that on many singlespeed mtn bikes. I'm still a little wary of doing it on a motorbike, but it should be OK.
With one chain you just swap the front sprocket and adjust the chain. One less step, but your wheelbase changes a bit from gear to gear.
If 2 masters is really safe (I'd stock up on extra clips), it would be a slick way to do it.

 

quick question for trail riding and dirt/gravel fire roads, where I never get above 45 for anything over .5 mile stretch, which would be better 15 /51 or 13 / 45. I am leaning towards the 15/51 as less binding on the chain. But wondered if anyone had one experience with the larger rear sprocket set up. 2006 KLX250s stock, used only for trail and fire road riding.