Ordered a Kenda k772 Parker DT front tire and a liteloc.

 

What are the tube sizes for the stock tires on 09 klx250s?

The numbers on the tubes dont coincide with the tire sizing as near as I can tell.

Fr=3.00x21
Rr=4.60x18

 

This usually isn't an important comparison and often not even realistic. Most tubes have a decently large span of fitment rather than a specific fit. As long as you don't get hold of a really small specific tube size to install in a large tire, you won't have a problem. Tubes suck so much anyway, you really have to put a tiny tube in a big tire to screw it up. Of course you can end up trying to put a really large tube in a really small tire, and this can make pinching the tube during installation likely. Even then, with some care you can use a larger tube without too much issue. The fact that we can use a 21" tube in our rear 18" and 19" tires in a pinch kind of shows how relatively "non-critical" this issue is. Heck...we all know how somewhat different that these alleged tire sizes can be when compared to each other, so if you get a tube that's decently close or inclusive of your marked tire size, you're good to go.

Frankly it's a shame that the dirtbike venue hasn't been more aggressive in pursuing the tubeless tire application. Even serious mountainbikers have been moving away from tubes for years now. Tubes are an antiquated and problematic item that need to go the way of the dodo.

 

okay, found the conversion in a catalog at the motorcycle shop.

Fr = 80/100x21
Rr = 110/100x18

 

Have you thought about going with the Tubliss system? I've been running them for almost 1000 miles now, zero issues. My son runs them as well, and he got a puncture a couple of weeks ago, and rode it home with a flat tire (a couple miles of dirt and 10 miles of pavement). No damage to the tire or rim from riding it flat.

 

I took my bike for an early season ride around the block last w. I wednesday evening and was just turning a corner at an intersection in my hood, and as I braked slightly to make the corner at about 5 miles and hour, the front inner tube blew. The front end washed out so fast that I hit the ground like a ton of ****. I ended up with the usual scrapes on my right side shoulder elbow knee, and a possible broke rib or two. I went to emerg yesterday morning because it hurt so bad I thought I should check for internal bleeding. I had an ultra sound and good news is no internal damage or parasitic twin or anything like that. I got around to taking my tire off to see what could have caused the problem, and found the valve stem torn off. I have never been a fan of rim locks on the front but along with my uhd bridgestone tube I will be ordering a rim lock for front and back of the bike.

 

Wow!, glad you weren't hurt more seriously.

 

Sorry to hear about your fall, hope you mend up well.
I'll keep my story brief.
Couldn't get up a wet greasy hill, dropped rear tyre pressure got up the hill but ripped the valve stem. Replaced the rear tube with a 21" tube which did the job and in fact I rode for some time until I replaced it with a H/D tube and 1 rim lock.
On a long hill climb ripped the stem again, was told in future leave the nut loose on the valve stem, never had a problem since.
Had to balance the rear with weights for road use, never needed a rim lock in the front.

 

That's a good story-example. Sorry to hear about the broken ribs and scrapes, but good to hear it wasn't worse. Though why are you (or were you) not a fan of rim locks on the front?

 

Rim locks on both sides for this guy.. And yes, I had to balance them.

I run low PSI.