I'm trying to get a set of 18"/21" wheels for my KLX300SM. Can anyone help me out with what is compatible? Will any KLX250 dual sport wheel from 2009+ be a direct fit with the same spacers and everything? I know the front rotor is different so I was already expecting to swap that over.
I assume the speedo will be incorrect unless they have different gears in the pickup like what I saw between the dual sport and sumo DRZ. Is there any way to recalibrate them or will I just have to deal with it?

 

From what research I've done, they should all work. Rear wheels actually have a wider variety beyond the 2009 model. The front needs that electronic drive setup.

 

Random thought, how would the bike handle on 18s front and back? 4.10 on the front and 120 or 130 in the rear?

 

Seems like you'd be limiting your tire choices, no? Would the idea be to run a scrambler style tire that might handle better on-road than 21/18 but still give you some dirt traction?

 

I’m pretty set on the Shinzo 705s as I have yet to find something they aren’t good in besides mud

 

I’m just curious how the handling would be compared to the 21/18, as I do way more road riding then ever but don’t really want to do 17s

 

If I did an 18 on the front I'd run a 100/90-18 front and a 110/90-18 rear The narrower tires would draw less power and work well on the road.

I have run a 21/17 set up on my KLX650 for about 50,000 miles riding a lot of pavement play chasing friends on supermotos. I ran Duro Median dual sport tires and could hang with them in the turns, they got me with more horsepower on the straights. On my 250 I am running the 21/18 running the Duro Medians as well, but using a 4.10-18 rear instead of the 120/80-18. Uses less horsepower and works better in sand and mud The narrower tire doesn't bog down as easily.

Tire choice is the player in what should be done. I saw a rider at a NASMoto supermoto race around 2004, running a clapped out Honda XR600R with a rough Dunlop Sport Elite on the back and a 3.00-21 Metzler ME-33 Laser street tire on the front. He was beating new 450 KTMs with that set up. Of course it was a lot of his ability to ride, but the tires were far from cutting edge.

 

That’s good to hear, I’m not the best rider in the corners but was curious if an 18 front would make that much of a difference for the cost of a conversion. The 120 in the back with the 351 kit feels awesome to me. I’ll probably keep the 21/18 setup, just a slow time that gets the brain thinking.

 

I'm still no where near as comfortable with my 250 as I was with the 650, it takes time.

 

I ordered the oem 18/21 wheels from the 2022 klx300 for my 300sm from rockymountainatv.com. It took almost 3 months to get them but I couldn't find any used wheels of the correct year for the front and I needed the correct rotors as well since there's no aftermarket ones.

If you go that route, the wheels come with the bearings and spacer tube installed. I wasn't sure so I ordered everything and now have spare parts.