I've received a few emails asking questions about my WR250R's supermoto wheel/tire setup, specifically about the front wheel/tire and if any modifications need to be made to get it to work....
Shown above are a few closeups of the front wheel/tire. I'm still using the R models stock calipers and rotors. The rotors bolted right up to the wheels. You will notice that I did have to re-route the front brake line to the outside of the fork, otherwise it will rub on the smaller 17" wheel/tire. I secured the brake line at the top of the fork protector with a small blue Zeta clamp.
Additionally, I had to trim the front fork protectors a little bit. The WR250R fork protectors are slightly different than the ones on the X model, and are designed to work with the stock 21" front tire. So if you put smaller supermoto wheels/tires on you need to cut the fork protectors down a little bit where they are rubbing on the tire so they can clear it. It was very easy to do, but I suppose you could purchase a set of the X model's fork protectors as well.
On a side not, I also put a kickstand from an X model on, which is slightly shorter than the one that comes on the R. If you don't do that, the bike will sit almost straight up and could fall over pretty easily.
Another popular tire setup for the WR250R is to run Pirelli MT-43 Trials Tires front and rear. These DOT legal tires were designed for trials-type riding and competition, but their excellent performance on hard, wet and dry terrain makes them perfect for dual sport use. They provide long-lasting performance, excellent grip on virtually any type of terrain, and are very affordably priced. One side benefit is a tread pattern that has a minimal impact on soil.
The MT-21's work great on the front of the WR250R and will often go 5000 miles before they need replaced. The D606's work great on the rear of the WR250R. They are best suited for off road use, but their tread compound is engineered for good highway durability and grip. You should get around 3500 miles out of one. Both tires are DOT approved.
NOTE: The Pirelli MT-21 tire is billed as a 90% off-road / 10% on-road design. If you think you will be riding alot on the street, you might want to consider a Dunlop D606 Front Tire (size 90/90-21) to match the Dunlop D606 in the rear. They seem to work better on the street.