Hi looking at this 2012 KLX 250 with 18000km/11000 miles for 2500usd. My plan is to make it into a supermoto since i mostly ride pavement but looking at other models like the wr250r/x etc they are all few and far inbetween and pricey compared to the klx250.
I would get the KLX250-sf but cant find any available here in sweden so therefore wondering what would i have to do to make it into a sf, does the suspension need anything done to it or is it just sumo wheels, brakes and gearing? Any recommendations are really appreciated even for what brakes/gearing i should go for on a supermoto. Also if anyone has done this around what pricetag am i looking at?
Pic of bike below!

 

Gearing is simple, a 38 (or 39, I forget which) rear sprocket. The expensive part will be wheels, If you look long enough you might find a set from $600 up. The front brake uses a 290mm or 300mm front brake vs the 260mm on the S. The rotor is needed along with the carrier that bolts to the fork with the caliper bolted to it. I'd almost think I'd see about trading the S on an SF. It's an expensive proposition to buy the parts.

I'd just keep pounding ebay, any forum with a market thread. and do searches for the wheels. Just make sure you get 2009 and up wheels, because of the electronic front brake. Earlier models had cable drive with different hub. Probably the least expensive way would be to buy the rims and spokes to lace up to your S hubs. Still probably near $900 without tires.

For about 20 years I rode a KLX650 for everything and it worked great, as my friends found out on their sport bikes. I was running the stock 21/17 wheels with Duro dual sport tires. Now it is possible to get some good road tires, which would last longer. You don't need sport bike tires or 17s to handle well. I rode with a friend on his Aprilia 550 supermoto and another with an XR650R supermotoed. My friend with the Aprilia swapped bikes with me for a while. When we swapped back he commented, "How do you make that go so fast" mainly about cornering. I said 30,000 miles and 15 years. He was much faster and a better rider, but he recognized the bike could perform, especially for what it was. The 250 can be the same. It's just not going to look like a supermoto.

 

One way to make a cheap supermoto is to simply lace up another rear rim onto your front hub.

I did a Yamaha XT225 and it worked great. This is the complete kit I assembled for the project.



The XT225 SuperMoto.



If you do this be sure to lower the rear suspension as a smaller front wheel tilts the bike frame forward and decreases fork rake which can make handling less stable.

 

So you ran 18" wheels front and rear here?

OP, be aware that this setup would greatly reduce your tire selection compared to a true supermoto setup. Supermotos really use 17" wheels, because that's the standard sportbike tire size. There aren't as many sticky tire options in 18".

 

Unless the op is looking to actually race or do a lot of track days having sticky tires for a 250 is honestly a waste. I rode the snot out of a KLX650 with my friends on their SMs; an Aprilia, an XR6650R supermotoed, and a DRz400. I run the stock 17/21 using Duro Median HF903/904 dual sport tires and I wasn't losing too much ground to the better rider on the Aprila. I also saw a NASmoto race at Cleveland, where a rider had what looked like a clapped out XR600R with the 18/21 wheels, shod with a Dunlop 591 Sport Elite and I think a Metzler ME33 Laser front tire (used on customs with 21" wheels. I watched him make a number of much newer KTM supermotos look slow. Plus I believe there is a video by Ari Henning pointing out that a vast majority of sport bike riders are better off using sport touring tires. Says few riders can heat up and maintain the temperature for best sport tire handling, that the sport touring tire will work better for regular road use.

Point being, there are good general purpose Bridgestone has sport touring tires like a 110/80-18 and a 140/70-18 in their Battlax T32. Plus, looking a shade further the Pirelli Sport Demon sport compound tires are available in the same sizes for $282 the set at Motosport. I also know that Bridgestone Batlax BT45 is still available and they have had times where they were OEM tires on sport bikes, may still be. They worked well and virtually always got decent comments in the bike reviews..

So really the myth that sport tires are only available in 17s is kind of debunked. Seems probable that vintage racing and riding vintage bikes probably has good sport touring and sport tires available if you look.

 

I didn't say they are only available in 17s. I said the amount of choice will be reduced, which it is, whether your talking about an r-comp track tire or a sport touring tire.

 

How many brands need to be available? Three, five, twenty?

Bridgestone offers them, Pirelli offers them, IRC offers them, and if I looked into Dunlop, Metzler, and Avon, they likely have them too. It may not be the exact model as the current tires used on the big boy ZX, YZ, CBR, and other big super sports. But if you look you will find that the sizes of those "hot ticket" tires will not go small enough size for the tires used on the SF either. Many are only in the 120 and 170-190 rear. So the fact is even the 17s when on the 250SF are limited as well, from what I understand they won't fit a 150, I know the KLX650 wouldn't without sanding the chain side to clear - with no chain guard. So even the 17s have a problem with availability if trying to buy the latest and greatest super sport tires. I learned a lot of this when considering supermoto-ing the 650 and when looking at tires for the 550 and again for the 700.

For the 250 running smaller 18" I found both sport compound and sport touring compound, gave examples of both that I found within five minutes googling 18 inch sport motorcycle tires.. You may not have a wide variety from all the manufacturers or specific buzzword models, but the tires are available. As I said, the vintage racing uses those sizes and they ain't running junk tires. I also pointed out that for street use the most sensible tires would be a sport touring compound, which is definitely available from a lot of tire manufacturers.

Of course with a bit more research, if sport tires were what is wanted, the original 09 SF had IRC Road Winners on it. My Zephyr 550 has Road Winners on it. It has a 17" front and 18" rear, running a 110/70-17 front and a 140/70-18 rear. There is a 130/70-18 available too, I believe the OEM width of the SF models.. Good handling tires for the road for sure. So instead of replacing the front with an 18, go with a 17 and use Road Winners. Probably more choices if searched. I just looked up what I had. I also had a set of low buck Duro street tires I used, but wasn't as impressed as with the Road Winners. I would also take a look at the Bridgestone BT45s which had a great reputation both on street and track for track day and vintage racing. The Road Winners got good comments in road tests as did the BT45s both of which were OEM equipment on Ninja and CBR small bores in the past and getting good comments and results from the test riders of those bikes.

Admitted the current hot ticket sport tire aren't all available in small 18 and 17 sizes, but then again we're not talking sport bike, we're talking a street ride, and proven quality sport and sport touring tires can be had.

 

Yes. Dualsport tires. What did you expect? I said it was cheap.

 

I'm not knocking that if it works well enough as a budget option, but since OP came here specifically asking how to create a sumo setup, I think it's worth the transparency that 18" wheels are not sumo wheels. They're going to turn in a bit slower than a 17" wheel too. A dual-sport tire isn't a component of a definition supermoto setup.

 

I was up front on what I learned when looking at SM wheels for my KLX, it costs $1500 at the least unless by some luck of the draw one finds a set for less. Rims alone in the proper width will run around $200 each, spoke kits are around $100 each set. I pointed out lower cost options. I gave examples and research on the 18" deal where an 18" rim on the front can do what the OP was asking, for a fraction of the cost of trying to install 17s. I demonstrated that sport quality tires can be had in 18s, after all a lot of vintage bikes are racing on sport tires. I pointed out that sport touring tires are a better choice for a road rider who isn't going on the track for track days or racing. That there actually is quite a choice of tires if one looks. By the way, again, some sport tires are limited to sizes ranging from 170-190 for the rear and 120 for the front, so those are not an option in choice.

I gave my personal use example that the 18/21 will do the job fine with a set of street tires, that even SM type riding can be done with the stock wheel sizes, thus no cost but the more street type tires. I also gave the example of a rider using the old 18/21 setup on an XR600R in racing, outperforming other riders on actual factory manufactured SM bikes.

Then @tooter gave the easiest solution, only swapping out the front rim to an 18", then I mentioned doing a 17" front if buying a new rim. We gave options to get what he wanted for as low of cost as a used 18" rim plus the spoke kit for the front wheel only.

You simply say "it isn't SM", and "choice of tires is limited". It was almost like "the SM 17s way or hit the highway." How much help was that.

Who is offering help and information, being transparent here?

He did ask about prices and no where in the world was SM actually ever limited to just 17" wheels and the looks. Maybe 17s are required at the pure race level, but certainly not at the lower levels and track days. There are a lot of riders using dual sport size wheels playing supermoto on the track and on the street. I know, I am one of them on my KLX650 and 250 playing on the back roads of SE Ohio. As one friend said to me, after riding my KLX, that he had no idea how I rode that bike that fast. His comparison? His Aprilia SVX550 supermoto, plus his better riding skill than me. My response again, was 15 years riding the bike and using the same kind of tires.