Supermoto Question

[Triple J]

So, I want a dirtbike and I also want a Supermoto. The SM would be for track riding, not street.

The dirtbike I've pretty much decided on is a KTM 250 XC-F (maybe just an XC). Four stroke, and good for trail riding which is what we have around here. I'm not too worried about it being underpowered on the SM track, as the track is small and if I really like SM riding I can always upgrade later.

My question is can this be faily easily (about 1-2 hours work) swapped back and forth between SM and dirt duty? Would this just require new wheels & maybe rotors? Suspension issues between the two uses, or anything else I'm not thinking of?

[Grampa]

Are you sure you don't want a nicely equipped RMZ 450
 I would think it should only take a couple of hours to swap the track parts out. Depending on any sprocket changes you make.... a second chain may be needed. All i
was did with my suspension was lower the front till it hit the bars and slow down the rebound.

[bikepilot]

Wheels, front rotor, front caliper/bracket and front MC (swap the front brake setup as a complete unit), alternatively you can run the stock caliper for sumo and just swap rotor and caliper relocating bracket.  The stock front brake setup, even with a big rotor, will be less than ideal for sumo.  Figure about $2k-2.5k for a basic SM conversion with an upgraded front brake.  So yes it can be done, but if it were me I'd shoot for dedicated SM and dirt bikes.  Things like engine tuning, gearing, suspension etc. are all pretty application-specific.  Plus you'll probably want the 250F (or better yet the 150) for off road and a 450 for SM.  Its pretty common to see tidy 450cc MX-based sumos for around $3-3.5k so its only about $1.5k extra to have the dedicated sumo. You can save most of that by getting the 150 rather than the 150F for off road use.  Also I think you'll find that the MX-based sumos are a bit more competitive as they'll have more power, less weight and closer gearbox spacing.

[The Mad King Pepe']

suspension

This ^^^

I think you'll want a stiffer setup for SuMo and a softer one for dirt/trails.

[Triple J]

Wheels, front rotor, front caliper/bracket and front MC (swap the front brake setup as a complete unit), alternatively you can run the stock caliper for sumo and just swap rotor and caliper relocating bracket.  The stock front brake setup, even with a big rotor, will be less than ideal for sumo.  Figure about $2k-2.5k for a basic SM conversion with an upgraded front brake.  So yes it can be done, but if it were me I'd shoot for dedicated SM and dirt bikes.  Things like engine tuning, gearing, suspension etc. are all pretty application-specific.  Plus you'll probably want the 250F (or better yet the 150) for off road and a 450 for SM.  Its pretty common to see tidy 450cc MX-based sumos for around $3-3.5k so its only about $1.5k extra to have the dedicated sumo. You can save most of that by getting the 150 rather than the 150F for off road use.  Also I think you'll find that the MX-based sumos are a bit more competitive as they'll have more power, less weight and closer gearbox spacing.

Thanks for the info...I was hoping you'd chime in. That's kinda what I expected, but not what I wanted to hear though. 

[bikepilot]

NP, that should have read 250F not 150F as well, sorry for the typo

All that doesn't mean you can go forward with your plan, it just won't be ideal.  Lots of folks ride SM on all sorts of non-ideal things and have a great time.