Potential front brake upgrade
Posted: 01:03 am Jul 08 2025
I'm about to go get a 2009 KLX250SF and start turning it back into a dirtbike from a factory super moto. I realize that may sound stupid, but it's a better deal than on any KLX230 or TTR230 that I was looking at for my daughter or my GF to ride along with me. Key points being lower seat, and not much happening if you twist the throttle all the way.
Well the 250SF comes with 43mm USD forks on it and a 300mm brake rotor, 17" wheels all around. The fork lugs are definitely different than the regular KLX lugs, but I'm pretty sure I saw that familiar old 15mm KDX/KLX axle sticking through them. I figure I have all the parts to turn this back into a dirtbike mostly because I have the KDX 21" front wheel. But that got me to thinking, what about the brake rotor? Well it looks like both the 250SF and KDX/KLX650R all use a 4 bolt rotor mount. So I'm betting that the 250SF 300mm rotor would bolt onto a KDX hub. Then you'd just need to machine out a spacer for the caliper. The guy who SM'd my KLX650R had one done up and I'm hoping it's for a 300mm rotor (stands to reason that's a common size). When I get the bike, I'll see if the rotor mounts onto the KDX rim and see if my brake spacer is made the right way to space it out, and then post pics!
It's been so long since I had the SM wheels on the KLX that I forget some things exactly, and the wheels were mag wheels from a Suzuki SV650 (IIRC), so the caliper spacer might have an offset to it that wouldn't work anyway, but we'll see.
Well the 250SF comes with 43mm USD forks on it and a 300mm brake rotor, 17" wheels all around. The fork lugs are definitely different than the regular KLX lugs, but I'm pretty sure I saw that familiar old 15mm KDX/KLX axle sticking through them. I figure I have all the parts to turn this back into a dirtbike mostly because I have the KDX 21" front wheel. But that got me to thinking, what about the brake rotor? Well it looks like both the 250SF and KDX/KLX650R all use a 4 bolt rotor mount. So I'm betting that the 250SF 300mm rotor would bolt onto a KDX hub. Then you'd just need to machine out a spacer for the caliper. The guy who SM'd my KLX650R had one done up and I'm hoping it's for a 300mm rotor (stands to reason that's a common size). When I get the bike, I'll see if the rotor mounts onto the KDX rim and see if my brake spacer is made the right way to space it out, and then post pics!
It's been so long since I had the SM wheels on the KLX that I forget some things exactly, and the wheels were mag wheels from a Suzuki SV650 (IIRC), so the caliper spacer might have an offset to it that wouldn't work anyway, but we'll see.