Originally Posted by SOLO LOBO
These 50mm's take a 17mm axle, and I think all KTM axles are 17mm from 1997 to 1999 at least (check the parts diagrams)
The wheels carry the same part number for all 17mm years, so yes Jenna, you can run a 125 wheel (same as the 640 wheel)
The trick is to find out how to get the largest diameter brake rotor, which I think roadsacallin' did on is 250cc forks.... check the german company HE for more options as well
Yep, and the trick to big rotors depends on your fork leg (as i have learned the hard way) and what rotor size you want to go with. It is a bit confusing. As I am pretty sure Solo had already explained, forks from smaller bikes have different lugs than the forks from the 640 (and possibly more). This means you need different adapters. HE still makes the adapters (not cheap) and if you watch german ebay enough you can find them second hand. They make a one piece adapter that replaces the entire caliper holder and moves from a 300mm to a 320mm rotor, and they make a caliper adapter that moves the stock caliper holder and caliper out to move from a 260 to a 320mm rotor. They might make more- I am not sure.
here is their address which was a bit difficult for me to find
Here are the 300mm ready forks (Solo's)
and (ignoring the 'incorect' caliper bracket that is bolted on and the 320mm rotor), here are the 260mm ready forks (mine), notice the different lugs,
here is an old HE adapter to move from 300 to 320mm (wouldn't fit my forks but would fit Solo's)
HE sell this for 75,63 €
KTMax sell it for 105,50 €
Here is a set of forks with the different lower fork lugs (like mine) and the caliper adapter that moves the stock caliper holder out to go from 260 to 320
HE still sell this part (not sure of price yet).
KTMax also sells this 105,50 €
I didn't get any stock caliper adapter with the parts I built my front end from, and having gathered two caliper brackets for later USD forks (one for 320mm one for ???mm) I've cobbled them together and have gone a very odd way towards fitting a 320mm rotor.
so far I have about $30-40 in these brackets
(still in mock-up phase)
If I can find a stock caliper holder for these forks for next to nothing then I might get the correct HE extender bracket, we'll see. My 'solution' has sort of grown on me.