xr hill climbing machine?

Ok, call me crazy call me what ever you want.... Been watching some montee impossibles over here thats (hill climbing in english) The guys over here use heavy powerfully modified street motors dropped into homemade frames, chopped up frames and all sorts. Big car tyres with bolts sticking out for traction. The hill is steep but in stages. The smaller more manouvarable bikes seem to do better.
Has any one ever heard of any one sticking a long swing arm on the 650 with a paddle tyre and given serious hill climbing a bash, or I am just dreaming.

I don't think our XR650R has the power for hill climbing. Over here, a CR500 is considered minimum. Not even a KX500 because the power delivery isn't as aggressive as the CR which has a more vertical ramp up on the hit. For 4-strokes over here, the XR650R builds speed rather than snaps it out. A local guy here in town uses a Yamaha FJ1200 engine ins a CRish looking but custom frame.

I used to ride street bikes in college. I had an FJ1200 for a long time and loved it. One of my two favorite street bikes. Oddly, the other was a Honda CX650T I had until an old couple ran me off the road on MT Baldy in LA. Woke up in the hospital on morphine. Wow, morphine is really good ...

Some FJs:
http://images.google.com/images?hl=en&safe=off&client=firefox-a&rls=org.mozilla:en-US:official&hs=kqk&ei=3jbzSd-KOYbksgOVmfHcCg&resnum=0&q=yamaha%20fj1200%20in%20europe&um=1&ie=UTF-8&sa=N&tab=wi

One of the XR Gurus had a fine shot and description of an extended XR650R swing arm. I think it was over at Thumper Talk on the XR 650/600 forum.

Hill climbs are fun to watch.

funny I came across this, I am getting a spare swing arm lengthend as we speak. I will throw in some pics and prices when I pick it up