Originally Posted by wheelbender6
The Kleins are great for mountain biking but too brittle for motorizing, in my opinion. Tensile steel (older than 2000) or chromo frames are sure bets for durability. I initially motorized a chromo mountain bike, but found that it steered too quick at speed and the seat height was fine for mountain biking but too high for a motorbike while waiting at traffic lights. I think you can build a nice thumper for a grand.
Thanks, you confirmed my thoughts.