Because you would increase the leverage at the wrong end of the brake. Large pull of lever no discernable affect at brake. Might work bit better using V-brake levers (i know its mtb derived but it'd be cool to see it tried out) Alternatively try BMX caliper brakes or old style roadster caliper brakes, some of these can have up to 100mm reach. In fact get a bolt on U-brake plate and you could try BMX U-brakes.But I'm wondering why you couldn't just use a couple of alloy strips bolted into place where the brake blocks would normally go. Then drill another hole in the plate for the brake block level with the rim.
I know you're meant to be able to stretch the rear dropouts, Sheldon as usual has some words re: this.clockworkgazz":2niuxm3d said:getting the gazzelle up and running for turbo trainer and ecks bargain wheels will be used- cheers mate. However I had to really pull the rear stays apart to force the rear wheel in- take it my bike is designed for a shorter spindle 120 or summit and I have 130 wheels from eck? Will I damage the bike if i run with it or is steel good that way