Originally Posted by HillRider
Respacing the frame, or just stretching the dropouts during wheel installation, was my first thought too.
The current axle will be a problem if the OP elects to reduce the spacing to 126 mm. A too long axle will project past the outside faces of the dropouts and keep the qr skewer from tightening down properly.
Axles can be shortened easily with a hacksaw or Dremel cut-off wheel. You want to shorten the axle from 141 mm (130 mm dropouts) to 137 mm (126 mm dropouts). One suggestion, thread a couple of locknuts onto the axle before cutting so they can "chase" and clean up the cut end when you remove them.
I'd rather not fool with the frame spacing. I would like it if it slides right in without wrestling with it. I'm almost tempted to just order a 137mm axle that has the correct threads for a Shimano rear axle.