Originally Posted by barba
Could you link to where you saw this? I am not sure that it can be done. The axel isn't the issue, it is the length between the locknuts that actually make contact with the frame. You could re-space the rear dropouts, or your frame may have enough spring in it to accommodate the 4mm needed. It may be a little more work removing and installing the rear wheel though.
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.