I just got a nice black anodized Deore Lx combi uniglide/HG 7 speed freehub off ebay that has a 130.5 mm locknut to locknut dimension. I was hoping to build it up for a 126mm rear wheel. I thought I saw on Sheldon Brown's site where they are taking Deore XT NOS hubs of the same size and converting them for the 126mm frames but you have to buy the complete wheelset. I was just wondering: what method is used to make this conversion? Do I need a new axle? Or can I fire up the cut off wheel and shorten the axle and remove spacers to achieve my objective? Thanks for any help you can give.

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.

I just was looking at a nice, affordable wheelset on the Harris Cyclery website last week. Just now when I did a google search I couldn't find it. It might invovle using a shorter axle, that's what I'm thinking. I just really like the hybrid uniglide/hyperglide cassette body. I can continue to use my old uniglide as long as they hold out and stay calm because of a pretty good back up of HG-70 and HG-90 7 speed replacement cassettes.

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.

is there a spacer between the cone and the locknut? If there are 4mm or so of spacer that you could remove, just try that. Either redish the wheel or take an equal amount of spacer out of each side. If there is spacer only on the non-drive side, you will have to make those non-drive spokes even slacker than they are.

There is most likely a 4 mm spacer between the left cone and locknut. Just remove the spacer and cut the axle down.

Better, however if you have a steel frame, to go to 130, the modern "road" standard. The result will be a stronger wheel. See: https://sheldonbrown.com/frame-spacing. This is a pretty trivial job.

Only cut the hub down if you have a plastic or aluminum frame, but very few of those were made in 126 mm spacing.

Sheldon "Do It Right" Brown

EZ:
1. Find a 4mm spacer on the left side. Throw it away. You don't have to do anything to the drive side.
2. You'll need to shorten your axle a little bit but I don't think that will be very hard to do.
3. If the hub is already laced onto a rim, you'll have to redish it.