While the hub shells have the same specs as far as width and flange spacing, and the cones are the same, other parts are different. You cannot jusr remove a spacer to get 120 spacing. The axle is shorter, and the spacer is narrower. I think the cones are the same, and I know the axle ends are also (8mm wide).
5 speed (120 spacing) uses a 129mm axle, and a 6mm spacer, with a 2mm washer, and a 153mm skewer.
6 speed (126 spacing) uses a 135mm axle, and either an 11mm spacer with a 2mm washer, or a 12mm spacer with a 1mm washer, for 13mm total spacing. Also a 169mm skewer, upon which the non-threaded portion is 6mm longer.
While you can cut down an axle, it's a pain, and you can damage the threads in the process. You can thread an axle end on first, then work the end with a file, and back the nut off to rethread it, but you can damage both nut and axle in the process. Even with an axle vise, or two more nuts threaded on the other end and locked together, it's difficult to hold the axle from turning while you back the nut off and cut new threads. The threading is not standard. You can also crack the nuts if you clamp the one's locked together on the opposite end in a vise to keep it from turning.
I don't recommend cutting the spacer down either, becuase it needs to be perfectly parallel on the opposing ends, or it won't sit straight in the drops, and thus won't be properly supported. Not to mention that the spacer is machined out in the center, so it's not the full diameter all the way across. Your cut may end up in the area that is machined down, thus not fully supporting the washer or the cone.
If you run the longer skewer in the shorter axle, you may run out of threads on the skewer before the assembly get's tight enough. It's extremely close. On thick dropouts it barely works, on thin dropouts it does not work. Not to mention you have a long nub sticking out the other end, which catches on the d-ring, and makes the whole thing a pain to loosen and tighten when you remove or install the wheel.
I would just pay the extra bucks and buy a 120 spaced wheelset. Buying a 120 spaced hub and swapping the guts will work, as will buying a hub and building a wheel, but both end up being just as expensive in the long run. Not to mention the cones will be worn to the bearings and the hub. You will need to keep those together, and just swap the axles and spacers. Plus, you will need the proper cone wrenches. The only plus to buying all this is you can service the hubs later when they need regreasing (part of proper maintenance).
This is why the 120 spaced rears and flat QR's cost so much used - they are more desirable, and harder to come by.
IMO the large flange hubs are more expensive because they are rarer, and thus harder to come by. It has been debated on this board which build better wheels or provide better ride quality, with the concensus being they are about equal. Large flange hubs may very well crack more easily, especially on a higher tension [rebuilt/modern] wheel build.
Bill Roberts Jacksonville, OR
-----Original Message----- From: email@example.com [mailto:firstname.lastname@example.org]On Behalf Of Doug Van Cleve Sent: Monday, September 26, 2005 3:09 PM To: Classic Rendezvous Subject: [CR]Ignorant Record hub question(s)
I know about the pre-CPSC flat skewers, but did anything else much change on Record hubs? I am trying to gather parts that at least look right for a 1975 frameset. Is there anything that makes it difficult to remove a spacer on a 126mm spaced rear wheel/hub to use in a 120mm frame (I assume that is what I have)? Are high flange hubs more valuable than low flange? Thanks :^ )
Doug Van Cleve Chandler, AZ