Bicycle Mechanics - Axle size for old Trek frame

I know I have a bent rear axle (QR style), but the problem is that it seems to be an odd size. When I measure both the O.L.D, and add the 11mm, or just measure the bent axle, it comes out to be around 133mm, but the problem is that I can't find any information on an axle of that size or anything near it. The closest thing I could find was 137, but I'm pretty sure that would be too long. So I guess my question is, does anyone know anything about axles of that length, or, should/could I cut down a 137mm axle a few mm?

where is this 11mm coming from?

just a bent quick release, or the actual axle in the hub?

where is this 11mm coming from?

just a bent quick release, or the actual axle in the hub?

I emailed Sheldon Brown and he said this

"axles are 11 mm longer than the Over Lock Nut dimension"

Sorry about all the confusion, it is the actual axle that is bent.

where is this 11mm coming from?
Quick release axles are spec'ed at 11 mm longer than the OLD so 130 mm dropout spacing uses a 141 mm axle, 126 mm dropouts use a 137 mm axle and 120 mm dropouts use a 131 mm axle. This allows 5.5 mm of axle stub to stick out beyond each locknut and into the dropouts.

To the OP: If you install a 137 mm axle and the stubs stick out beyond the dropout faces, axles can be cut down fairly easily. A hacksaw and file to clean up the cut end work fine. BTW, what is your dropout spacing? If it's 120 mm (5-speed) the correct length is 131 mm and these are still available.

Well, measuring the spacing turns out that it is 122.5, so I'm not actually sure what it is. If it helps, it is a 1983 Trek 720 frame.

Well, measuring the spacing turns out that it is 122.5, so I'm not actually sure what it is. If it helps, it is a 1983 Trek 720 frame.

Sweet bike, I love Trek 720's. The bike originally came with a 6 speed freewheel, so that would imply 126mm OLD spacing. However, since some folks favored running five speed freewheels on touring bikes of that era, with 120mm OLD spacing, to lessen the chance of broken rear axles under heavy loads, it might be that the bike's dropout spacing is a fudge between 120 and 126mm spacing, so that either five or six speed freewheels could be easily used. At any rate, 122.5mm spacing is not one of the normal standards, but again, five speed is generally 120 and six speed is 126, the frame's dropouts would be required to flex a bit either way.

Here's a catalog link to the '83 720, sometimes called "the best touring bike ever built.":)

http://www.vintage-trek.com/TrekBrochure1983Part2.htm

edit: I just noticed the '83 is specced with a Helicomatic hub, aka the hub from hell. That could be part of the problem, I'm not sure-

Well, I'm pretty sure it is 131 mm. I've got another older rear wheel and the axle is 131 and it fits just fine, so... where might I find one? I'm pretty sure it is 10x1x131 now I just need to find one.


Btw, it's not a helicomatic hub, the bicycle was purchased as just a frame and now seems to have a random assortment of parts, but the rear hub is a Normandy Luxe Competition (High flange). The only information I could find on that hub is that it was normally sold with Peugeot's px10.

Lbs

Yeah, that seems like it might be the best solution

Alright, so I checked with my LBS and they said they can not order one. So, any other suggestions? Should I just cut a 137mm one down?

Yes, a longer axle should be cut down so that the total length is equal to the OLD plus twice the width of a rear dropout minus 2 mm (the 11mm rule is fine, too, but some older bikes have thin dropouts). The axle needs to have sufficient threads for proper cone placement, the end needs to be carefully filed so as to allow installation of the cone and locknut without damging their threads, and the q/r tunnel should be cleared of burrs and debris. I strongly suggest cutting only one end - much less work. I'd suggest the lbs do it but they should have known enough to suggest that in the first place, so maybe not. If you do it get some help either here or preferably in person.

Well, just as a quick update, I cut a 137 axle down to 131 and then chamfered off the edge a bit with a desktop grinder and it seems alright. I'm thinking about coating the cut off end to prevent some rust, but I'm not really sure yet. I need to get some cone wrenches though since the old axle had locking washer, but that is only a minor inconvenience.