I just picked up a Nishiki tourer with 5-speed 120-spaced rear on which I'm doing a mild resto-mod. The "resto" part is to revert from the clumsy flat bar that was put on it mid-life back to a proper drop (randonneur, if I can find one) bar. The "mod" part is to convert the 5-speed rear to 6-speed. I just bought a new unbranded QR axle from the local co-op. It's 145mm long. Based on other 126mm-ers I have, I need to cut it down to 138mm. There's plenty of threads on each end to allow me to cut just one end and still thread the cones, spacers and locknuts on. But is that "kosher"? The unthreaded part of the axle will be off-center inside the hub, but does that matter? Searching here found only a few references to cutting an axle, one person suggested cutting both ends but didn't provide any context or reason. To me, one cut is better than two. Ideas?

I've only ever cut one end. But I've only removed about 5mm a couple of times.
My only concern would be having enough thread at each end for your particular hub configuration.

Instead of replacing the axle, can you use one of the "Ultra" type 6 speed freewheels with closer cog spacing to fit where a conventional 5 speed does?

[MENTION=9425]madpogue[/MENTION] - Your suggested approach will work fine. I did the same for a 7v configuration with Campagnolo HF hubs from the '70s.

I actually had one of those on a hi-ten 120-spaced frame BITD when they were first introduced. Loved it. Won't work in this case, because my whole objective is to use the existing indexed Accushift downtube shifters. They actually put shifters capable of 6-speed index shifting on this 5-speed setup. The objective of my mod is to take advantage of that now-unused position on the shifter. The idea crossed my mind, but I had to remind myself about the different spacing.

Cool, good to hear fellas. In my case, it's only 7mm, and there are threads a-plenty. Thanks for the assurance.

During lockdown, with nothing better to do, I replaced my steel 7700 Dura Ace rear axle with a titanium one from an XTR hub. I only cut one end (after making sure I'd have enough threads where I needed them to be). Yes, the "blank" unthreaded center section of the axle is not centered. No biggie. I threaded on a nut beyond where I was going to make the cut, so that after making the cut, I could unthread the nut and clean up any boogered threads. I used a file to replicate the chamfer on the uncut end--I doubt anyone could tell that it had been cut.

I’ve cut a few and never had a problem. My only concern has been getting the proper length. I use a hacksaw with two nuts cinched together as a guide, and then briefly clean up the end with a file. (This may leave your axle end sharp!) it’s not fun or efficient, but it works.

Yes, go ahead and cut the axle to the correct length for your frame spacing, then you might have to fiddle with different spacer configurations to get the right O.L.D. with your particular hub.

On a freewheel hub, the NDS should have the shorter spacer/cone/locknut stack, so put the cut end of the axle into the NDS.

Yep, that's my plan.

And to the above, +1, I've had enough experience cutting bolts/studs/etc to know to have a nut threaded on, to assure that it will come off and go back on after the cut/cleanup.

I did this the other day but it was on a track axle , it was coated black oxide . It would not have mattered if I only cut one end but I cut both anyway . The problem was that now I had exposed bare steel , the fix was Brownell's Oxpho-Blue . Use it on anything bare steel . (If you want it black)

A bit late to the discussion, but anyway: if you really don't want to cut an axle and the axle is 10mm x 1mm threading, a 10x1x137mm Shimano Dura-Ace rear axle can be had for about $10 and change from this eBay vendor:

https://www.ebay.com/itm/373266454439

No commercial interest here, but I have bought a few items from the vendor. They seem excellent.

Dunno which is a worse sin in the Campy community, though - modifying a Campy part, or using a Shimano part in a repair. (smile)

Please disregard the strikethru part - I was thinking this was for your CIOCC build, but I see now it's for a different one entirely.

Wheels Mfg sells 137mm 10x1mm QR axles, too. But I've also cut down a few longer axles -- the advice to thread on a nut *before* you cut so that it will clean the threads afterward is well worth doing.

True - but as I recall Wheels wants about $40 each for theirs. I'd rather buy the NOS Dura Ace and pocket the other $30.

No kidding? I paid a lot less than that when I bought one!

No kidding.

https://wheelsmfg.com/axle-01.html

Haven't seen them (Wheels Mfg axles) much cheaper from other sources recently, either.

Gee I wonder if I should thread a nut on before making the cut, so I can.....

KIDDING -- can't believe how many times that admonition was repeated on this thread, mostly _after_ I had mentioned it. Whaddevz. Anyway, it's done. The local co-op had new "loaded" axles, with cones/spacers/washers/locknuts/balls, for $10. Cut was a breeze. I evened up the end and beveled the outside with the side of a cutoff wheel. Had to find the right mish-mash of spacers, locknuts, etc. to get the right spacing. When I spaced it with the freewheel spaced similar to my other 126 bikes, it would have required a LOT more dish. So I tweaked it some more (took advantage of different-thickness locknuts), which was much more favorable wrt dish, and of course, moved the freewheel to the right. Freewheel-to-dropout clearance is... er... close, but it works, and the chainline looks good just eyeballing it.

Still gotta pack the bearings and put the finishing touches on the truing. Thanks, all, for the insights/ideas, I'll def keep that DA axle in mind for future reference.

Epilogue - third time's the charm. Here's the freewheel/chainstay clearance:



IOW, less than the thickness of the locknut. But the chain clears. And yes, I cleaned the freewheel. And the hub. Freewheel shown is a Suntour Alpha 13-30 I bought with a 1989 Hard Rock attached to it. Perfect replacement for the original 14-30 5-speed. Cleaned up fine, shifting on the stand was bang-on, got her on the road, and..... chain skips in the two smallest cogs (13 and 15). So just to confirm it's the freewheel, I threw on a Shimano MF-Z012 (or whatever it's called) 14-28 from my '89 Fuji. No more skip, but I really wanted that 13-tooth small.

Got lucky at the co-op. Found a segregated box of freewheels marked "good quality", and hiding in there was an Accushift Plus 13-32. Slipped 'em an Abe, and shifting is now like buttah, esp. for a freewheel with such a wide range and large jumps between. So now the Hard Rock I bought, primarily for the freewheel, gets its chain-skipping freewheel back. I'm debating just swapping those two small cogs, just because, with a 28 small chainring, I don't really need a 32 (not planning on climbing stairs with it),

Now what to do with that Hard Rock.....

I was going to mention that…

Also good practice to chamfer the cut end.