Discovering a bent axle
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Discovering a bent axle - replacement source?
Restoring a wheel from a '78 Schwinn Superior. Normandy QR high-flange hub, Weinmann non-box rim. So I have the wheel in the truing stand and I'm approximating dish using the stand. I switch back and forth and notice that things aren't consistent. Then I note that when I rotate the axle in the stand, the rim moves left or right about 2mm. In a completely rookie move, I forgot to check if the axle was straight.
The locknut to locknut spacing is 126mm (rear wheel, obviously). QR axles. About 3mm protrusion from each side, so 132mm axle length. If I want with 5.5-6mm/side, I'd get ~137mm length. So: words of wisdom regarding length? And what is the best source? I'll measure, but I suspect that these are 10mmx1mm thread pitch. Wheels Mfg has some 137mm ones, but they're 20 bucks. Is that my best source?
I was only approximating dish with the stand, but my dishing tool shows that I was within about 0.2mm. But I want to have a good axle.
Thanks.
The locknut to locknut spacing is 126mm (rear wheel, obviously). QR axles. About 3mm protrusion from each side, so 132mm axle length. If I want with 5.5-6mm/side, I'd get ~137mm length. So: words of wisdom regarding length? And what is the best source? I'll measure, but I suspect that these are 10mmx1mm thread pitch. Wheels Mfg has some 137mm ones, but they're 20 bucks. Is that my best source?
I was only approximating dish with the stand, but my dishing tool shows that I was within about 0.2mm. But I want to have a good axle.
Thanks.
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Just looked - yes, much cheaper. I'm taking it if I buy close (e.g. 141mm) I just saw off 5 or so mm get to 136, then dress the cut with a file and chase the threads.
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That will work. The general rule for QR axles is: length= dropout spacing + 11 mm. So, for a 126 mm spacing the axle should be 137 mm, for 130 mm spacing it should be 141 mm and for 135 mm its 146 mm. Shortening a too long axle is easy but be sure the threading is long enough to allow the cones to thread on enough to allow bearing adjustment.
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Thanks, HillRider. The axle that's on there now is only about 3mm on each side, so width + 6mm. Sheldon suggests that that's adequate esp. if you have a 120mm originally, and pop it out to 126mm, so as to use the original axle. Not sure why you'd want to use the original axle, but Sheldon said it could be done. Frankly, though, I want to have the extra 2.5-3mm so that the seating is ample.
Not that axle wear matters: this is a 41 YO bike and I don't expect to be here when it hits 82. But should be nice to know it's well set up for whomever rides it in the future.
Next step, after the wheels, is to clean up the frame and parts, and to install new cables and housings. I'd repaint it, but it has a really cool League of American Wheelmen sticker on the frame. Too interesting to paint over!
Not that axle wear matters: this is a 41 YO bike and I don't expect to be here when it hits 82. But should be nice to know it's well set up for whomever rides it in the future.
Next step, after the wheels, is to clean up the frame and parts, and to install new cables and housings. I'd repaint it, but it has a really cool League of American Wheelmen sticker on the frame. Too interesting to paint over!
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Yeah, that 3 mm or so per side is adequate. I've converted 126 mm hubs to 130 mm by adding 4 mm of spacers to the NDS and reusing the original 137 mm axle leaving 3.5 mm per side. It worked fine. However, If I had to replace the axle, I would buy the "correct " length.
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Axle bending is pretty common with freewheel hubs, and the forces that bend the axle are greater the more the axle end moves away from the RH bearing.
Also there's a relationship between the axle and drop out and what happens to one often transfers to something with the other. In this case a check of the drop outs being parallel to each other is a good idea. While one can make crude drop out alignment gages proper ones are much better. Andy
Also there's a relationship between the axle and drop out and what happens to one often transfers to something with the other. In this case a check of the drop outs being parallel to each other is a good idea. While one can make crude drop out alignment gages proper ones are much better. Andy
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Thanks Andy. SWMBO has decreed that due to recent expenses (new roof, gutters, and Hardie-plank siding on Chez Wizard) we must mind our BRP (bicycle related purchases). So, while I'm jonesin' for a set of the Park Frame and Fork Dropout Alignment Gauges, I'll have to get by with home-spun using the 3/8" all-thread and some pipe that's in the dungeon of Castle Wizardo.
BTW, you probably knew this but I'll throw this out for others. I discovered that putting a wheel in the truing stand and then rotating the axle (with the wheel not rotating) is an exceptionally sensitive test for a bent axle. Given a bead seat diameter of 622 or 630, we get a radius of 311-315mm. IF we assume the bend is at the DS spacer inboard point, about 25 mm from the dropout, this means we have a 126/2 - 25, or 37mm distances from center to the bend. This means that a 1mm variation in rim position when one rotates the axle translates into a somewhere between a 1mm * 37/315, or 0.1 mm out of round variation in the axle. And you can do this without removing the axle from the hub. This may be a big "duh" for others, but it was useful to me.
BTW, you probably knew this but I'll throw this out for others. I discovered that putting a wheel in the truing stand and then rotating the axle (with the wheel not rotating) is an exceptionally sensitive test for a bent axle. Given a bead seat diameter of 622 or 630, we get a radius of 311-315mm. IF we assume the bend is at the DS spacer inboard point, about 25 mm from the dropout, this means we have a 126/2 - 25, or 37mm distances from center to the bend. This means that a 1mm variation in rim position when one rotates the axle translates into a somewhere between a 1mm * 37/315, or 0.1 mm out of round variation in the axle. And you can do this without removing the axle from the hub. This may be a big "duh" for others, but it was useful to me.
Last edited by WizardOfBoz; 08-06-19 at 03:05 PM.
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Wiz,
I have pulled two Helicomatic hubs out of wheels this week, and they are both laying on the bench. 130mm axle length and complete with cones bearings and nuts. The innerds should work on your hub. If you want them for the shipping (I think $7 would cover it) send me a PM and I'll send them to ya. Smiles, MH
BTW, I won't have to check with the War Department before doing so, Har! MH
I have pulled two Helicomatic hubs out of wheels this week, and they are both laying on the bench. 130mm axle length and complete with cones bearings and nuts. The innerds should work on your hub. If you want them for the shipping (I think $7 would cover it) send me a PM and I'll send them to ya. Smiles, MH
BTW, I won't have to check with the War Department before doing so, Har! MH
Last edited by Mad Honk; 08-06-19 at 06:38 PM.
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Thanks, Mad Honk, but I need 137mm or so. What happened to the Helicomatic hubs? Them hubs had some serious machining wizardry.
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Wiz,
Measured both this morning and one is in that 137 range. You want it? gimme a call 812-336-3283 Smiles, MH
Measured both this morning and one is in that 137 range. You want it? gimme a call 812-336-3283 Smiles, MH
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Thanks, HillRider. The axle that's on there now is only about 3mm on each side, so width + 6mm. Sheldon suggests that that's adequate esp. if you have a 120mm originally, and pop it out to 126mm, so as to use the original axle. Not sure why you'd want to use the original axle, but Sheldon said it could be done. Frankly, though, I want to have the extra 2.5-3mm so that the seating is ample.
The trick with QR axles is that that the axle can't protrude beyond the dropout AT ALL. If it does, the QR will bottom against the axle rather than clamp tight against the dropout.
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Ordered a Wheels Manufacturing 137mm 10mm x 1mm axle. Hopefully I don't have a screwball 26tpi axle on this Schwinn.
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Sorry, I missed your second post. I ordered a fancy Wheels Mfg axle. Their list price was 20.90, and some yahoo in my native Wisconsin offered the thing for 20.89. This guy's ebay name is "affordable parts sales". I thought that the 1 cent discount was an amusing way for them to be "affordable"!
This was way more expensive than some of the eBay offerings and your offering. At the same time, the bend in the current axle is pretty slight so I'm kind of engineering overoptimizing.
I rebuilt the wheels on the Superior. I'm gonna report the results in the thread on that topic. Bottom line: rides great. Really comfortable.
Jim