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-   -   130mm Frame Spacing vs 135mm rear hub? (https://www.bikeforums.net/bicycle-mechanics/395766-130mm-frame-spacing-vs-135mm-rear-hub.html)

werdna2012 03-09-08 05:11 PM

130mm Frame Spacing vs 135mm rear hub?
 
I have a nashbar aluminum road frame with 130mm rear spacing. I was wondering if anyone knew if a 135mm rear hub would work with this frame? I know that sounds kind of stupid, 130mm hubs probably exist for a reason, but why wouldn't a 135mm hub work? I know it will fit, I can fairly easily get 5mm of extra spacing between the stays, but will this damage the hub overtime, because of the extra pressure, etc. . . ? The reason is, I'm building a single speed 29er for road use and I wanted to be able to swap the wheelset between my road frame setup and the 29er. Any help on this would be great, thanks!

operator 03-09-08 05:13 PM

5mm is too much. Respace, or get a 130 wheel.

AEO 03-09-08 05:32 PM

you can always add 2.5mm spacers to each side of a 130mm hub wheel.
spreading aluminum frames can result in a catastrophic failure causing severe injury or worse, death.

revolator 03-09-08 05:37 PM

Sheldon Brown would say either get a new frame (135mm spacing) or get new wheels.

jaxgtr 03-09-08 05:37 PM

moving to mechanics

Bill Kapaun 03-09-08 06:00 PM

You could probably remove 5MM worth of spacers from the NDS and dish the wheel to re-center it.
IF you have a QR axle, you would have to replace it with a 5MM shorter one.
You didn't say what hub you have, but a lot of Shimano 135's have a 8 & 3 MM spacer on the NDS. You could remove the 8 and add another 3.

HillRider 03-09-08 06:21 PM


Originally Posted by AEO (Post 6309899)
you can always add 2.5mm spacers to each side of a 130mm hub wheel.
spreading aluminum frames can result in a catastrophic failure causing severe injury or worse, death.

The OP doesn't need to ADD spacers, he need to remove them.

And spreading a 130 mm Al frame by springing it with your thumbs to accept a 135 mm hub is ok even if it makes wheel removal and replacement a bit of a hassle. You don't want to "cold set" it permanently the way you can with a steel frame.

operator 03-09-08 06:25 PM


Originally Posted by HillRider (Post 6310230)
The OP doesn't need to ADD spacers, he need to remove them.

And spreading a 130 mm Al frame by springing it with your thumbs to accept a 135 mm hub is ok even if it makes wheel removal and replacement a bit of a hassle. You don't want to "cold set" it permanently the way you can with a steel frame.

If he doesn't have the hub/wheelset yet, it'd be wise not to buy into the problem. Unless the wheel can be easily unspaced.

HillRider 03-09-08 06:33 PM


Originally Posted by operator (Post 6310268)
If he doesn't have the hub/wheelset yet, it'd be wise not to buy into the problem. Unless the wheel can be easily unspaced.

+1. Why make extra work?

BTW, to the OP: If you already have the 135 mm hub, you don't have to buy a new axle if you respace it to 130mm. Axles cut easily with a hacksaw and shorening it 5 mm is quite straightforward.

AEO 03-09-08 06:36 PM

I figured the OP wanted a wheelset he could use in both 130 and 135 spaced frames.

saturnhr 03-10-08 12:41 AM

1 Attachment(s)

Originally Posted by AEO (Post 6309899)
you can always add 2.5mm spacers to each side of a 130mm hub wheel.
spreading aluminum frames can result in a catastrophic failure causing severe injury or worse, death.

I know it is not the official party line and I am not formally promoting it, but I have spread a 6000 aluminum series bmx fame (originally 110mm spacing) to 130mm successfully (which is quite substantial considering the short chain stays). The purpose was building a small kid's road race bike accommodating a 9speed cassette). I used a threaded rod with nut and washers as a spreader. I think 7000 series aluminum is harder and more bridle and might not have allowed such widening. :)
saturnhr

werdna2012 03-10-08 01:16 PM


Originally Posted by HillRider (Post 6310230)
The OP doesn't need to ADD spacers, he need to remove them.

And spreading a 130 mm Al frame by springing it with your thumbs to accept a 135 mm hub is ok even if it makes wheel removal and replacement a bit of a hassle. You don't want to "cold set" it permanently the way you can with a steel frame.

Thanks for the insight. I guess I'll just give it a shot and see what happens, I know it'll fit so. . . Definitely not going to attempt a cold set with the aluminum though; very risky.

well biked 03-10-08 01:21 PM

FWIW, there are aluminum frames that come with "in between" spacing, like 132.5mm, so that more than one size hub can be used. I've also heard of folks using older 126mm spaced Cannondales with 130mm hubs with no problems. As already pointed out, this is isn't cold setting, just simply flexing the stays apart by hand when you install the wheel.

barba 03-10-08 01:26 PM


Originally Posted by saturnhr (Post 6312356)
I know it is not the official party line and I am not formally promoting it, but I have spread a 6000 aluminum series bmx fame (originally 110mm spacing) to 130mm successfully (which is quite substantial considering the short chain stays). The purpose was building a small kid's road race bike accommodating a 9speed cassette). I used a threaded rod with nut and washers as a spreader. I think 7000 series aluminum is harder and more bridle and might not have allowed such widening. :)
saturnhr

I would NOT let my kid ride that frame. 20mm with an aluminum frame is asking for trouble. It may not have failed immediately, but that does not mean that there is no damage.

well biked 03-10-08 01:35 PM


Originally Posted by barba (Post 6315321)
I would NOT let my kid ride that frame. 20mm with an aluminum frame is asking for trouble. It may not have failed immediately, but that does not mean that there is no damage.

+1

saturnhr 03-10-08 05:12 PM

I acknowledge the fact that the general party line opinion in bicycle mechanics is that aluminum frames cannot be cold formed and I see that my opinion represents a challenging thought, if established authorities like our beloved Sheldon Brown and Leonard Zinn say: don't do it.
However, my contra-thesis is that their opinion is not evidence based. A quick Google search for “aluminum bending” shows a lot of examples and instructions of aluminum tube bending. I like to suggest the following: 6000 series aluminum can be bend and cold formed if done cautiously, cannot be done by hand, and needs special (easily (made) rods and frames to apply forces in a controlled fashion. Applying forces with threaded rods is an easy way to do it. The little bridge between the chain stays automatically protects the bottom bracket chain stay welds.
From own experience with bicycles and aluminum bending and cold forming for other issues I actually believe that aluminum can be easier cold formed than steel, since it is less springy. To due its elasticity steel distributes the bending forces automatically more evenly over the work piece, with aluminum precaution only has to be made that bending doesn’t occur to much at one site only.
In the bicycle project pictured above I also had to bend the dropout back inward to compensate for the chain stay spread. With correcting the dropout it is important to avoid too much bending at the welds (chain stay to dropouts)
The strength of the rear bicycle is dominantly determined by the linked triangle of chain stay, seat stay, downtube and the rear axle linking of those to each other. As long as nothing cracks (which with the above precautions will not occur) plenty enough of strength remains.
So now all you fellow forum members are welcome to scream and object and so more you do the easier it will be for me to show my children later, that I was the first to resolve the (what I think) unsubstantiated claim. Anybody following those easy guidelines above will easily agree with me. :)

Grand Bois 03-10-08 08:51 PM

I've always wondered why it's perfectly acceptable to toe in brakepads to prevent squealing by bending the aluminum caliper arms, but to cold set an aluminum rear triangle is to invite catastophic failure.

HillRider 03-11-08 10:57 AM

While I have always repeated the party line that Al frames should never be cold set, I've also wondered why it was such a blanket prohibition. I can certainly see why bonded (read glued) frames like the late '80's to early 90's Treks should not be subjected to the stress, I've never understood why welded Al wouldn't be suitable. After all, Cannondale aligns their welded Al frames by cold setting them after heat treating.


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