Hub spacing question

[mike_eb]

My Vitus has 126mm hubs, is it possible to fit a 130mm hub after removing 2mm of spacers each side to fit the dropouts?

I do not want to flex the stays due to it being glued together!

 

[dbmtb]

Doubt it.

Cut the axle down to be sure.

 

[hamster]

It depends a lot on how tight your frame is - if it's a loose 126 then go for it.

There was a similar discussion on the CTC forum a week or two back. The consensus from Chris Juden (CTC tech officer and chartered engineer) is that it's OK on ALu frames, and they will spring back. Fitting the wheel will be a bit of a pain, but OK.

 

[perry]

dont do that the dropouts need to be parallel to hold correctly and just pulling the stays open to force the wheel in is appalling form and places stress on the welds . there are ways to cold set a steel frame and that isnt it

if its cup and cone look for a shorter axle and change that as long as there is space for the cassette/freewheel

 

[lelobysfoot]

hubs

This is an alu bonded frame and its maybe best not to. I've done a couple of hubs for guys wanting to run 10sp in 126mm frames and there are plenty available that you can do a DIY fix on the non-drive side allowing enough dish to give a decent enough strength in the wheel.
American Classic, Dura Ace 7900, Ambrosio, Tune, etc. You can even get a Powertap in there too.
The drive side needs left as it is of course.

 

[mike_eb]

I completely agree about not stretching the rear triangle.

My thought is if I remove 2mm of the spacer washers from each side of the hub the spacing will then be 126. Is this correct?

 

[lelobysfoot]

hubs

Technically yes, but your chain might hit the dropout on the drive side :cry:

Only remove the spacers on the left if you can.
Cheers.

 

[terryhfs]

I've tried both in the past. Cold setting using threaded rod, washers and nuts, and axle shortening.

2mm over the length of a chainstay will not put the dropout faces badly out of alignment in my experience. I'm not sure that a 2mm deflection puts any more strain on the welds/brazes than a 14st bloke sitting on the saddle does, and my steel frame deflects more than 2mm just by me grunting up hills on it.

Messing with axles always seems to end in tears though. You take spacers out equally on each side and find that the small sprocket eats the frame. You take them all out of the non-drive side and find that the Q/R won't do up and even when it does the tyre is rubbing the front of the chainstay and the brakes are less than happy.

 

[lelobysfoot]

hub

You'll be fine with a re-dish and a road-specific quick-release. I wouldn't recommend a 4mm stretch on a Vitus frame.

 

[GarethPJ]

Whether or not the aluminium alloy could take cold setting would depend on the particular alloy in use and the heat treatment. And then there's the bonding, quite how that would take to the cold setting is anybody's guess. It's not something I'd try. Given the short fatigue life of most aluminium alloys it is certainly a one way trip. If you are going to cold set the frame do not try simply forcing the ends apart. If the two sides are not symetrical then one side will give more than the other and you'll end up with your rear end out of line (a nasty complaint). Do one side at a time. The traditional way is to use a hefty timber braced against the seat tube. Do it a little at a time until your spacing is 128mm, then repeat on the other side until you get 130mm. That way your allignment will be correct.

Removing spacers will of course depend on whether there are any spacers at all. Some rear wheels have a single large spacer that would need to be machined down accurately. Some have no spacers at all.

And don't forget that you would also have to remove 4mm from the axle.