135mm OLN hub in a 130mm alloy frame?

[Bonefishblues]

Just a quick question prompted by a discussion on another forum.

I wouldn't have any qualms about springing an alloy frame 2.5mm per side, as it were to fit an mtb hub in a road/hybrid frame.

Am I right/wrong/depends?

[Brucey]

no thanks

cheers

[Bonefishblues]

Go on, give me more please

[The utility cyclist]

no thanks

cheers

A mass produced bike by Specialized - Globe series both men and ladies variants, it's never been an issue, 10+ years under heavy use quite literally in the sense personally and I've never heard a dickie bird re the 135mm Deore hub being problematic in the 130mm dropouts!

You do seem to be a proper doom and gloom merchant using anecdotal 'evidence' for your viewpoint, I'm guessing your bike shop had (another) recent failure that you made it your business to know about right?

[Vorpal]

In general, I should think it would be okay, though it somewhat depends upon the alloy. If by 'alloy' you mean aluminium, it will reduce the life.

[Cyril Haearn]

There is a lot on here about springing or setting frames (steel?)
Is alloy different? What about carbon?

[Bonefishblues]

There is a lot on here about springing or setting frames (steel?)
Is alloy different? What about carbon?

The reason I ask is because it is - I'm no metallurgist, but do know that aluminium alloy is very different to steel in its inability to accept repeated bending without fracture, which is what prompted the question.

[Bonefishblues]

What I absolutely wouldn't seek to do is re-set an aluminium alloy frame.

[Brucey]

frames crack by fatigue because in use, they see an alternating stress. If you 'spring' a frame then you increase the mean stress, and as the plot above suggests, the tolerance for cyclic stresses is reduced whenever you do this, i.e. the frame is more likely to break via fatigue.

Steel frames can usually be cold-set to a new dimension but aluminium frames usually cannot, not without a significant risk of damage, anyway.

cheers

[Bonefishblues]

Can you explain what I'm seeing here?

What's in my mind is that a one-off flexation which is then locked in place and cannot then move/flex is very different to say a badly-specced tubeset (the Vitus 979 one spring (arf!) to mind) where constant flexing is taking place.

Am I misreading?

[Vorpal]

Can you explain what I'm seeing here?

What's in my mind is that a one-off flexation which is then locked in place and cannot then move/flex is very different to say a badly-specced tubeset (the Vitus 979 one spring (arf!) to mind) where constant flexing is taking place.

Am I misreading?

But when you force it further open, you increase the stresses in the rear triangle. The variable stresses, which occur naturally in use are on top of that.

[Bonefishblues]

Can you explain what I'm seeing here?

What's in my mind is that a one-off flexation which is then locked in place and cannot then move/flex is very different to say a badly-specced tubeset (the Vitus 979 one spring (arf!) to mind) where constant flexing is taking place.

Am I misreading?

But when you force it further open, you increase the stresses in the rear triangle. The variable stresses, which occur naturally in use are on top of that.

Yes, I get that, but then I lock it in position with the QR and an axle, and little or no deflection occurs thereafter, shirley?

[fastpedaller]

Can you explain what I'm seeing here?

What's in my mind is that a one-off flexation which is then locked in place and cannot then move/flex is very different to say a badly-specced tubeset (the Vitus 979 one spring (arf!) to mind) where constant flexing is taking place.

Am I misreading?

But when you force it further open, you increase the stresses in the rear triangle. The variable stresses, which occur naturally in use are on top of that.

Yes, I get that, but then I lock it in position with the QR and an axle, and little or no deflection occurs thereafter, shirley?

But when you do that the dropouts won't be parallel any more (assuming they were parallel at 130 - however this may be somewhat mitigated by the steel locknuts of the axle eating into the alloy dropouts.

[Bonefishblues]

But when you force it further open, you increase the stresses in the rear triangle. The variable stresses, which occur naturally in use are on top of that.

Yes, I get that, but then I lock it in position with the QR and an axle, and little or no deflection occurs thereafter, shirley?

But when you do that the dropouts won't be parallel any more (assuming they were parallel at 130 - however this may be somewhat mitigated by the steel locknuts of the axle eating into the alloy dropouts.

Understand. But what will be the effect of doing that on the frame and its longevity?

We have a member who has done it for 10 years in a frame. What has he missed in terms of risk?

[iandriver]

When faced with this, the dropouts actually measured 132mm. The LX hub had two 2.5mm spacers. One removed, chop down axle, quick redish and one 132.5 hub in a 132mm space. First place I'd start would be to have a measure up, find out what you are really dealing with, go from there.