How thin can you go on triple clamps?

[posplayr]

expanding cast aluminium by even that small amount will DRASTICALLY weaken it. That is if it doesn't snap or crack anyway before you manage to shoehorn the fork leg in.

I have tweaked a set of welded triples clamps much more than I would have ever thought possible with no ill effects.

The clamps are made to flex, it has to to be able to implement a tightening bolt. So I suspect the metallurgy is substantially more flexible that a piece of simple brittle cast aluminum. Just think about the forces on the triple clamp transmitted from the road, through the tire/wheel and with the leverage it has through a RSU stanchion. The triple can not be inflexible and brittle.

[tkent02]

Are you sure the 1000 triple clamps are wider? I would think that the centers are the same...

Yes, something like 10mm wider. No big deal I guess.

[hampshirehog]

I don't think that forcing the clamps wider is a runner. The circumference would need to increase by 6 mm if I've done the maths correctly and I doubt the bolt holes would line up. When I did mine I just reckoned there was enough meat there to enlarge the holes.

As for can the work be done by your average machine shop, well I did the work myself using a plumbing reaming tool that my old chap had in his garage - no idea what it's called. I never measured how round the holes were and I may have only made them 36mm and a bit wide were, I just test fitted and they weren't far out and you certainly couldn't see air when they were clamped up.

[posplayr]

I don't think that forcing the clamps wider is a runner. The circumference would need to increase by 6 mm if I've done the maths correctly and I doubt the bolt holes would line up. When I did mine I just reckoned there was enough meat there to enlarge the holes.

As for can the work be done by your average machine shop, well I did the work myself using a plumbing reaming tool that my old chap had in his garage - no idea what it's called. I never measured how round the holes were and I may have only made them 36mm and a bit wide were, I just test fitted and they weren't far out and you certainly couldn't see air when they were clamped up.

yes there is a potential alignment issue that might require some adjustment.

Lets say that the diameter of the hole needs to be enlarged by 2 mm, that means that the clamp spacing (at the edge of the tube) needs to enlarge by approximately twice the increase in diameter of 4mm in this case.

Assuming the split was at the center of the clamp opening then you would have a 2 mm deflection on each side, granted that is more than the machine tolerance of the home, but certainly not that much compared to the total deflection you can put on the clamp to close the gap.

In the worst case, you could do something like split the difference, and increase the diameter by 1mm and spread the clamp by 2 mm (1mm per side) to achieve the desired result. I would much rather bend than remove material.

Thoise triples are much more resilient than you might imagine, but stiffness is proportional to the cub of distance so you loose a lot once you start milling.

[Jcgonzal]

expanding cast aluminium by even that small amount will DRASTICALLY weaken it. That is if it doesn't snap or crack anyway before you manage to shoehorn the fork leg in.

I'd have to agree with this. I tried it on a '77 XS750 back in the day, and sure enough I was able to snap the triple tree. It was in the middle of winter in a not so heated garage, which probably contributed to the brittle nature of the material, but nonetheless....