Here’s the deal… I do a bit of road riding with some mates and use my old rigid Rockhopper which is currently running on Conti GP 26×1″ slicks. Being very thin these need a lot of pressure and are rated up to 120psi. I run them at over 100psi mounted on Mavic X618 rims (the old jey-core double-eyeletted ones). There’s a sticker on the rims, which I’ve been trying to ignore, that says max 60psi. This wasn’t such a big deal when I was running 1.3″ Sport Contacts at 80psi but the GPs are a different order of magnitude and a fair bit quicker, which is why I use them.

So what’s the worst that could happen? Will the rim fail, and if so how?

And what are the alternatives – is there a 26″ rim that’ll handle higher pressures? Or will 650c roadie wheels fit and will the braking surface of the rims line up with the V-brakes?

Will the rim fail, and if so how?

“possibly” and “in a way that causes maximum injury” respectively would be my view.

Rims never seem to fail gracefully when they split.

This is what troubles me… I figure that a) the double eyelets add a bit of strength to the rims, and b) that manufacturer limits are inherently conservative, however going 2x over them is quite a leap of faith.

Plenty of manufacturers make these tyres, so there must be rims for which they are suitable?

Mavic’s website has this, seems to answer the question!