Put it in the freezer and it bends back?

[dunawan]

My next-door neighboor was telling me about this bicycle rim. He said he couldnt remember the name but apparently if it were to bend, you just place it in the freezer for how ever long the instructions say and the rim supposidly bends back. Is this true? Is there such a thing?

[ivan]

I think it is possible. It's called metal memory(or something). Although, there are probably man limitations to that, e.g. a point after which it won't bend back properly, time it takes to bend(better finish off your ice-cream) and the price of the rim.

Seems like a good idea, though. I'd like to hear more about it.

[puresyn]

Yes, the old Z rims, fiberglass rims used to do that. Mag wheels will do it too.

[wickedbob]

Yeah them have metals you just dip in boiling water and they go back to their shape. People thought of making cars like this just dump boiling water one and go!

[Racenut]

Originally Posted by puresyn

Yes, the old Z rims, fiberglass rims used to do that. Mag wheels will do it too.

Yep, I remember those. Friend of mine had Z-Rims. We thought they were the coolest thing ever. He could put his bike in the bike rack and lean it over till the handlebar touched the ground. The rim would just flex back. They were light weight too.

Seems like they would suck on a uni though

[onelesscar]

Originally Posted by puresyn

Yes, the old Z rims, fiberglass rims used to do that. Mag wheels will do it too.

Fiberglass and mag do this? I'm surprised, first of all, that you can even make a decent wheel out of fiberglass, and second, that fiberglass would bend enough before breaking to make this even feasible.

The only materials that I'm aware of that have this "memory feature" are Nitinol and one or two copper alloys. However, I'm not sure how suitable any of these metals would be for rims, as materials that exhibit this memory feature tend to also be superelastic, making for a flimsy rim.

[onelesscar]

I was looking into Z-rims, and here's what one guy said:

"ACS Z-Wheels were a popular type of wheel for the professionals. All colors with matching hubs. There was a rumor that if you placed them in the Freezer they would straighten out. From the experiences of my friends this didn't really work. But they did make nice decorations to the pile of old broken bike parts in my garage. Unfortunately they faded away quickly. Brakes wouldn't work well with them."

However, he also said that they were made out of DuPont Zytel...which as far as I can tell is a plastic, not any sort of metal.

[señor coolguy]

Originally Posted by Racenut

We thought they were the coolest thing ever.

hehe, good one