Frame materials

Quoted message said:

Which is the stronger aluminium? 6061 or 7005?

Both. Neither. Either.

It's not just the material, it's what you do with it. 6061 requires heat treatment, a time-consuming
and costly process that (if things are done correctly) ensures a strong frame, typically lightweight
because much of the cost is in the fabrication, not the material, so you might as well make
something nice (as it doesn't add to the cost).

7005 is weird stuff. You can make absolute junk out of it because, if you use enough of it (make it
thick enough) you can get away without heat treating it. This means that, even though the material
itself is considerably more costly than 6061, the end result is a much cheaper frame. Or, you can
use it in very thin tube sections and heat treat it, making a very nice frame. In short, it's all
over the map, and the fact that a frame is built with it tells you virtually nothing. It's *how*
it's built that tells the story.

--Mike-- Chain Reaction Bicycles chainreactionbicycles.comchainreactionbicycles.comOpen ↗

"Jon Morris" <[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

Which is the stronger aluminium? 6061 or 7005?

TIA

"Jon Morris" <[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

Which is the stronger aluminium? 6061 or 7005?

What Mike said. 7005 is probably stronger if it's tempered. In bike applications it's usually not. I
don't remember any Al strength or hardness numbers but you can look 'em up on the web if you care. I
do remember 7075-T6 as being harder than mild steel.

One way it matters is this: If your frame is made out of tempered aluminum it's virtually
unrepairable after it cracks.