Jennifer Smith said:I got a question on the difference between Aluminum alloy types.
What are the characteristics of Al 7075 and other types of Al?
i.e. I currently have a handlebar made from Al 7075 & it flexes quite a bit. I have nightmares of
coming down a rocky section of trail and having my Al 7075 bars breaking from the metal
fatigue. Are there better alloys of Al that won't flex so much or am I just paranoid because
my understanding of Al is that it doesn't flex to much & is prone to failure.
In essence, you won't find any aluminum bars built with the same wall thickness that act much
difference. To grossly oversimplify, all the aluminum alloys used in the bike business acts
about the same.
There is a tradeoff between increasing the ultimate shear strength and the ductility (the ability of
the material to stretch without being permanently deformed, more or less). The two goals are
normally at odds with each other - think of it in terms of a fine china plate on one end of the
scale and a frisbee on the other... but with all the "normal alloys" being clumped near the center
of the range.
Quoted message said:Does any know of a good website explaining the different types of Al & their properties?
There are a lot of them out there, but I doubt you'll find one that really digs deep enough to
answer the specific question you're asking. In the end, design, material purity, and quality control
are the things that will keep you out of trouble. The easy answer is to replace your bars every year
with relatively heavy aluminum bars (kind of a brute force insurance policy). Stay away from
ultra-light (aka stupid-lite) bars if you have a flex issue with your current bars.
Mark Hickey Habanero Cycles habcycles.comhabcycles.comOpen ↗ Home of the $695 ti frame
