Can Alu frames ever feel like Steel frames?

[pileyk]

I'm talking regular fully rigid normal/hybrid bikes, not the extremes of MTB or road bikes. I've read people claiming that frame material itself does not affect stiffness rather how the tubing is selected and put together, etc. By their logic the saying is that ALU is lighter than STEEL for a given stiffness, i.e if you wanted a steel bike as stiff as alu then it would be much heavier.

But the few alu bikes I've ridden (with no susp) all feel horrible and harsh with vibrations on rough terrain vs steel. So if it's not the frame material causing it, why can't manufacturer build an aluminum frame that way less stiff, similar to steel (even if it's more "noodley") that has the same comfort but it just lighter??! Most people who aren't riding serious would prefer an absorbent comfier ride at the expense of some flex surely...

Do such frames exist? I'm 200lbs so it can't be too delicately built but it annoys me when folks say "it's not the frame material" or "alu can be just as smooth riding as steel" because in my (limited) experience all alu frames so far feel quite harsh in comparison! If it was possible to make them less stiff with same flex as steel but just lighter, then surely that would be a very popular thing to sell.... Thoughts?

 

[winjohn]

I have also read that it is not the frame material alone that affects the ride quality. IMHO the Cannondale CAAD frames seem to have a very pleasant ride quality.

John

 

[BiketoBasics]

Someone once suggested the analogy between steel and aluminum (or, Al-You-Min-Ium as the Brits say) frames is like the difference in feel between batting with an Ash tree bat or an aluminum bat in baseball. I always seek out steel frames. An aluminum frame might ride nicely if it was designed properly, had a long wheelbase and could fit large diameter tires.

 

[hamster]

The stiffness issue is that indeed you could make an alu frame as flexy as a steel one - the problem is the different fatigue characteristics. Aluminium is entirely unlike steel in that it has a finite fatigue life regardless of the load. Steel has a limit below which it is effectively infinite. As a result a nice flexy alu frame will have a short life. To engineer them for acceptable durability they ended up as stiff as jackhammers, unlike steel frames.