Forks...aluminum Vrs Steel

[ridgrunr]

Seems most if not all of the manufacturers are going to aluminum fork tubes. The lower ends have been aluminum for years, but they haven't been the part doing the sliding and contending with friction.

So I wonder if this is another "new and improved gimick" for them to announce that their bikes have a new inovation (like the upside down forks of the 90's...remember them?) or if the aluminum forks sliders really are better than the steel units?

Aluminum parts that move have less unsprung weight than heavier steel counterparts. Wheels and rear swingarms come to mind.

And aluminum is stiffer than steel, with almost no flex and it has no memory, so if it bends or flexes it stays bent. So in many applications, not much is gained by aluminum. Take frames for instance. Beta and Montesa use them, but the other makers don't and usually the aluminum fames have to be physically larger to get the same strength as steel tubing, but they end up being very close in weight anyway.

Aluminum is much softer too. I'd have to think that they'd have to be thicker tubing than their steel counterparts to be as strong, and then be coated with a very hard material to keep them from wearing out in a year like the cylinders of a 1970 Chevy Vega. So are they really lighter? Are we going to see curved forks on most bikes after a year of use?

So are there any real advantages to aluminum fork sliders?

[ridgrunr]

After doing a little investigation it seems the diameter of the aluminum forks are 40mm while the steel forks are 38mm.

[copemech]

I think they saved a pound or so with the 40mm Marzocci fork on the gasser.

Some alloys are very strong and springy. Take your skidplates for example. Stress risers and cracking are another issue!