From what I understood, T6 aluminum has less lithium after heat treating than T8 (I could be wrong).


Anyway, I have been riding with a Marzocchi Z2 Bam fork for the last 11 years with my bike. Just last week the crown cracked while on a ride. This surprised me because the crown was an enormous hunk of metal that showed no signs of fatigue. I think the material was magnesium. I had figured that the bike frame would have gone before the massive crown.

My riding style is fast and technical XC. I never hit drops greater than about 1 foot, but I do ride over logs as thick as 2 feet. Sometimes the large chainring slams very hard into the log or into rocks for that matter. The funny thing is that I have been riding on the original cranks and chainring as well with no breaks.

Does anyone know if there is a way to determine the remaining life span of the bike frame other than just checking it by eye? (x-rays, ultrasound...)