We used to make them (aluminum axles) for the F9R, H1R
and H2R bikes. AMA rules said swing arm pivot bolts and axles had to be
magnetic, so, we just pressed in a slug of steel, about 3/8ths of a inch into
the ends of the axle, instant sneaky legal.
Titanium is best, but 7075-T651 isn't bad as an axle/swing arm pivot shaft bolt/steering head stem.
I ain't speaking about perfect condition bikes and
courses, but bikes that didn't have the steering stems or swing arm bolts taken
out for most of the year, run on places like Cotati, that still had weed filled
bomb craters on it, the Isle of Man, with fall offs all over the place, lots of
uneven pavement, and other toilets of race courses, some even street circuits
like Miami used to be. .
Also, same stuff was in my 23 year run, until stolen, STREET H2(R). The one that never had the pivot bolt or stem out of it, until, I assume, it was parted out by the thieves, or the front/rear axles either.
This stuff was also in other bikes, like Nortons, Honda CR750's, Suzuki TR750's, a herd of Yamahas, a whole bunch of other racing stuff, so...what's the problem? I don't see one if the parts are made of good stuff and correctly.