I've had a set of these polished up all shiny like and then clear powdercoated, they look lovely! Only problem is that the powdercoat scratches quite easily, so I'm thinking about stripping this off and leaving the metal bare, polishing it occasionally as need be. But, will the bare metal oxidise/rust? Does anyone know?

cheers 🙂

I've done it to some LXs. They dull a bit, but otherwise they're fine. A Brillo pad brings them up shiny again. 🙂

aluminium alloy – will corrode.

Helicopter tape them when new?

Cheese.

Magic

aluminium alloy – will corrode.

Does metal polish provide a barrier to help prevent this?

A Brillo pad brings them up shiny again.

I've had them professionally polished, they look ace, would really like to keep the finish. I suspect a brillo pad would detract from the current mirror like state 🙂

Careful how much polishing you do.A bit of shoe rub wore a hole in the drive side arm on mine!The material is wafer thin on the outside of the arms

Does metal polish provide a barrier to help prevent this?

AFAIK metal polish cleans and sands the metal finely – so no.

Decent UV-resistant laquer from a rattle can.

XT HTII crankarms – what are they made of?

Crappite. Thats what they are made of. Wheras XTR are made of costalotium.

Never seen my old XT crank arms with a think oxide on them in the worn bits unlike the insides of rims for example – I guess they use a resistant metal alloy (Polymetal alloy – say Arnie 😉 )?

Bogies?

You'd want to coat them I think. I'd not want to polish them, they're thin enough as it is.

Polished / buffed aluminium alloy will suffer from increased potential for crack propagation, than a shot blasted surface.

Polished / buffed aluminium alloy will suffer from increased potential for crack propagation

Apart from the fact that you have to do material removal to polish to a shine (removing the surface compression that comes with the shot-blasting and helps with crack prop). Seeing as people have actually worn through the arm outer, I'd be steering clear of material removal!

aluminium will always oxidise unless you use a grade like 2000,

as the owner of 2,!!! yes 2 pairs of xtr cranks i can confirm they are in fact made of a mix of Crappite and costalotium, all woven round papermache and lovingly finished with some cheese spread,

not really they are duralium, which is a cheese spread from from spain, i think they export it to japan, where is then sold on to shimano as a metal paste?

i have noticed that you feet don't even need to touch the outer arm to remove the finish on these, i think just the suggestion is enough to scour the arms.. 😐

I get the impression that a few of the posters on here would rather carry their mtb over/around a muddle rather than ride through it.