Refurbishing M900 Cranks

[ridevintagemtb]

I went the bargain way with a pair not too long ago. Strip the clear an off, and then sand like hell moving from abrasive to fine until all the deep gouges are out. Then I repeated the process with varying degrees of scotchbrite pads (green, maroon, white), and then I polished and applied a decal. Came out pretty nice.

I know he's not all that popular, but here's some solid info on the professional way to do it.

http://www.secondspincycles.com/2012/07 ... shing.html

 

[ridevintagemtb]

I went the bargain way with a pair not too long ago. Strip the clear an off, and then sand like hell moving from abrasive to fine until all the deep gouges are out. Then I repeated the process with varying degrees of scotchbrite pads (green, maroon, white), and then I polished and applied a decal. Came out pretty nice.

I know he's not all that popular, but here's some solid info on the professional way to do it.

http://www.secondspincycles.com/2012/07 ... shing.html

 

[Neilios]

Thanks Mike, good info. Looks like this is the way I'll have to go.

Elbow grease, re-anodising (from reading on here it looks like Acorn is the guy to use), new decals then satin clear lacquer.

I almost need a basket case crank to practice on...

Cheers,

Neil.

 

[66 triumph daytona]

Re:

I refurbed a set of M900 cranks last year and used tinfoil dipped in water as an abrasive,it worked out brilliantly.Give it a go but top tip-wear disposable gloves as its very messy.

 

[Thias]

Just to clarify. The M900 cranks are not painted at all. Just a very hard and thick layer of anodizing. It is so thick that it chips away (if they were neglected for a looong time) and gives the impression of laquer. But its not.

Imho paint (even clear) on any crank is not a good idea. It gets worn off very fast.
If you polish you cranks and don't want to spend the money on anodizing, just leave them bare and use automotive wax product to protect the finish. You can then always come back and repolish them if necessary.

 

[Neilios]

Thanks Thias and Triumph

Thias, that's good info, if that's the way they were then that's what I'll do. You 100% sure?

Cheers,

Neil.

 

[Thias]

Yes I am. But be aware that leaving them bare will of course not be anywhere near as durable as the original anodised finish. Shimano knew what they were doing there

 

[Neilios]

Oh yeah of course they did!

I spoke to Acorn, they don't do cranks anymore, something about hydrogenation of the alloy during stripping. Any other suggestions, other than inventing a time machine and going back to 1992?!

 

[mkozaczek]

My experience having done almost 40 pairs of these is that were in fact clear coated over the anodizing, you can remove it by solvent which you can't do to anodizing. I opted for clear powder coat not lacquer. I would agree that you should not use liquid paint as it will scuff on the first heel rub.

Also you can't anodize something thick, it's anodize which is a molecular change to the base metal and not a coating per se so thickness is at most around 5 mils but thats into the base metal and not a build up on top of it.

Also, any anodizing process would destroy the logo which is found on the M900 cranks.

So once again, if you want a factory finish it takes, stripping the old anodizing, polishing, clear anodizing, applying a high temp transfer decal and then applying a clear powder coat layer.

 

[syncrosfan]

What Martin just said... as far as restoring original finish.
I did sand and polish a set of M900 cranks not too long ago. An had them clear anodized afterwards. The interesting part is: when you polish the to a super high sheen they look more like chromed, but after the clear anodizing they get the more satin finish that one sees on NOS cranks. The tricky part (almost impossible) to duplicate is the XTR logo on them. Stickers won't cut it. Eventually a found a NOS pair of those cranks (for a decent enough price) and I gave up on project M900 refurb.