Magnesium Wheels

[hackers2r]

I just noticed some small damage on the inside of my rear magnesium wheel.  Does this need attention?  It is not deep but the metal is exposed.

It seems like it was done while balancing or mounting a tire because it is on each spoke.  Thanks in advance.

[ducpainter]

I just noticed some small damage on the inside of my rear magnesium wheel.  Does this need attention?  It is not deep but the metal is exposed.

It seems like it was done while balancing or mounting a tire because it is on each spoke.  Thanks in advance.

I'd touch it up and keep an eye on it for corrosion under the paint.

[hackers2r]

Would there be any downside to not touching it up?  I don't know how long it has been like this and it is showing no signs of corrosion.  And could it be touched up with clear fi it needs to be?

[ducpainter]

bare Magnesium will eventually corrode. It will travel under any coating as a white powdery residue. In your case the nicks are small and it will take a while, but it will happen.

Clear will be better than nothing.

I've seen improperly treated mag wheels corrode under paint.

[Speeddog]

Just touch it up with black from a rattlecan.
Shake can, spray some in the cap, and use a small brush.

But before all that, I'd check to make sure it isn't dragging on the brake caliper.

The wheel is tight, yes?
I've seen wheels that were incorrectly installed and they'll get loose and wobble around....

[hackers2r]

Well Speeddog, good call. 

I can't believe I didn't even feel it.  It seems to be barely dragging on the 2 spots as you can see on the caliper.  So, question is, can I sand those 2 spots down in order to solve this issue or is there something else I can check for a solution? 

[Speeddog]

If you've confirmed the wheel is correctly installed and tight, there's some options.

A spacer between the wheel and the hub is the safest.
IIRC, some of the BST carbon wheels needed them, I think MotoWheels had 'em.

If you're handy, not that hard to make.
Or have a fabricator/machinist do it in exchange for money/beer/services.

You can skim a bit off the caliper.
Difficult to tell how much material is there without pulling that piston out of the caliper.

Something I should have said earlier...
Whatever you do to fix the underlying issue, dress down the scraped areas on the spokes so there's no sharp grooves.
No point in giving the wheel an excuse to crack.
Then paint.

[hackers2r]

I've checked the worn wheel areas and there aren't any sharp areas.  There's barely any material missing.  With that said, it'd seem like I would be able to get rid of VERY little on the caliper and solve the problem.  Once I have sanded the caliper down a bit, do I need to redress that as well? Would fine grit sandpaper work well to shave the little bit off the caliper?

[hackers2r]

Also, to confirm it is installed correctly, I'm guessing you mean not wobbling and torqued correctly.  The wheel isn't wobbling as it is evenly worn on all inside spokes and I torqued the wheel myself. 

[hackers2r]

Also, have you seen this before with the Marchesini wheels?  I'm going to confirm rear caliper is tight as well but it just seems strange to me.  I can't believe I wouldn't have felt this dragging.

[Speeddog]

I'd use a file on the caliper, then sand and paint to taste.

I haven't seen it personally on Marchesinis, but heard of clearance issues on BST wheels.

I'd imagine your wheel is intended for a Superbike, those run a smaller rotor, and thus would likely have adequate clearance.

Lots of folks have misadjusted rear brake freeplay, and had the caliper drag until it overheated, burst a hose and caught on fire.
Not as easy to detect as you may think.

[stopintime]

My BSTs came with a spacer, but it would misaligne the wheel so I didn't use it.
Very minor stripes on the wheel clear 'paint'.

There's enough material on the caliper to fix this.

[Duck-Stew]

Looks to me like a stock S2R aluminum wheel which has a Marchesini sticker on it but was cast by Brembo (IIRC).

Address the caliper issue and check to ensure that the 4 wheel locating pins are in the holes and NOT the slots during re-assembly.

[stopintime]

Looks to me like a stock S2R aluminum wheel which has a Marchesini sticker on it but was cast by Brembo (IIRC).
..............

My S2R aluminum wheel doesn't have that rounded thin/flat 'bridge' from one spoke to the next....

[hackers2r]

They are definitely Magnesium wheels.  Held it along with my stock wheel and there was a notable difference even though the magnesium was 6".