RiddleOfSteel

Hi everyone,

We have some troubling news. A beautiful and venerable MA 2 rim of the high polished variety has developed a partial separation at the pin/weld seam of the rim. I've been working on transferring all Dura Ace to my Masi Nuova Strada and noticed this when I went to get the tire off the rim--I am swapping out the Bontragers (700x32) to old school Michelin tan wall 700x23s. The front is done and looks great. The overall new Campy to old/polished Dura Ace transfer is going well and is looking like it should have been all along, but then this happened. I suspect it's been like this for a little bit...

I am about 210 lbs (6'5"), the spoke tension is in check, I keep 23s inflated to 95-100 psi when riding, and prioritize smooth riding over pounding pavement etc. I'm not hard on things, but this is a vintage wheelset and old things break. And we have a seam separation running the ouer 40% of the brake track surface. The rest of the seam is in great shape.

I suppose my questions are 1) How toast is this? I am currently looking at replacing this 32h example 2) How long, given a non-abusive nature with equipment, would I have, roughly before it really gives it up (I am a bit wait and see) 3) What are some of your experiences with this? 4) Could it be welded successfully and if so, what kind of place would be good to take it?

It's currently super rainy here in Seattle (duh, but more than normal it seems to me), and this is dry bike only kind of stuff, meaning I don't need to ride it soon nor can I really with it being wet outside. This helps the decision-making process. For now, pending feedback, I'm in wait-and-see mode and will inspect it over time (no centuries for this one), and will continue the build. But this sucks to see.

Thank you all in advance for your input and advice. It will be remedied one way or another.

juvela

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No worries; there is a plug in there connecting the two ends.

I would just dress it and leave it.

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verktyg 

I wouldn't worry about that slight separation. I have the same thing in a lot of my rims including other brands.

Those slight separations frequently have a mismatched fit that can cause a bump every time they pass through the brake pads when braking.

I file down the high edge of the separation with a fine tooth flat file. This doesn't work on hard anodized rims so I use a green or gray silicon carbide sharpening stone.

There's some built up aluminum on your sidewalls. This results when the aluminum gets hot enough on the surface and melts a little bit.

I found is that this happens more when the rims are a little wet because grit gets embedded into the rubber brake blocks which creates a lot of friction. You may hear a grinding sound when braking!

I periodically smooth out the rims side walls with Scotch Brite or fine sand paper. I also pull the wheels and dig out any grit embedded into the brake blocks.

I haven't seen any Mavic MA2 rims break at the seams but.. it could happen?

In the early 1970's we saw a lot of Mavic "Demontable" clincher rims fail at the split when the steel pins they used failed. The pins were press fit into the holes in each side of the rims at the joint. See cross section in the picture below.

Mavic changed the design of the extrusions used to make their clincher rims starting with the Module E series. See below.

verktyg

Chas.

RiddleOfSteel

Oh man, this is exceptionally good news! And I now know what pinned means--you would think an image search would help but no...

I did notice the aluminum build up. Sanded it off another set of rims that showed the same thing. Since these are hard anodized, I will look into finding that stone and see how it goes.

Thank you both and have a great Thanksgiving!