Classic & Vintage - Odd stress marks on old anodized rims

I'm posting this here since the mechanics forum FAQ reminded me C&V might have more direct first-hand experience with my issue.

I've dusted off my old road bike and am currently cleaning the second pair of wheels i have. These are Wolber Super Champion Aspen tubular rims i built and raced myself back in the early 80s. DT 15 spokes, ofmega hubs. I'm noticing lighter colored discoloration at each spoke area, just on the sidewalls, on both sides of each rim. I don't recall seeing them back when i used them and they've been stored in garages since i last wore them back in the late 80s. The spokes do not seem overly tight at all by feel, though i do not have a tension meter. Also, it's only a discoloration. There is no bump i can feel at these marks at all, it's just a visual clue. is this just something that happens to hard anodized rims over time? in your experience, is there cause for concern in the rims' structural integrity?

see the attached jpeg. thanks for any input.

292183

eric
fresno, ca.

A lot of lightweight rims from back then seem to "suffer" from this where the sidewalls tend to deflect slightly with the tension from the spokes so that the dark anodizing would wear off at these slightly bulged out areas on the rim. Eventually you will have two tone sidewalls with alternating dark and light areas where the anodizing had worn off. Very common to see on wheelset with very light rims like Mavic's GEL280 and to some extent, their 330GLs too.
I would say, don't worry about it....

Chombi

Don't worry, just ride.

They are fine.

I've got some Tom Ritchey Rims, red anodized, that are also showing some lighter looking "stress marks" radiating out from almost each spoke hole. I replaced them but have them hanging in my shop. Do you think they are safe to ride? I really liked those wheels...

Don't worry, they'll get even worse looking until all the ano is gone. I have a set of Mavics further down the path than yours are.
(The alternating light and dark areas)

Just go ride it, they are fine,

I have some red label Arayas that have a wave in the brake track for every spoke as well. I'll post a pic when I get home.

A lot of lightweight rims from back then seem to "suffer" from this where the sidewalls tend to deflect slightly with the tension from the spokes so that the dark anodizing would wear off at these slightly bulged out areas on the rim. Eventually you will have two tone sidewalls with alternating dark and light areas where the anodizing had worn off. Very common to see on wheelset with very light rims like Mavic's GEL280 and to some extent, their 330GLs too.
I would say, don't worry about it....

Chombi

Happens on some bright rims too, it is just harder to see. Interesting as not all rims are equally effected. Makes me think the ferules were set / dimensioned in such a way that the end of the bell carries the load and or there is compression there, and it is just visible once you lace them up and use them.

I have that on a pair of Red label Araya rims as well, (dark bronze anodizing) Nice light, 32 hole rims...just hanging in the garage...wasn't sure if I should waste the time and effort to find some hubs and relace them. I guess the answer is YES. One has slightly more pronounced wear than the other, so I guess the less worn goes for a front wheel to even out the wear on the pair.

Just check for signs of cracking at the eyelets

I have that on a pair of Red label Araya rims as well, (dark bronze anodizing) Nice light, 32 hole rims...just hanging in the garage...wasn't sure if I should waste the time and effort to find some hubs and relace them. I guess the answer is YES. One has slightly more pronounced wear than the other, so I guess the less worn goes for a front wheel to even out the wear on the pair.

They've been great, durable rims for me. If I weren't planning to go with wider rims eventually, I'd ask to buy yours for when these wear out. ;)

They may go up for trade/swap....not sure if I am up to "Weaving" my own wheels yet....have a nice pair of HF Campys (36) that need hoops at some point too.....that match up just won't work...32 rims, 36 hubs! ;-) I do have some other Araya rims (36) on built up wheels I may rebuild with the Campys if I ever get the nerve up!

If I do get this laced up, where will more of the wear occur, front, with harder braking, or back with more of the running load?
http://i413.photobucket.com/albums/pp216/Holedigger_photos/BS-A-Rims_zpsdb8cf377.jpg

Front,...that is if you brake properly most of the time with more braking biased towards the front wheel.

Here are my (characteristically awful) pics of the front rim:

http://i36.photobucket.com/albums/e26/sstulken80/Bianchi/front_rim2_800.jpghttp://i36.photobucket.com/albums/e26/sstulken80/Bianchi/front_rim800.jpg

The rear rim (not pictured) has more of a smooth, even wear pattern -- likely from just using the rear brake for so long before seeing the light.

In contrast, here's how they looked when I bought the bike 5000 miles or so ago:
http://s36.photobucket.com/albums/e26/sstulken80/Bianchi/IMG186.jpg

(I was kinda obsessed with those new shoes and pedals when I first bought everything.)

WOW! Makes mine look almost MINT! :-)

Here are my (characteristically awful) pics of the front rim:

http://i36.photobucket.com/albums/e26/sstulken80/Bianchi/front_rim800.jpg
.)

Please tell me that you've checked the material thickness of your sidewall... That looks like a classic case of boom-alum when you pump them up and the the sidewall blows off half the rim at Mach 2, usually towards your crotch, and often with shrapnel. Just sayin...seen it happen

I've used a straightedge to check for concavity with the tires deflated, and couldn't find any. I think my pictures just make things look worse than they are. ;)

Not seeing this, I just started a related thread in the Bicycle Mechanics Forum: search for 'scalloped wear pattern on wheelrims". Most respondents said it's no cause for concern.

anodized rims that wear through to the metal below and still look good? no way.

often wonder why manufacturers and the public never see this coming.

i wonder too about flat black cars bikes, motorcycles and other items and what they will look like in a few years. that type of finish always ages like this one. 292739

i've had more pleasant nightmares....