Cracked rim?
12-21-11, 04:15 PM
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Cracked rim?
I have a set of sun mistral rims and i was looking over them today and noticed in both rims in the same place (under where the sun mistral sticker is) there seems to be a vertical line where the rim is glued together, it seems. The rear rim line seems to be more visible than the front rim, but both have the line through the rim. I've never noticed this before on other bike rims... Is this common on older bike rims? Is it safe to ride on? Or is this a crack that I should be worried about?
this is the back rim.
this is the back rim.
Last edited by octophasic; 12-21-11 at 04:23 PM.
12-21-11, 04:25 PM
#2
Keener splendor
You mean the seam???
All the rims that I own have seams. The seam is often a weak point and can crack. It's not glued but brazed or welded.
I don't know if yours are safe to ride on given the fuzziness of the photo.
All the rims that I own have seams. The seam is often a weak point and can crack. It's not glued but brazed or welded.
I don't know if yours are safe to ride on given the fuzziness of the photo.
12-21-11, 04:31 PM
#3
Banned
All aluminum rims are an extrusion, rolled into a circle,
there are pins bridging that seam,
plus the tension of all those spokes is pulling the rim smaller
so the seam is further in compression..
spend more money and the rim makers weld the seam
then machine the weld bead back down.
processes that cost more to do.
there are pins bridging that seam,
plus the tension of all those spokes is pulling the rim smaller
so the seam is further in compression..
spend more money and the rim makers weld the seam
then machine the weld bead back down.
processes that cost more to do.
12-21-11, 04:36 PM
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sorry for the fuzziness of the picture, but thanks for the info. Just when I saw it, I immediately went and looked at my other bikes wheels and didnt see these seams. So I got worried.
Would you guys imagine the cost of making a bicycle rim seamless and using CNC 40 years ago? 
12-21-11, 11:21 PM
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More modern rims usually have welded joints. You'll often see some excess weld on the inside, but the outside brake tracks will be machined hiding the joint.
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FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
12-21-11, 11:43 PM
#7
Constant tinkerer
