CMA's on my latest project not good news!!!

Wow, you were lucky there. I've just messaged a friend that has a CMA fitted commando telling him about this. As cliffa says, these wheels are potentially 50 yrs old.
If i was looking to buy a bike with these wheels (or any other aftermarket cast wheels from that era) i would taking this problem into account (cost reduction) as in it would need new wheels.
 
I just got them presentable from the sorry state they arrived with me, I'm not a concours type of guy, if you're looking for perfection you're in the wrong place. The polished rim sections were white with corrosion but still had the old tyres fitted until today's visit to the tyre fitters, hence the internal mess.
While it's logical (I suppose) to assume about a fancy car show, the user name has to do with a Japanese copy of a BMW sport tourer.
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CMA's on my latest project  not good news!!!


I was asking and commenting from a metallurgical angle. 🤓

Carry on, you're doing a great job. 🏁
 
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It looks as though only the spokes and inner rim were painted.

Compare the arrowed areas. I reckon it's been cracked for some time at the upper arrow (dark stained crack ), and the stress of the tyre fitting and inflation caused it to rip open around the rim (clean metal crack)


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The dark grey pointed out was the grey tyre lubricant the fitter used, it just got transferred when gathering all the bits up.
 
Wow, you were lucky there. I've just messaged a friend that has a CMA fitted commando telling him about this. As cliffa says, these wheels are potentially 50 yrs old.
If i was looking to buy a bike with these wheels (or any other aftermarket cast wheels from that era) i would taking this problem into account (cost reduction) as in it would need new wheels.
Totally agree, they are not cheap to replace so I've just found out !!
 
Wow, you were lucky there. I've just messaged a friend that has a CMA fitted commando telling him about this. As cliffa says, these wheels are potentially 50 yrs old.
If i was looking to buy a bike with these wheels (or any other aftermarket cast wheels from that era) i would taking this problem into account (cost reduction) as in it would need new wheels.
I did use a dye penetrant crack test on these with negative results but I suspect a more professional approach might have failed them (magna flux or similar)
 
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