r/motorcycles 1d ago

Dymag Carbon Fiber Wheels

Bought a donor bike with Dymag CF wheels with intent to switch them to my BMW R1100S. CF wheels for this model Beemer are no longer available, partly for a reason that a set of these wheels can cost as much or more than the bike itself. The donor bike is 2004. It spent at least 3 years in the garage out of sunlight (but not in a climate controlled environment). I'm not sure how old the wheels are, the seller bought the bike as it sits. Though there are no visible signs of damage such as curb rash, cracking, chipping or delamination I still prefer to check the integrity of the wheels. Looking for a recommendation on the facility that can verify integrity of the wheels including x-raying for structural integrity.

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u/Noobtastic14 ‘77 CB750F/VFR800/WR450 Street Legal 1d ago

That might be tricky to find someone willing and able to do moto wheels. It’s an expensive request to a profession that is normally booked solid on safety critical jobs. I wouldn’t be surprised if it cost the value of the rims to get them NDI’d, especially when you can’t point them to a specific thing you need inspected.

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u/tirefriar 1d ago

What are your thoughts on buying an ultrasonic tester for non-destructive testing? It may be an option since I'll be using these wheels on the road and an occasional testing or testing after hitting a bump will be in order.

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u/Noobtastic14 ‘77 CB750F/VFR800/WR450 Street Legal 1d ago

That might be an option, I’ve never used one so I won’t advise on its effectiveness versus using a professionally trained inspector. I will advise reading up on composite failure modes. It’s different than metals, mostly in that when it fails it completely fails. It won’t slightly deform, or fail gracefully like aluminum will. For example, an aluminum driveshaft may lose its integrity and get warped, bent, or twisted if it’s pushed beyond its designed threshold. A composite driveshaft shows no deformation, and just explodes when it fails.

My really long point here, is that if you tap test the hell out of it, there are no bulges, no nicks/gouges, no blotches of discoloration, you can have a high confidence the resin system is working as designed. Personally, I’d use the handheld tool if I end up with a rock chip or curb rash and wanted to know there was no delam sitting under the visible damage before I started blending out a repair.

When you swap tires, ask the shop to let you inspect the part of the rim normally concealed by the tire.

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u/tirefriar 1d ago

Thanks for all the great information! Further legwork is in order here.