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Recently bought a pair of used zipp 808 clinchers and was a bit disappointed when after a closer look discovered a couple of small concavities (something like 1mm in diameter) on outer side of the rims here and there. Apparently someone attached too much power to levers (I just can't believe one can use a screwdriver for this purpose on a zipp wheelset) when he or she was trying to remove a tire. I'm wondering how critical this damage is? In terms of durability, riding quality, aero, etc?

enter image description here

  • Is it carbon or aluminum ? – Batman Jun 15 '15 at 20:56
  • aluminium of course. – krakovjak Jun 15 '15 at 21:02
  • Could have also been a rock stuck in a brake pad, or a drop during off bike maintenance. – Deleted User Jun 15 '15 at 21:44
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    To answer all your questions: zero. No effect. Nothing to see here. Ride on. – andy256 Jun 15 '15 at 23:30
  • I should also say that I thought your response to @Batman was quite rude. People ask you questions so that they have enough info to help you. The basic rule is be nice. – andy256 Jun 15 '15 at 23:37
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Is there a matching ding on the other side of the rim at about the same place? If yes I'd say it the bike was ridden hard into a pothole with a sharpish edge.

Source - I found an unexpected kerb while riding recently. The front wheel came up in time but the back wheel didn't rise soon enough, and I pinch flatted with cuts ~10mm long, wrecked the tyre, and now have two small dents just like this, but a little longer and shallower.

Personally I'd remove the tyre and gently file off the lip shown in the photo. Look inside for a matching rim. File off no more than you have to. The braking surface should be smooth and not able to catch the brake pad at all. Don't file the outside (round) edge of the wheel, and don't bother trying to fill the gap.

If you're concerned about weight imbalance, file all the dinks out and then put the rim, tyre and tube back in the frame while its off the ground. See if it has a definite "heavier" point that settles lower all the time. Use some clip-on spoke reflectors as weights to balance your wheel again.

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    Spoke reflectors on Zipp 808? I really, really want to see the internet's reaction to that. – ojs Nov 28 '15 at 10:54
  • @ojs: Obviously the correct solution is to find the heavy side of the wheel and drill holes there! – John Zwinck Nov 28 '15 at 13:44
  • @ojs internet might be okay with them if they are areo and super expensiveness made out of carbon. Just get them into the right blogger's hand and have them twist themselves into knots justifying the cost. Before you know it, it is all systems go! – Rider_X Nov 28 '15 at 17:11
  • @ojs I mean these things dx.com/p/… they're really good reflectors, they don't stand out like the horrible yellow ones, and they're relatively small. I put some on all my bikes. – Criggie Nov 28 '15 at 20:59
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If there are no barbs that are catching the tire / tube and causing flats, or catching on your brake pads, it's probably fine, you probably won't notice any difference in ride quality.

If either of those is a problem, get a fine file and work it smooth, trying not to damage the existing machined brake surface.

Balancing a bicycle wheel is mostly unneccesary. Jobst Brant (author of the book the bicycle wheel, doesn't see the need either). You can see a discussion about this on usenet archives here: http://yarchive.net/bike/wheel_balancing.html

More importanty, you want to consider whether the rim is bent, cracked, or out of true.

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