Mend a Bent Wheel
The issue: That downhill section looked awesome. Til you careened front-wheel-first into a formerly invisible granite boulder.
The solution: So you’ve taco’d your wheel. Hopefully you were getting rad, and hopefully someone got a good picture of it. Oh, and hopefully you’re ok.
The first thing to do with a taco’d wheel is to come to grips with the fact that your rim is probably trashed. (Exhale.) The goal now is get it to the point where you can ride home to replace it. If the bend isn’t too bad, you might be able to squeeze a bit more life out of the wheel, but understand that it’s no longer as strong as it used to be.
On to the fix. We’re starting this fix with the assumption that, prior to your graceful bout of radness, your wheel was (1) straight, and (2) the spokes were at the right tension. With that in mind, we’re going to try to reverse the taco-ing process.
Step one: Take the wheel out of the bike.
Step two: Hold the hub and give it a spin. Is it a complete mess, or is there an obvious bend in one spot?
If there’s an obvious bend in one spot, grab the wheel on either side of the bend so that the bend points away from your body and is facing down. Now smack the wheel on the ground. If you’re thinking, “This is an expensive wheel and this feels really destructive,” then you need to re-read the part above about how your wheel is already trashed and you just need to get home.
Start the ground-smacking somewhat gently, checking the straightness after each smack. Gradually increase the severity of your smacks until the wheel is passably straight.
If your wheel is a complete mess without one obvious bend, the process is essentially the same, but you’ll need to be a bit more careful about which bend to start on. Start with the worst bend, but don’t worry about getting it straight before switching to another one. The wheel is a dynamic unit, so straightening one bend may affect others.
According to Noah, “You should be able to get the wheel straight enough to ride by smacking it around. As long as the rim isn’t cracked, I have never failed to make a taco’d wheel at least ridable. If you’re still rocking rim brakes, you may need to fine tune the wheel by truing it, or there’s a possibility that you’ll just need to leave the brakes open to allow the rim to roll through the frame.”
“Some will say that, before doing any smacking of the wheel, you should loosen the spokes in the area of the bend. Personally, I don’t subscribe to this method. The spokes were (theoretically) at the right tension before the wheel taco’d, so monkeying around with the spoke tension prior to bending it back doesn’t help the rim go back to its original state.”