With this Quick Question series we volition present fast fixes and collect comments from seasoned riders around specific D.I.Y. mountain bike repairs. While much of this trailside triage is covered in our repair articles and videos, this is a space for longtime riders and readers in the Singletracks customs to share their knowledge. Please blazon your related experiences and communication in the comments below. Do yous take a quick question? 🤔 E-mail [email protected]

A mountain bike without scratches and dings is likely i that hasn't been ridden withal. Playing in the rocks tends to add a lot of grapheme to our gear, and rims are no exception. Whether we fail to check the tire pressure level or are simply riding fast on rough trails, well-nigh everyone eventually bends an aluminum rim. It can even happen with college pressures and inserts if you're really pushing the step, and often the dent makes it difficult to then achieve a solid tubeless seal.

Co-ordinate to Dustin Adams at We Are I Composites, bent rims are ane area where carbon fiber rims often triumph over blend. Carbon can be laid upwardly to provide meaning movement during a rim touch, allowing information technology to compress into an egg shape and leap back, where aluminum volition flex to a point, and subsequently that betoken, it will not render to the original desired shape. A counterargument is that aluminum rims can oft exist repaired if bent, where a broken carbon rim needs to be replaced in about cases. We're not hither to help yous decide between blend and carbon hoops, but to ready the dented metal.

There's a adept gamble that blend circumvolve can be bent back into a shape that your tire and sealant will accept. In the best case scenario, only the bead-claw bends, and it tin easily be pulled back to a tall enough wall to concur the tire and proceed on rollin'.

Both the Syncros Revelstoke 1.five and Crankbrothers Synthesis I9 aluminum wheels I tested last year ended up with dents in the rims later I reviewed them that had to be hammered out. The indentations were sharp plenty that they pressed the tire bead out of its aqueduct, preventing a proper tubeless seal. The solution in both cases was constitute in a few chunks of medium-hardness wood, a pallet, and a hammer. Consider turning off your perfectionist switch for this 1; it's time for a classic good-enough repair.

Notice a soft surface to lay the bike on where the hub tin rest without applying much load on the spokes. A pocket-sized pallet like this 1 that came attached to a washing machine works well to hold the wheel still without scratching the rim finish. And so, any piece of forest that'southward about the size of the dent volition practice well to reverse the impact from the stone strike without creating whatsoever sharp edges inside the rim. Middle the stick and smack abroad until the bead claw becomes fairly straight over again. It doesn't take to be perfect to hold the dewdrop seal, and often bending it back 50% volition be sufficient. Then, truthful the wheel, mount the tire, and savour!

If yous happen to accept a bench vice with a soft clapping jaw, that tin also practise well to bring the rim back to a straight-enough opinion. Try not to clamp too much of the rim, as you tin can end upward bending a larger portion and so chasing the dent effectually the cycle and somewhen needing to replace the rim.

If yous merely need to straighten things out so you can ride or race, and don't care what the finished product looks like, take hold of the bead hook with a set up of plumbing pliers like those pictured beneath and gently tilt it back in the right management. I like to wrap the jaws in onetime jeans so they don't cutting into the blend and create issues for the tire. Have intendance not to bend too far, as it'due south easy to dent the outer or inner rim profile with the pliers and create new problems. The rim record may need to be replaced if there are cuts from the bear upon or pliers.

If yous've huffed and puffed enough and tin't get the bead hook and tire bead to play together there is another fob to try. Before tubeless rims existed, we would take a tube that's smaller than the bore of the wheel, like a 26″ tube, and cut it along the outermost edge all the way around the circle. Then, insert the valve and stretch the splayed tube carcass over the rim like a giant safe band earlier installing the tire over the top of the tube. The tube safety between the tire and rim will take up some space from the dents, typically assuasive the tire to seal and be safely ridden.

The pallet can likewise work to re-round wheels that have been dented inward, in the egg-shape direction. I worked at a shop in Florence, Italian republic, where we serviced loads of DH race rigs, and I learned this move to save customers a little money and get them back on rail. Identify the office of the rim that'southward bent inward (toward the hub) between two boards. Then place a hitting lath within the rim and bang on it until things are round enough to ride. You'll typically need to tighten the spoke nipples where the bend is unless y'all are magically able to get the cycle back "in round." This is definitely not an platonic fix, but it might save your MTB vacation or race twenty-four hour period.

What helpful tips do y'all accept for straightening rims that won't hold a tubeless seal? Delight share them with us in the comments below.