Tech Tuesday - Fixing Rim Dents
A sizeable dent like the one shown above may look fatal, but there is a good chance that the damaged rim still has a lot of life left in it. While disc brakes may have lessened the consequences of denting a rim sidewall, it is still good practice to pull out the damaged section. Why? Many dents are bad enough to actually compromise a tubeless setup's ability to hold air, allowing pressure and sealant to leak out at the site of the damage. In extreme cases, the tire's bead may not even be held in place safely.
While some repair jobs require very specific tools to perform, fixing a dented rim only demands the basics: a large adjustable wrench and metal tire lever.
Want to use the correct tools for the job? Morningstar Tools manufactures this clever item, their ''Rim 'Rench'', that is specifically designed to pull out inward dents on rims. It is shaped to not harm the rim wall, and is thin enough to pull out the smallest of imperfections. It can be found on the Morningstar website for $16 USD.
What's needed: • Adjustable wrench • Metal tire lever • Felt marker | Some helpful pointers: • Using a metal tire lever (or any other thin metal object) between the outer rim wall and the wrench will prevent the edges of the wrench from damaging the rim. It will also help to keep you from bending the rim wall out too far. • Much like straightening a brake rotor, this repair job is all about going in small increments. You'll just make more work for yourself if you try to bend too much too soon. • It's mentioned again below, but we can't stress this enough: inspect the rim for cracks after fixing the dent. Although it is unlikely to occur, a rim sidewall blowout, especially up front, will likely spell disaster on the trail. |
Step 1 - Star by taking the damaged wheel off of your bike and removing the tire. It is also a good idea to slip off the rim strip if you are not using a stick-on, tubeless rim tape. If you are, be careful during the repair so as not to damage the tape.
Step 2 - Locate the damaged section of rim wall and use a felt pen (or a white-out pen if the rim is black) to mark the points where the damage begins and ends. This makes it easy to see where you have to work your magic, as well as allow you to easily find the dent as you progress.
Step 3 - Take your metal tire lever and place it up against the outer rim wall, directly over top of the dent. Next, starting at one end of the dent, close down your adjustable wrench over top of both the damaged rim wall and the tire lever. Hold your thumb down firmly onto the wrench's adjustment wheel.
Step 4 - With one hand holding the metal tire lever in place, use the other to pull the rim wall out. Start with small motions, working your way along the offending area.
Step 5 - Inspect your work before reinstalling the tire, tube, and rim strip. Look for hairline cracks that run lengthwise along the inner rim wall - a single crack requires the rim to be replaced as a rim failure on the trail can have dire consequences. If you left the wheel's tubeless rim strip on during the repair, be sure to check it for any tears that may have been caused by the wrench. The photo above shows a before (left) and after (right) view of the damage and the repair.
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The best way to remove a dent is to put a flat, steel surface on each side of the dent (the small, flat Park 8, 10, or 12m wrenches work good). Squeeze them together with Vice Grips and the dent is flattened, instead of re-bent the other direction.
If it's a really bad dent or a real strong rim you may not be able to completely flatten it, but dont use that tool!
Economical to buy another rim - NO.
Can't fix it? - RIDE IT UNTIL IT DIES
Zip ties are not the answer.
Agreed. I have a limited budget and currently limited skills to prevent this kind of damage for occurring. Hundreds of dollars spent on dented rims is not an option
RIDE UNTIL IT DIES
If the tyre stays on, leave the ding.
Better that than to crack the rim!
If you mess one of these rims up.. then spend the £30 on a new one and stop being such a damn hoonigan!!
Anyway, I found this article before trying this and since I didn't have a flat metal lever tool I improvised. I taped up a snowboard edge sharping tool with packaging tape for the the outer edge of the rim. It worked good for me. I took it pretty easy and put some packaging tape over my tubeless rim tape to protect it as well as the inside of the rim I was edging out with the crescent wrench. I did very small sections at a time. My dent was probably as bad or worse than the one in this article. I notice a very slight line on the outside of the rim now. It also appeared to have very small hairline stress cracks on the inside from bending it back. However, It is holding Air for now and it's MUCH straighter than it was before! I was worried but it was worth it I think. I'll know after a few rides. When I cranked the wheel with the bike upside down before the repair the rear was wobbling all over the place! Now hardly at all. So, it I hope did good? LOL Thx for the help..
P.S. I also like the Vice Grips idea by Protour.
p.s theres another dint on the other side of the rim. ; )