mrbubbles

I recently crashed, and my front rim has spot that is compressed inward by 2-3mm, no amount of spoke tightening can get this inward "bump" right, can I hammer it using a mallet back in place? The rim in question is Alex DM18.

ogbigbird

id love to see exactly what it looks like, but i have "fixed" rims in this manner before, usually cheaper ones. if the bump is inward, wouldn't you rather use a pair of channel locks or something like with a rag between the device and the rim to bend it back out. and how long is the spot vs just how deep it is? if you try to fix it, just do little at a time and get it as close as possible without doing harm to the braking surface if so equipt.

Bikehead

I have used a adj. wrench, and very very carefuly, bend the rim
back.Try going a little bit at a time, and again go slow.

jgedwa

Always consider rim "manipulation" as a last resort. If equal spoke tension does give you a straight rim, be prepared to replace that rim sometime. Any rim that is not held true by even spoke tension is a rim that is going to give you trouble.

The perfect solution is to pull the rim off there and see what you have to work with. And that will probably mean replacing it.

But, if money or time are precious, then go ahead and try to move it back in place and see if you can steal more mileage out of it. I have done it. Many of us have. Sometimes it starts to go wonky again on the first ride. Sometime, mysteriously, it lasts forever.

jim

mrbubbles

The centre of the red highlight is compressed inward by about 2 to 3 mm. This rim is available cheap ($20 at LBS), but I like to savage it if I can, I have to relace it anyway should I need to buy a new one.

Homebrew01

Let's say the dent is at spokes #9 & #10. You can loosen 8, 9, 10 and 11. Then tighten 6,7,12,13. This will help force the dent back out. This works for minor dents.

You can also use a rim puller, but they cost more than your rim unless you can borrow one. If you can, you loosen 6-13, pull the dent, then re-tighten.

If you decide to replace the rim and can get one almost the same so you can reuse the spokes, then tape the new rim next to the old rim, lining up the holes. Unscrew each spoke and put it into the new rim, true it up, and off you go.

DannoXYZ 

Loosen the spokes in the dented-in area fully. Lay a 2-ft long 2x4 through the spokes. Hammer the 2x4 using the spokes to guide it. Shouldn't need more than 1-2 hits on an alloy rim. I've had to pound chrome-plated steel rims quite hard many times to get them to conform. But it eventually worked.

daveornee

The plastic deformation in the aluminum rim makes that area weaker.
I would invest my resources in a new rim (DM18) and replace it, making sure you get the tension correct.

operator

If you can't make that area acceptable without screwing up the spoke tension significantly then you need a new rim.

Forget trying to "bend" it back. Waste of time, effort and will not work properly. You have an unexpensive rim that is cheap and easy to replace.