Bent Chainring
 

Had to "thread the needle" last week and was unfortunate enough to be on the downstroke when I swerved and caught my pedal on the sidewalk curb HARD. I kept it together and avoided a potentially life-endangering scenario, but I noticed that I did bend my main sprocket a little bit. Now the wobble is enough to just fit within the boundaries of my front derailleur. The chain sometimes rubs against the edges of the cage depending on what gear I'm in. It doesn't look like I bent the frame, but I'm wondering if it's okay to run it like that, and if so for how long. Should I replace the crank or can I just get away with replacing the outer ring? I commute on the bike 14 miles round trip every day. My bike is a 2010 Surly Long Haul Trucker with what I believe is an Andel RSC6, 26/36/48t. Thanks.

Joe

Wow! I'm impressed and didn't know that was possible.

If you can replace your chainrings (you can on most but not all cranks) AND the crank itself isn't bent (and there isn't play in the bottom bracket), then I'd try changing just the chainring. If something else is blown, then you've got to replace more.

You may need to replace the chainring but you can also try to straighten it. Find where the wobble is and then use an adjustable wrench to straighten out the bend. Get as much bite as you can on the ring with the wrench and bend it is small amounts until it's as straight as you want it to be. At worst, you can't fix it and will have to replace the ring. At best, you'll have a great mechanical story to tell.

Andel is the Generic Crank QBP gets for their LHT build , so now you might look at an upgrade .

chainring bent?, take it off lay it on a flat tabletop..and see .. how much ..

You might have bent the crank spider..

whole crank bent. the pedal wont feel right as it goes around. too..

If it's only the chainring, I used a wrench to straighten one of mine. Slowly turn the crank and use the wrench to pull the chainring straight. Don't try to do it all in one pass. I think I did four or five passes to pull out a 1/8 to 1/4 inch bend on a mountain bike chainring that took a good hit. If you can take off the chainring it's easier to do with a hammer and a flat concrete surface. Look for cracks and replace it if needed.

If this was due to a pedal strike, I would double-check the crank-to-bottom bracket attachment (this is square taper, right?) before bending anything.

Thanks for all the replies to this thread. I brought it to the neighborhood repair shop, and apparently Surly sells a steel replacement outer ring that I'm having them put on this week. I'm going to have them check out the crank-to-bottom bracket area for any further damage as well.

surly's chainrings are cheap forged steel and since the teeth are not ramped they are technically incompatible with shimano triples (poor shifting). FSA makes great ramped CNCed chainrings.