Drivetrain probelms, need some help..


New Member
About a month ago I brought my bike into the shop for a free tune up. I get one whenever I want. I wasn't having any big problems at the time, but on a couple occasions the chain was skipping off of the front chainring, and getting stuck between that and the frame causing me to have to stop and put the chain back on. This I told to the bike mechanic. Came in to pick it up and was told the reason it was happening was because the rear derailer was bent, which they replaced free of charge since I grew up with the owner of the shop.

Went out for my first ride in a while today, since it was rather warm, and the problem has only worsened. Rode about 4 miles, everything was great, and then the chain kept coming off the smallest chainring, causing it to bind up next to the frame. Under closer inspection I noticed it appeared to be bent, the middle and outer ones seemed to wobble a bit too, but not as much. The chain wasn't skipping off the middle chainring. I also thought (and always thought) that the rear derailer that I have doesn't have a strong enough spring in it to pull the chain tight to keep it from bouncing off the chainring. Right now I've got Shimano Alivio drivetrain stuff. Cheap.

SO, since the chainrings are all connected and I can't just replace the one that keeps effing up, guess I'll replace the whole crank right? While I'm doing that, how bouts a new front and rear derailer? I like the XT stuff, but the crank is rather expensive. I'd like to stay around $100 for the front and rear derailers together, and around $150-$200 for the crank. I like the SRAM stuff too, but I've always used Shimano components so I don't know much about the other stuff including Race Face, etc.

So basically I'd just like to upgrade my drivetrain, and make everything solid and dependable. I don't want to break the bank and I don't need the best, most expensive parts. But I want more than the "best bang for the buck" quality if you know what I mean. I plan on going to mt snow this spring and maybe doing a couple races. I ride a Felt Q520, nothing too spectacular, the other reason why I don't think its necessary to spend $500 on these upgrades.

Any help would be greatly appreciated..


Formerly M3Tim
Something doesn't sound right. I think the rings would have to be pretty bent to causing a problem like this. Sounds like the front der. is not adjusted/mounted correctly. Can you post up some pics of the setup. Even Alivio stuff should work better than that.

If you are set on buying new stuff, I would go with the new SLX stuff. Looks almost as nice as XT and and quite a bit cheaper.

Spending that much on a $500 bike doesn't seem worth it.



Like a Jerk
i bent the hell out of the rings on my first bike. like yours, they where riveted together and un-removable. you can try to mend them with a hammer and file...

the rear der wasn't bent, the hanger that attaches it to the frame was. this is a common thing that happens from aggressive riding no matter what kind of rear der you have. only thing that plays a part is what kind of hanger your frame was built to run.

no sense in upgrading that bike too much, so i'd recommend dropping by your shop to get a new crankset (with removable chain rings) and a tune up.

if you're set on the upgrade, i'd second the slx recommendation.


You may want to check your chain; a stiff link might cause this type of thing as well...


New Member
Another thing I was thinking is that I rarely ever use my middle chainring. Could using the small chainring all the time cause excess wear in it, causing this problem to arise?


The Hat
Team MTBNJ Halter's
Another thing I was thinking is that I rarely ever use my middle chainring. Could using the small chainring all the time cause excess wear in it, causing this problem to arise?

only if you're cross chaining .. small ring, small sprocket or big ring, big sprocket is not a good combo and will cause wear .. there are other combos in the middle you can ride on to replace those extremes


Active Member
I bet you only have an adjustment problem. Even the lower end shimano stuff works very well. Usually the limitations are in the durability department as you ride farther and harder.

Have someone else take a look at it. Don't spend "a couple hundred bucks" on this.

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