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Trek 1.1 chainring issue
#1
Hi all! Recently became the owner of a new Trek 1.1 road bike. Taking it out on it's maiden voyage, I noticed the chain rubbing up against the front derailleur. It happened while the chain was on the big chainring up front (It's a compact setup) and the larger cogs in the rear.

Also at this time noticed that the chainring wasn't perfectly flat, in fact it had a small amount of wobble. The noise was sporatic, the chain rubbing as the chainwheel went through it's out of round bit.

Took it back to the lbs the next day, guy worked on it for 20 minutes- looked like he tried to tweak the chainwheel using force, couldn't quite tell what exactly he was doing. Then he asked me to test ride it.

Same deal, chain rubbing front derailleur. Guy told me not to run it in those gears as it was cross chaining.

Rode her into work the next day keeping it out of the cross chain gears and it was fine (did note that morning that the chainring still had that bit of wobble) until I put it into it's highest two gears for some sprinting fun. (Front big ring, rear two smallest rings) Then it rubbed again, this time on the other side of the derailleur cage. It was more pronounced when I was really pedaling it hard. I have read that you can "trim" the front derailleur to rectify the rubbing, but didn't try that yet. Still trying to get used to the unusual (for me) method of shifting.

So my question boils down to- does it seem normal for a new (presumably quality) bike to have some chainring runout? Will this affect the drivetrains longevity? Am I worried about nothing? Thanks for your consideration.
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#2
If this is a new bicycle have them replace the front crankset, it should be straight for a long time, and yes you have to use the trim, that is how the shifters work. and yes, do not cross the chain more than 5 or 6 cogs for best performance. If they do not replace the crankset contact Trek and explain your situation to them and have them deal with the shop. Do this right now, do not let to much time go by and get any work documented.
There are two kinds of people in the world, "Those who help themselves to people, and those who help people!"
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#3
Thanks. I'll be the LBS' first customer this morning.
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#4
Brought it in this morning. Different mechanic. He had it pulled apart and diagnosed in five minutes. Bad spider. A week to get the part in. This is why it's good to have more than one bike!
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#5
Got the Trek back from the LBS today. They installed a really nice crankset- an obvious upgrade from the original. I can't say enough good about them, or Trek's warranty service.

Went for a spin around the neighborhood, and man she rides so sweet! Buying a new bike was on the bucket list- and now I can check that one off .

Thanks a lot PK. Was seriously mulling riding her as she was, your post to get her back to the LBS pronto was just the kick in the rear I needed, and the end result is great.

Now about my OTHER bike. You see, once every pedal revolution there is this annoying click...
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#6
I am glad it worked out. I know it sucks to put your foot down sometimes and all cases are different. Most shops I think try the best they can to retain a happy customer. I know I would go out of my way to keep and make a happy customer, one to enjoy riding bicycles as long as they can as burden free as possible. Though I no longer sell new bicycles I still sell high quality used bikes and hope to have a long time relationship with the people that buy my bikes. So until you can and even after you are able to do your own wrenching, if you have a good local LBS stay friends with and support them when you can. With sites like this and a good local LBS you can do anything ! welcome aboard.
Now with your click, think about this. Then let your mind go to work.
clicks need to be timed, you did that when you said every pedal revolution.
perfect. now think about what the parts of the bike are doing that equal one pedal revolution to help pinpoint the area of concern. I will not tell you as yet because I want you to figure it out on your own for the moment. Do not worry because others will chime in. remember click timed with one pedal revolution, step one is done, now isolate that area. but in the meantime how old and or how many miles do you think the bike has? what do you think on the bike turns once with a pedal revolution? is it the wheel ? is it the chain? is it the hub? or is it he pedal itself? or maybe the spindle? things like that.
There are two kinds of people in the world, "Those who help themselves to people, and those who help people!"
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#7
(08-10-2013, 12:49 AM)painkiller Wrote:  I am glad it worked out. I know it sucks to put your foot down sometimes and all cases are different. Most shops I think try the best they can to retain a happy customer. I know I would go out of my way to keep and make a happy customer, one to enjoy riding bicycles as long as they can as burden free as possible. Though I no longer sell new bicycles I still sell high quality used bikes and hope to have a long time relationship with the people that buy my bikes. So until you can and even after you are able to do your own wrenching, if you have a good local LBS stay friends with and support them when you can. With sites like this and a good local LBS you can do anything ! welcome aboard.
Now with your click, think about this. Then let your mind go to work.
clicks need to be timed, you did that when you said every pedal revolution.
perfect. now think about what the parts of the bike are doing that equal one pedal revolution to help pinpoint the area of concern. I will not tell you as yet because I want you to figure it out on your own for the moment. Do not worry because others will chime in. remember click timed with one pedal revolution, step one is done, now isolate that area. but in the meantime how old and or how many miles do you think the bike has? what do you think on the bike turns once with a pedal revolution? is it the wheel ? is it the chain? is it the hub? or is it he pedal itself? or maybe the spindle? things like that.

This will likely be the last time I ride a brand new machine. It's so fine. Muscle power translates into speed, almost without thinking.

Today wiped down the chain(other, commuting bike) until it was clean. Then doused it with Epic Ride chain lube, as per instruction. Rubbed out the excess.


Hm. Don't have the special tools at hand to take the BB apart. That's where I think the problem lies. It's a bearing I'm thinking.
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#8
PK, an update. After the chain cleaning and lubrication, the clicking did work itself out. This bike is a rough old lady, but she's my favorite commuter. Can thrash her around through the roughest of roads and she sails through everything. The aforementioned Trek is a real beauty, and a joy to ride, but every little pothole makes me hesitate cuz I don't want to mess her up, LOL.

Thanks for your earlier invaluable advice on the new bike.
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#9
good deal Robert, glad it all worked out. when you get some time post some pics of what you have in the "Show off your bike" Header.
I always recommend for those starting to work on their own bikes to just buy the tools it takes to do the basic stuff specific to their bike. Allens, cone wrenches, cup/bottom bracket tool, chainwhip, cresent wrenches, 8,9,10mm open end wrenches. things like that and you may already have. Just look @ your bikes and see what you need to keep them up to snuff. I say tools will pay for themselves over and over once you get the hang of it and start wrenching on other peoples bikes. Freewheel and cassette removal tools are fairly cheap. Most overlooked by home mechanics is the Derailluer Alignment Gauge or called the "Dag". It is the most critical tool in the arsenal. over 90% of shifting issues are related to the rear hanger out of tolerance. It does not matter if the bike is new fresh out of the box it must be checked first, so used bikes do not stand a chance. they need to be checked. Take one step at time and enjoy the ride brother!
There are two kinds of people in the world, "Those who help themselves to people, and those who help people!"
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