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I just bought my new bike about a month ago and the chain is rubbing the inside of the front derailer when I'm in my 39/23. I remember the bike shop saying that if I couldn't find the time to stop by I could fix it myself by adjusting the inside screw an eighth of a turn. I can't remember if I should go righty tighty or lefty loosy though.

Obviously I'm not a wrench head.

Can someone help?
 

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I'm not sure which way you should go with it. I would play around with it anyway to get used to the limit stop screws. You will see the derailleur move when you turn the screws, so if it is the wrong way, just turn the screw the other way.
 

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NeoRetroGrouch
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gnauss said:
I just bought my new bike about a month ago and the chain is rubbing the inside of the front derailer when I'm in my 39/23. I remember the bike shop saying that if I couldn't find the time to stop by I could fix it myself by adjusting the inside screw an eighth of a turn. I can't remember if I should go righty tighty or lefty loosy though.

Obviously I'm not a wrench head.

Can someone help?
You should not have to adjust the limit screws unless you changed something. It is most likely that the cable has stretched a little and that you need to tighten it with the barrel adjuster on the head/down tube. Turn it out (counter-clockewise from the front) 1/4 turn and see if that helps. Some models may have the adjuster in-line.

Do not just play with the limit screws. If you actually have to adjust them, start from the beginning (see the Park web site) and do each step in turn.

If it is one of the models with no adjuster barrel and you have no way to adjust your cable tension, B!tch - a lot.

TF
 

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It's simple

gnauss said:
the chain is rubbing the inside of the front derailer when I'm in my 39/23.
I'm assuming that the 23 is your largest cog. If you are sure that you have shifted "all the way down" with the front derailleur, then it is most likely the limit screw. The confusing thing is that these things don't turn by themselves, so it's not clear why you have this problem now when you didn't have it when the bike was new. That said, if you turn the screw "out" (counter clockwise) that will allow the derailleur to move closer to the frame and eliminate the rubbing. Make sure that you have repeatedly shifted the derailleur so that it is in the fully relaxed position.

As a side note, derailleurs (front and rear) are not really that complicated. I would suggest that you spend a few minutes watching the derailleurs operate as you shift through the gears. You will gain some valuable knowledge about how the bike works, and will be able to confidently make these adjustments yourself.
 

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I'm having derailer problems too, and I've had the LBS try and fix them once. This is my first road bike and I only have about 50 miles on it.

Occasionally when I'm shifting down to the lowest front cog, the chain will fall off- probably once or twice a ride. My whole setup is Shimano 105s.

It is also difficult to shift to my highest front cog. Now this seems like a no brainer to me- the front derailer is obviously too far to the left and causing me issues. The problem is that I have no idea what to adjust- I see two screws on the front derailer- one closer to the frame and one farther away- should I try turning these? One? Both? Which direction? When I took it to the LBS they run it through all the gears and it works fine for them on the stand.

I'm not sure if one of these screws messes with the tension- I've watched the derailer cable move when I shift and I noticed that shifting one way pulls the derailer while shifting the other way loosens the cable and lets the derailer move on it's own. So I don't want to screw anything up :(
 

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captal said:
I'm having derailer problems too, and I've had the LBS try and fix them once. This is my first road bike and I only have about 50 miles on it.

Occasionally when I'm shifting down to the lowest front cog, the chain will fall off- probably once or twice a ride. My whole setup is Shimano 105s.

It is also difficult to shift to my highest front cog. Now this seems like a no brainer to me- the front derailer is obviously too far to the left and causing me issues. The problem is that I have no idea what to adjust- I see two screws on the front derailer- one closer to the frame and one farther away- should I try turning these? One? Both? Which direction? When I took it to the LBS they run it through all the gears and it works fine for them on the stand.

I'm not sure if one of these screws messes with the tension- I've watched the derailer cable move when I shift and I noticed that shifting one way pulls the derailer while shifting the other way loosens the cable and lets the derailer move on it's own. So I don't want to screw anything up :(

to adjust the front derailluer. Shift into the small chainring, disconnect the cable from the derailluer. the normal derailluer position without any tension is on the lowest chainring one of the screws will adjust this, some have an L or H by them, adjust the appropiate one so that the cage is centered on the chainring. Be sure that it paralle to the ring. Set the frame adjuster down to where there are 2 threads showing or if you have an adjuster with 4 settings, set it in the lowest one. This will give you room to adjust if there is too much slack in the cable. Be sure that the shifter is set to the small ring and has no clicks left in it. Pull the cable taut with your hand and put it back in the derailluer. this should be done after you have made sure the derailluer is parralle to the rings and has a pennys thickness above the large ring. or see http://www.parktool.com/repair/readhowto.asp?id=75 for a more detailed description. I too had a chain that would fall off when shifting to the lowest gear. An LBS that had built the bike put on the triple crank botton bracket that put the chainrings to far out. i must have adjusted this thing about 6 times before i figure it out. That is all about chainline dimensions also on the park web site.

to adjust rear derailluer see http://www.parktool.com/repair/readhowto.asp?id=64 keep in mind that the shifters need to be in the position where the derailluer would fall if left untensioned. on the rear that would be on the smallest cog. Adjust the derailluer to run smoothly on this cog. it too has a high and low position. the frame adjuster and adjuster on derailluer should have at least 2 threads showing to give you room to adjust slack out of the line. hope this helps.
 

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I'm getting quite frustrated. I left work early thinking I'd be able to get these adjustments in and get a ride in- I've just spent the last 45 minutes on the front derailer and I can't find a point at which the front chain doesn't fall off the front sprocket but shifts up onto the biggest cog.

I slightly tweaked the rotation- about 1-2mm countclockwise because it looked a little off. I've been messing with the limit screws and cable tension and cannot find a happy point. I even adjusted the cable tension and limit screw so that the chain is rubbing when on the innermost cogs and it's still falling off when shifting. I think the problem is that I try to shift from the large cog, the shift doesn't occur, and I hit the shifter again, the chain tries to jump down to the smaller cog but misses and falls off.

Perhaps my high limit screw is too far out- I'll give it another whirl. The tension is such a tough factor to figure out because it can move the derailer a lot one way or the other.
 

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Alright... after another 15 minutes of screwing around I think I found the problem...

When I'm in the lowest cog on front, and I shift up- I have to shift up hard and it makes two clicks and moves to the middle ring (if it only makes one click it doesn't go all the way up). When I'm on the middle cog I can only shift up one more click and it usually goes up to the top cog (I'm still having problems getting the adjustment perfect- but it goes up most of the time).

When I'm on the top cog I have to shift down two clicks to get to the middle ring- the problem is that when it's on the top cog I can only shift one click down- I then have to release and shift another click, but at that point I can accidently shift two clicks- bringing the chain down to the lowest cog, or potentially missing the lowest cog and the chain comes off.

Is this normal? I noticed that the shifters for the rear derailer I can only shift up (to a smaller cog) one click, but I can shift down to a larger cog up to three at a time (three clicks). I'm fine with that- the rear works great- it's the front that's a problem.

Help! Is something defective or is that by design???
 

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no this is not normal. it should never fall off. Maybe if you down shift while under lots of power, but never/rarely is the norm. from the park tool site



Shift chain to innermost rear sprocket and innermost front chainring. Inspect derailleur for marking indicating "L" screw.
Check inner wire tension. It should be fairly loose at this time. If inner wire is taut, turn barrel adjuster clockwise into housing. The barrel adjuster is typically located where the cable housing enters the shift lever. If barrel adjuster is already fully turned into housing, loosen inner wire pinch bolt, slacken inner wire and retighten bolt.
Sight gap between inner chain plate and inner cage plate. Only a small gap should be visible, about 1/16" or 1mm, about the thickness of a dime. Test the shift by shifting chain to next chainring then shift back to the innermost ring. Do not use the shift lever. Pull on the inner wire to shift the derailleur. Using the lever may confuse limit screw issues with cable tension issues. If chain shifts quickly, limit screw setting is adequate.

this is tricky but you should be able to adjust the limit screws so the chain lands on the sproket without falling. this can be done without the cable connected. If you recently put on a different bottom bracket than the one that came with this unit or swap parts to/from another bike with similar groupo this could be a chainline problem. took the triple crank and put it on frame/bb that had a double for example.
 

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Nope- this is a stock Lemond Big Sky SL with a full 105 set straight from the LBS.

Do you think the tension is messing with shifting? I can't seem to find a tension that works...
 

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captal said:
Nope- this is a stock Lemond Big Sky SL with a full 105 set straight from the LBS.

Do you think the tension is messing with shifting? I can't seem to find a tension that works...
Assuming that it's 105-9 (I have not worked on a 105-10):

Set the cage parallel, the tooth/cage gap and set the inner gap and outer gaps as posted above.

Set the tension so that you have, when going from granny to large, two positions on the small ring, two positions on the center ring and one position on the big ring. Going down, you should have one on the big and middle and two on the granny.

Put the rear in a middle cog. Put the front all the way to the inside. One small click to trim the granny. One click should go to the middle. One click should trim the middle. One click should go to the large. When it works well here, move the rear to two cogs from the largest. Should still work and should have chain rub on the two outside trim positions for the granny and middle. Try 2 cogs from the smallest. Work here? Continue with the largest and smallest cogs if you want, but it's ridable here since you would seldom shift to a smaller ring when in a small cog (and the other way around) anyway.

TF
 

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It is a 105-9

Does granny = small = smallest front ring? You used the terms interchangably so I'm not sure. What do you mean that I should have "two positions on the small, two center and one big" going up? Are positions interval clicks?

I have been messing with the tension like mad and I'm still not happy- I either have difficulty getting into the biggest frong ring or have difficulty going down from the biggest to the middle ring.
 

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Ok I did more testing based off your suggestions Turtle- I put the rear in the middle ring.

Starting at the smallest front ring it take THREE clicks to get to the middle ring- which I can do if I push the upshift lever all the way, then one more click to the largest. I adjusted the tension so that it only took two clicks to get to the middle ring, but then it wouldn't come off the largest ring in only one click.

And that's where the problem lies- because I have to be able to get off the big ring in one click- the smaller shifter lever can only do one click when its on the largest front ring.

Sigh- I swear everything else looks good according to the instructions above, but I'm no pro- it looks like it's time to go back to the LBS- they sold me the bike- it should be rideable!!!

By the way I'm getting a lot of scoring on the insides of my front rings from the chain rubbing so much trying to upshift- is that bad?
 

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Well I feel a little sheepish, but it's likely something to be expected since I'm so new to road biking. The front derailer was too high- once the LBS adjusted it downward everything worked great. Of course it should have come like that to start, but oh well- hopefully everything is fine for my next ride. It's still three clicks to middle and one click to large on the way up and one to middle and two to small on the way down, but that's fine.
 
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