Gearing problems...

[PartisanRanger]

I'm having a problem getting to the smallest derailleur (I think that's what they're called) on my road bike. I can switch between the medium- and large-sized ones without a problem, but whenever I try to switch from the medium to the smallest derailleur, I hear a strange cranking sound and it doesn't move down like I want it to. This has caused some problems on bigger hills, because I'm all but wiped out after pedaling in a high gear throughout. Sometimes it switches at the top of the hill long after I've hit the gearshifter, but by then it doesn't matter. What's wrong with my bike?

 

[John M]

I'm having a problem getting to the smallest derailleur (I think that's what they're called) on my road bike. I can switch between the medium- and large-sized ones without a problem, but whenever I try to switch from the medium to the smallest derailleur, I hear a strange cranking sound and it doesn't move down like I want it to. This has caused some problems on bigger hills, because I'm all but wiped out after pedaling in a high gear throughout. Sometimes it switches at the top of the hill long after I've hit the gearshifter, but by then it doesn't matter. What's wrong with my bike?

Your terminology is not quite right. The derailleur is the thing that moves the chain. You have a front and rear derailleur on most multi-speed bikes. Based on your description, it sounds like you are having a problem with the front derailleur moving the chain onto the smallest chainring (the large gears attached to the right side crank). This is may be due to a lack of cable tension such that the the first part of the shift lever movement doesn't actually move the derailleur as it should but rather just takes up the cable slack. The problem could also be due to maladjustment of the derailleur limit screws or malalignment of the derailleur cage.

You can probably fix this yourself, and I suggest consulting the Park Tool website or a good maintenance manual (such as that written by Lennard Zinn) for advice on how to adjust your bike.

http://www.parktool.com/repair/

You are not likely to damage the bike by trying these adjustments and if you are not successful, try taking it to a good shop.

 

[PartisanRanger]

Your terminology is not quite right. The derailleur is the thing that moves the chain. You have a front and rear derailleur on most multi-speed bikes. Based on your description, it sounds like you are having a problem with the front derailleur moving the chain onto the smallest chainring (the large gears attached to the right side crank). This is may be due to a lack of cable tension such that the the first part of the shift lever movement doesn't actually move the derailleur as it should but rather just takes up the cable slack. The problem could also be due to maladjustment of the derailleur limit screws or malalignment of the derailleur cage.

You can probably fix this yourself, and I suggest consulting the Park Tool website or a good maintenance manual (such as that written by Lennard Zinn) for advice on how to adjust your bike.

http://www.parktool.com/repair/

You are not likely to damage the bike by trying these adjustments and if you are not successful, try taking it to a good shop.

Thanks for the advice, man.
EDIT: The repair instructions seemed rather complicated, especially for a less mechanically-inclined person such as myself. Do you think my LBS (who I bought my bike from) is likely to adjust this for free?

 

[John M]

Thanks for the advice, man.
EDIT: The repair instructions seemed rather complicated, especially for a less mechanically-inclined person such as myself. Do you think my LBS (who I bought my bike from) is likely to adjust this for free?

If the bike is fairly new, they should adjust it for free or for a reasonably small fee if the bike is older. If the problem is any of those that I suggested, it should be a 5-minute fix for the shop.

 

[thombo]

If the bike is fairly new, they should adjust it for free or for a reasonably small fee if the bike is older. If the problem is any of those that I suggested, it should be a 5-minute fix for the shop.

I'm having a similar issue on my bike. I've already been in the shop twice to get the fron der tuned up -- it should definitely be free if you take it in and will only take 5 minutes. The issue it seems on new bikes is that the cables tend to stretch a bit (much like new guitarstrings that need to be tuned often right after they've been put on). I know it's a pain in the ass, i'm going through it myself, but I trust that it'll work its way out. I wouldnt try adjusting it yourself if you dont have a decent idea as to what you're doing.

 

[capwater]

If the bike is new, cable stretch is a definte possibility. Get used to tweaking your deraillers, check out www.parktool.com, it's really pretty simple. What's the worst that can happen? You end up taking it to a shop.

Nice UVA jersey on your avatar, you in C'ville?

 

[PartisanRanger]

If the bike is new, cable stretch is a definte possibility. Get used to tweaking your deraillers, check out www.parktool.com, it's really pretty simple. What's the worst that can happen? You end up taking it to a shop.

Nice UVA jersey on your avatar, you in C'ville?

Yep, and I'm a new member of the UVA cycling team. Not racing this year, though.

 

[artemidorus]

Cable stretch would make it easier to get on to the small chainring, not harder. Cable stretch is often the cause of new inability to shift to the big chainring, where previously one could.
It sounds to me as if the lower limit screw on the FD needs backing off a little, although there are other possible causes.
Less likely, the indexing is off a bit and you need to turn the barrel adjuster to shorten the cable sheath slightly.
I've never managed to bend an FD to the point that it couldn't be dialled back in through the above two methods (or adjusting the cable length at the derailleur, which I would fiddle with last).

 

[gclark8]

I find with most near new bikes the Low Limit screw on the FD needs to be readjusted before taking up a small amount of the cable slack.

 

[John M]

Cable stretch would make it easier to get on to the small chainring, not harder. Cable stretch is often the cause of new inability to shift to the big chainring, where previously one could.
It sounds to me as if the lower limit screw on the FD needs backing off a little, although there are other possible causes.
Less likely, the indexing is off a bit and you need to turn the barrel adjuster to shorten the cable sheath slightly.
I've never managed to bend an FD to the point that it couldn't be dialled back in through the above two methods (or adjusting the cable length at the derailleur, which I would fiddle with last).

Ah yes, thanks for noticing my error. You are right. I must of been having a bit of a brain cramp.