Road Bike, Cycling Forums banner

1 - 8 of 8 Posts

·
Registered
Joined
·
32 Posts
Discussion Starter · #1 ·
I have a 2005 OCR 1, Giant bike with a Shimano 105 front derailleur that I can't seem to get adjusted properly. Should I upgrade to a better derailleur? If so, what should I get? I am very new to cycling, actually this is my first bike. So I am lacking knowledge. Thanks.
 

·
Beetpull DeLite
Joined
·
12,749 Posts
Derailleurs are one of the most uselessly upgraded parts on a bicycle. Unless the thing simply won't move, or you can't stand to have 10 extra grams on your bike, there's not point in buying a new one.

Basically they're "dummy" parts, doing only what the shifter tells them to do. So if you're having problems it's likely to be an issue with the shifter, or it's simply not adjusted correctly. Maybe the clamp isn't adjusted correctly, and it's not parallel to the chainrings? The 105 group has fine parts, so I really doubt the part itself is the culprit.

What's it doing? Post some more info on how and when it's misbehaving, and we'll try to help. If that doesn't work, take it to a bike shop.

Welcome to both the website and cycling in general...I hope you enjoy both!
 

·
Registered
Joined
·
32 Posts
Discussion Starter · #3 ·
There seems to be a few different things going on with it. First, it seems that the chain always seems to be rubbing against the derailleur, second, when you shift the derailleur never seems to move the same way twice. Sometimes it shifts fine, other times you need to try to shift more than once for the chain to move at all. It is parallel. Not sure if the shift line, not sure of the actual name, is too loose, or too tight?
 

·
Beetpull DeLite
Joined
·
12,749 Posts
cyclegirl said:
There seems to be a few different things going on with it. First, it seems that the chain always seems to be rubbing against the derailleur, second, when you shift the derailleur never seems to move the same way twice. Sometimes it shifts fine, other times you need to try to shift more than once for the chain to move at all. It is parallel. Not sure if the shift line, not sure of the actual name, is too loose, or too tight?
The cable (that's the shift line) might be too loose...they stretch after being installed. Unless this slack is taken up, then it'll shift funny. You can try this yourself if you want - use the smaller shift lever to get the front derailleur as close to the frame of the bike as it'll go, until it's over the small front gear. The cable should be somewhat taught...if there's any slack, then it needs to be taken out.

So if you have a 5mm allen wrench and a pair of pliers, try it yourself. Losen the clamp holding the cable at the derailleur using the 5mm allen key and, while pulling the slack out with your pliers, tighten it back up. Does this make sense?

Your shifter that controls the front derailleur has what's called a trim adjustment. Sometimes if you're in the small front gear and a small rear gear, the chain will rub on the front derailleur. So you can push the shifter a small amount and the derailleur will move a little bit - not all the way to the next larger front gear, but enough to get rid of the rubbing. Then, if you push a little more, it'll shift to the next larger front gear. Normally when you downshift to a smaller front gear, though, it'll jump one entire gear instead of the little bit.

If you're mechanically inclined and/or willing to learn, look into buying "Zinn and the Art of Road Bike Maintenance," it's a great book for the basics and more difficult repair. Or if you're cheap, check out http://www.parktool.com/repair/ for good tips and tutorials. There's a link there that'll show you how to adjust your derailleur. Remember, if you get it out of adjustment, it's nothing that a good shop mechanic shouldn't be able to fix.

If you're not, take it back to the shop you bought it from...they should give you at least a few free tune-ups. This is a standard thing that needs to be adjusted after time.
 

·
Registered
Joined
·
5,558 Posts
If you can't fix it by adjusting the cable tension I'd just start at the beginning. Undo the cable, then set the der to the right hight (about 2mm over the big ring when it sweeps over) and the correct angle (parallel to the c-rings). Then adjust the inner limit so it doesn't rub when you are in the big cog in back. Then attach the cable and tighten it. Then set the outer limit so it doesn't rub when you're in the small cog in back, but doesn't kick the chain off on the outside, either. Shift it a lot on the stand in ever possible combo to make sure it works. You may have to fine tune the cable tension from here but that's pretty much it. Go very easy shifting on the road the first ride to make sure it's working for you. The 105 front der is probably better than any Campy front der and 95% as good as the DA front der. And get the Zinn book as mentioned above.
 

·
Registered
Joined
·
32 Posts
Discussion Starter · #6 ·
Thanks for the help. I just ordered the book. I think I have almost fixed the problem, not quite though. There still is a tiny bit of rubbing. I will make more adjustments tomorrow. I have been at it all afternoon. Not quite sure how much longer I can sit on the bike. I just love the new bike though! :D
 

·
Beetpull DeLite
Joined
·
12,749 Posts
cyclegirl said:
Thanks for the help. I just ordered the book. I think I have almost fixed the problem, not quite though. There still is a tiny bit of rubbing. I will make more adjustments tomorrow. I have been at it all afternoon. Not quite sure how much longer I can sit on the bike. I just love the new bike though! :D
Good deal! It certainly sounds like you're willing to learn about the bike...that's the way to go. I don't trust anyone touching it but myself. Many everyday adjustments are very easy to make, and it's hard to really screw something up.

Glad you're enjoying it, don't hesitate to ask more questions on here at any point. Or, if you're bored (and a tad bit off mentally), take a peek in the Lounge...there's never a dull moment.
 

·
Registered
Joined
·
32 Posts
Discussion Starter · #8 ·
I will check out the Lounge. Thanks. I do lurk all the time, just never post. I am just getting into cycling, after running for years. I would love to get into racing and really need to learn as much as possible about this sport. Thanks again, maybe I will see you in the lounge!
 
1 - 8 of 8 Posts
Top