RD adjustment ?
 

so, my RD to a bit of a hit the other day when I fell over, i've got it pretty well adjusted at the top and bottom but on the 3&4 cogs (21t and 19t) it seems to want to skip around a little and not drop into gear well. 27t is reasonably quiet and it isn't shifting into the spokes, same goes for the 12t and the frame, doesn't matter which ring I'm in, same result. any insight on this??

Your derailleur hanger is very likely not straight any more. You can get it to shift perfectly on some cogs but never on other cogs, and you won't be able to fix it with just cable tension adjustment alone. You can eyeball it and bend it back very carefully, but your local shop probably has a special alignment tool that will let them bend it back closer to straight than you doing it just by eye. Make sure you tell the shop that your bike fell on its drive side and that's why you want the derailleur hanger straightened until the shifting is decent again...

cool thx!!

Not all derailleur hangers can be bent back into alignment and if they can't, you shouldn't try. If it's replaceable, you may need a new one.

Take it to the shop, have them look at it. If it isn't the hanger, I'll eat my [STRIKE]hat[/STRIKE] helmet.

lbs tells me about 20-25 bucks for a replacement

If that's the price for a new hanger and installation, that's a deal.

qft

nope, just hte hanger

anyway, ordered one from derailleurhanger.com cuz PerfBike wasn't very helpful and it was pretty damn tough to find the one I needed, apparently the Apex equipd GT Series2 has a slightly different frame than the standard 105 bike listed in the GT archives and required a different piece. after much looking around I finally got it, $33 to my door, I'll install and adjust myself.

should fix me right up. thx guys

+1 the lbs i used to work at would charge around $35 for that..i'd get it done

hanger showed up, had to use a dremel to get the fit exact, didn't even have to adjust the barrel nuts, cleared everything up perfectly. thx guys!

Thank God I don't have to eat my helmet!

In my experience, if the limits and tension are adjusted properly, the hanger must be totally and obviously way tweaked for it to affect shifting. Sounds more like a cable issue or friction in the RD itself to me. Personally, I'd verify adjustment and free movement of the RD and cable before taking it in.

Good on ya, bonz.

This is often my experience, too, so many times that I don't even bother making adjustments until I remove the derailleur and make sure the hanger is straight. Five minutes of prevention beats twenty minutes of farting around with cable tension and limit screws on a derailleur on a bent hanger. It's such a time saver, the service is included in the cost of the derailleur adjustment.

seeing that I'm fairly new to most things related to these kinds of issues I have to give props to the 41 for help. I'm, at times, insufferably cheap, I hate paying someone to do something that I'm perfectly capable of doing with a little education and effort. sure you gotta sort thru a fair amount of sniveling and bs around here but for the most good info here and good people.

thanks again!!

Looks like its all covered.

Just wanna add, if in doubt, if the hanger is bent (in). Do NOT shift to the easy gear on the cass. :thumb:

( ...and if you order a new hanger on line, you might not have to adj anything on the rd after repl the hanger... assuming it was adj correctly, AND no one touched the limits after the accident. )