Rear gears not working

dcini

I have Shimano changers on my Trek. While someone else was riding he was shifting rear gears and when he came to the biggest rear sprocket the shifter wont shift to any smaller sprockets anymore. I have a thumb shifter. I tried to check derailleur and looks good. I opened the shifter and all seems to be good, but when you try to shift down gears it wont work........as if the spring is not pulling it back. I tried to spray it. Still no good. Time for a new shifter or is there something i am not seeing? Any advice before i just go and buy a new one? Thanks

nicklouse

Change the cables both inner and outer.

larkim

DIsconnect the cable at the derailleur end and make sure that the mechanism falls back to the smallest socket when pushed into the wheel (and released). You say you've "tried to check" the rear mech, but what have you done?

Suggestions about cable replacements always a good idea, but would it be reasonable to expect it to just seize up one day?

dcini

Thanks for your replies. I did check the rear mech and it falls in place without any problems. That is why i suspected in the handlebar shifter. I didnt check the cables though. I will try that first. Thanks

dcini

It was in fact the cables. Too much drag. Changed them and as good as new. Thanks once again