I really think it might be the shifter. I have one that *will not* go into the top cog in the rear without holding it (and sometimes not then). Very frustrating - but a mechanic I trust told me that I would have to replace the shifter - so I'm living with it for now (it's not the bike I do climbing rides on).

I'm not from your area, so I can't help - but hopefully someone will chime in with a rec It can be *so* frustrating to try to find a shop you trust and who fixes your bike correctly.

CA