Bicycle Mechanics - Shimano Shifting Weirdness

I have a 1995 Diamondback Sorrento (an oldie, but goodie) and I'm having some shifting problems with it. I've tried adjusting cable tension, and the low-high range on the front and rear derailluer, but it doesn't do anygood. On the FD, I've got gears 2 and 3, but no 1. On the RD, I've got gears 5,6,7. Trying to shift into any other gear is weird, because the shifters act like the gear doesn't exist - when pushing or pulling the levers, there is no resistance or click or anything, just nothing. Any ideas?

Thanks in advance.

I have a 1995 Diamondback Sorrento (an oldie, but goodie) and I'm having some shifting problems with it.

What shifting components does it have? I have a 1994 Diamonback which is loaded with Shimano MC-30 STX. I assume your '95 DB might have the same.


On the FD, I've got gears 2 and 3, but no 1. On the RD, I've got gears 5,6,7.

Last year my DB started to refuse to pull the FD over to the biggest chainring. I had 1 and 2 but not 3 (which I almost never use).


Trying to shift into any other gear is weird, because the shifters act like the gear doesn't exist - when pushing or pulling the levers, there is no resistance or click or anything, just nothing. Any ideas?

I opened up a used MC30 STX shifter that had the same problem as mine. There wasn't anything broken or worn out. It simply was dirty and gummed up - the shifting pawl wouldn't swing out enough to engage any ratchet teeth. I think a good cleaning and lubing should fix them. From what I remember, the shifters can be opened up via two screws.

+1, flood the shifters with WD40. Work the mechanisms until it frees up.

They are Shimano Altus ST CT 90 shifters. I flooded them with WD40, and it didn't seem to change anything. I opened one of them up, and I think one of the ratchets inside may be broken. Are shifters hard to swap out? I really like the bike frame and the way it rides, but I'd like to be able to shift. :-) There is a repair shop in town - how much do you think they'd charge for a set of new Shimano shifters and installation? I don't want to get ripped off - maybe you folks could tell me what that'd run.

Thanks so much everyone!

http://img55.imageshack.us/img55/2608/altus.jpg

I'm not clear on how many gears you have - 7? 8? Anywho - when my Shimano Deore shifters went knutz on me, I bought the Shimano-compatible SRAM Attack shifters. Not too expensive ($50) and work flawlessly. You may encounter a problem finding 7-spd. shifters though. Ever consider going up to 8-spd*. or 9-spd? Those you can find easily.

* This is assuming you do have 7-spd.

The 7 speed Altus shifters are available but are scarce. You will get new shift cables and housing with them at a cost of $35.00. You should replace your brake cables and housing while you're at it as well as the brake pads which are undoubtedly hard and working much less effectively. You'll be pleasantly surprised how well your brakes will work w/ new pads.
I'm a bike shop mechanic and just did a performance tune on 2 matching Diamondback Sorrentos yesterday; replaced the shifter pods, complete cable/housing replacement along w/ brake pads. The bikes work as good as new.
You might want to take the bike into your LBS for a complete tuneup. Surprisingly affordable and the work will be done properly by experienced mechanics.

It's configured like a 21-speed right now (7x3). Are those hard to come by these days? I have an appointment with the repair shop in town this afternoon. Hopefully they don't bilk me out of major dough. I wouldn't like to spend more than $100 - $125 total. The shop in town mainly deals in Salsa and Surly mountain bikes, but told me they'll be able to help me as well. I imagine shifting components are similar across bikes - Shimano and the other brand I can never remember.

Thanks everyone for your help!