Skipping Gear

[GeorgeET]

Hi new user here. Need advice.
I fine tuned my bicycle Schwinn High Plains Aluminum Paramount design USA made MB, with Shimano 7 speed 200GS rapidfire shifters. Had the bike for 18 years and always worked fine. But had a clicking noise so I retuned front and rear derailleurs. (The noise turned out to be elsewhere)
But in doing this I discovered that my rear derailleurs shifts fine from smallest gear(outside) to the largest gear(inside) but shifting from the largest gear to the smallest always misses the third smallest gear and double shifts from the fourth gear to the second smallest. Just cannot tune that out.
Everything works good and is clean and lubricated. No Idea?? Maybe in the shifter itself? Thats clean and lubricated too.

BTW in looking at different sites for instruction I found this one to be the best.

[Alex Ramon]

If all your cables are lubed and working smoothly I'm thinking it could be a bent derailleur hanger. Here's video that shows how to repair it, but you'll need a special tool:

http://bikeride.com/derailleur-hanger-alignment/

The tool costs about $50, so you might be better off taking it to your local shop for a quick alignment.

[GeorgeET]

(04-11-2010, 03:34 PM)Alex Ramon Wrote:  If all your cables are lubed and working smoothly I'm thinking it could be a bent derailleur hanger. Here's video that shows how to repair it, but you'll need a special tool:

http://bikeride.com/derailleur-hanger-alignment/

The tool costs about $50, so you might be better off taking it to your local shop for a quick alignment.

Thanks for reply. I was leaning toward the shifter mechanism missing a detent. Shimano 200GS 7speed rapid fire. Checked your shifter overhaul info. Got about half way in but did not want to pull the cable out, so cleaned and lubed again. BTW be very careful with spray cleaners some like Barryman Carburetor cleaner is tough on paint. Not recommended with painted parts.

Tried adjusting cable barrel again and same result still missing one 3rd smallest sprocket on the way down, going up toward hub is OK. Weird.

Will look at derailer although I set that following Parks and your info and it looks OK.

[GeorgeET]

Hi Alex looked at your bent hanger video than looked at mine. Its a solid part of the frame about 3/8 thick, very strong and putting a straight edge against it does not show distortion. I think the derailer would break before the frame could bend.
But will take is to a bike shop for a looksie. I did all I can.

[Surly LHT]

It also could be your cable housing or your derailleur adjustment cable or it could be like Alex said too. Just go back over what all you have done and make sure you did it the right way its so easy to goof I should know have done it so many times until its not even funny. lol Good luck and let us know what you find out and how you fix it too.

[GeorgeET]

(04-11-2010, 04:42 PM)Surly LHT Wrote:  It also could be your cable housing or your derailleur adjustment cable or it could be like Alex said too. Just go back over what all you have done and make sure you did it the right way its so easy to goof I should know have done it so many times until its not even funny. lol Good luck and let us know what you find out and how you fix it too.

Thanks for advice guys took it to a bike shop and they confirmed that its as I suspected, the handlebar shifting mechanism is worn in that spot. It is the Shimano 200gs 7speed model.
He showed me replacement shifter units for both sides that come as set, these were the top mounted push pull units.Said the new stuff is not as durable.

He also looked over my 1992 Schwinn and said they do not make them as they use to I should hang onto the bike and live without one gear.

I agree unless anyone can recommend a suitable replacement or fix. Its a under bar two lever push push system. Thanks yoall.