sticky shimano 105 rear shifter

i just bought a 2002 "never ridden" bike with shimano 105 groupo, however the rear shifter is "sticky" its tough to get it to shift up, it shifts down great but when i shift the smaller paddle it seems the brake lever follows and it does not catch. at times i have to hold the brake to the right with one finger and shift with the other finger.

the shop i bought it from says it will do that because its new ?!, i think its 2002 105 components.

1) do 105's have a history of bad shifting?
2) will it get smoother after a few more rides?
3) is there something i can adjust to rectify it?
4)does it sound like a dead shifter?

thanks greg

Try the easy fixes first.

105 generally shifts fine. One of the good things about Shimano is that its mid- and even low-level stuff works pretty well.
Have you looked at the system at all? Start by putting a drop of lube on the cable where it goes under the bottom bracket--sometimes that's all it takes. If that doesn't help, check the cable housing all the way from shifter to derailleur and make sure it's not kinked or crimped or anything (it won't be, but you have to check). Loosen the cable clamp at the derailleur and see if the cable slides smoothly in the housing. If not, pull the cable out and make sure it's not kinked, then either replace it (only about $3) or lube it and put it back in. You can find instructions at the Park Tool website (parktool.com, I think), or there are several good books you'll eventually want anyway. One is by Lennard Zinn, about $25.
Or just take the bike back to the shop and say, "I paid good money for this and it should work better than it does. Please fix it."

Just lube 'em!

gdugs said:

i just bought a 2002 "never ridden" bike with shimano 105 groupo, however the rear shifter is "sticky" its tough to get it to shift up, it shifts down great but when i shift the smaller paddle it seems the brake lever follows and it does not catch. ...
the shop i bought it from says it will do that because its new ?!, i think its 2002 105 components...

Click to expand...

My 1995 105 rear shifter started doing this w/in a year or two of bike purchase, especially on cold, humid mornings. At some point the front one also started getting finicky. I was told that they were failing and needed replacement. I put it off, and eventually, skimming the 'net, I found the solution at http://www.chainreactionbicycles.com/noisystilevers.htm - look near the bottom of the page. They currently recommend <u>flooding</u> with "powerlube" from an auto parts store, but I've had years (and many thousands of miles) of excellent results using aerosol Triflow about once every year or three. I think the open design of the 105 shifters makes them pick up dust and dirt (maybe even when hanging upside down).

The screw

There have been a number of forum posts about a small screw that can come loose and cause the two levers to stick to each other, and that the screw can be tightened without taking the shifter apart, something that should never be done. But I don't know if this applies to 105's. Take a look from the under side and see if there is an accessible screw (and we're still talking bikes here).

i found the problem

I found the problem I think

first I put in the post then I tried the suggestion of spraying some lube, that didnt work (i didnt just spray it i virtually immersed it in tri flow)

saw some screw messed with that, no difference.

then i decided to get serious, having taken apart many MTB gearing systems i was pretty confidant i could undo/redo what i was about to do.(still with me), and having never worked on a road bike shifter it was time i found out what made the baby tick (or click).i took off the cork and took everything off i could until i needed the "special tool", i made my own special tool and then reached the point where shimano suggested to go no further but there was no change in the functionality. male bravado and arrogance got the better of me so i took the plunge and ...

it was kinda tricky to get the "b" lever off , but it came off with a little jiggling and no force. at this point i looked to see what did what then i tried to put the lever back , no dice., but this is the point where i was able to see what the problem was.

there is a 270 degree return spring which returns the b lever rotator to the appropriate position, there was no tension on the spring so i removed it to re-tension it ...eureka this small piece metal dropped out (1 x 2.5 x 0.75 mm). this is the piece of metal that held the spring taught. on one side i could see it had broken off

then i inspected a while longer and decided i had passed the point of no return so... i popped the front name plate cap off and continued to dissassemble from the front. loosening two bolts and removing the brake lever, this allowed some play in the base center screw which made it possible to replace the "b" lever with ease

the time was 4:50 am and the mind started to get fuzzy so i decided to wait to re-assemble

my conclusion ( which could be false assuming i damaged the shifter on dissassembly)
1) the small metal piece is the culprit
2) if it works the same way as before (having to hold the brake lever back while shifting the b lever) with out the metal piece and spring, they were the problem
3)i am a jackass who lost any possible gaurentee on the part?

thanks for your help folks