Bicycle Mechanics - 1989/90 Shimano/STI Shifters-Problems-Not shifting

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TheFlyingDingo
11-22-09, 02:40 PM
Got this bike yesterday, Planned on getting it for a while.
I was told it had shifting problems, didnt think it would be a big deal...still shouldnt be.

Supposedly this is the first series of Shimano STI shifters
They started out in the 1990s?

Now, With the rear shifter, It doesnt upshift...it downshifts and stays, in the last gear.
Im assuming its not catching, like the cable came undone for downshifting, or something came loose

And the front shifting, It doesnt stay...It will shift, but it doesnt "Stick"

Anybody else had this problem?
Any help, websites or information would be great

thanks in advance
http://i67.photobucket.com/albums/h307/t0rinoc0bra1971/20091122002231.jpgNot my picture...


operator
11-22-09, 02:45 PM
Those are not STI shifters.

Try flushing the shifters out with WD-40, congealed grease may be inhibiting the action.

TheFlyingDingo
11-22-09, 02:52 PM
Lemme go get a picture of the other lever...


Mike T.
11-22-09, 02:58 PM
Those are probably "Rapidfire" shifters. They could be gummed up inside and/or the cables gummed up. As the other posters says - spray the insides with WD-40 and give 'em lots of working back & forth, unhook the cable outercasings and lube the cables. Pu it all back together and make sure the cables are not too slack. The Park Tools website will show you how to adjust the cables and shifter indexing.

TheFlyingDingo
11-22-09, 03:00 PM
Ill try the grease thing out,
heres the pics
nothing about rapidfire on the levers

The bike is a 1989 GT Karakoram from the original owner
http://i67.photobucket.com/albums/h307/t0rinoc0bra1971/IMG_4415.jpg
http://i67.photobucket.com/albums/h307/t0rinoc0bra1971/IMG_4416.jpg

waldowales
11-22-09, 05:05 PM
I have a couple of bikes with those same shifters. There are at least two models that look exactly the same from the outside, but are a bit different inside. They both have the same problem, a small pawl or dog that gets gummed up and sticky. Remove the shift cable and the screw in the center of the pod, then pop the housing off. You'll see a couple of spring-loaded dogs inside. These will be sticky, or, rarely, the springs will be weak or broken. You may be able to free them up by squirting solvent or WD-40 on them and working it in, if not, you'll have to remove the small c-clip on the shaft and remove the pawl and clean it and the shaft, then re-lube with light oil or Teflon lube and reassemble.

Bianchigirll
11-22-09, 05:27 PM
Those are not STI shifters.

Try flushing the shifters out with WD-40, congealed grease may be inhibiting the action.

actually they are. they were the begining of STI aka Shimano Total Intergration. which was intended to force bike manufactures to buy complete shimano kits. the idea was to mount the shifter on the brake lever so you had to buy both and the SLR (Shimano Limear Response) was designed to make shimano brake lever work with shimano and only shimano brakes.

OH as for the bike. it looks like it needs alot of cleaning and unless you are handy around bikes a good professional tuneup

bbllaakke
11-22-09, 05:42 PM
Sometimes you have to actually take the shifter apart, spray wd-40 (or some other spray lube) on the pawls and work the pawls back and forth with an old spoke. This is how I've repaired them the three times I've come across them.

Jeff Wills
11-22-09, 05:52 PM
Those are probably "Rapidfire" shifters. They could be gummed up inside and/or the cables gummed up. As the other posters says - spray the insides with WD-40 and give 'em lots of working back & forth, unhook the cable outercasings and lube the cables. Pu it all back together and make sure the cables are not too slack. The Park Tools website will show you how to adjust the cables and shifter indexing.


+1. STI aka Rapidfire shifters from the early '90's. If they're not worn out, flush with WD-40, lubricate with spray lube, flush out the cable housings, replace the cables, reassemble and adjust. Go ride your bike.

I have a set of first-series XTR shifters from the mid-'90's that started missing shifts consistently. I sprayed lube inside, and they've worked ever since.

Svr
11-22-09, 06:03 PM
The bike is a 1989 GT Karakoram from the original owner


It must have been purchaced in late 1989 as an early 1990 model, or the shifters/brake levers were added later. STI didn't exist in 1989, it was introduced in 1990. You can try the cleaning/lubing procedure, but some of the earliest STI units had improperly heat treated parts in the ratchet assembly. These units wore out fairly quickly.

TheFlyingDingo
11-22-09, 07:11 PM
Well, The WD-40 did seem to work, Shot it in without taking anything apart. It still sometimes doesnt catch, but ill let it soak in and hit it again tomorrow.
The Front derailer still doesnt want to stick, ill have a look at that when i take the bike apart for cleaning.

As for cleaning the bike, I know my way around doing that, tips and tricks here and there...but still sort of learning the tuning...
ive only done BMX and Antique cruisers, so my knowledge varies

I think ive got it down though


Forgot to mention:
The original owner was in the military and bought the bike down south near the end of 89. So, yeah...90's bike...Same year as my car