Rapid shift gears losing tension

[bikerepair12]

Hello all.

I’ve got an issue with my shimano gear shifters on my specialized mountain bike. It’s got the rapid fire shifters.

When shifting down from 9 there is full tension until you get to 6 then the lever loses all tension and won’t go any further down. there doesn’t seem to be any bite there at all.

does anyone have any suggestions on what this could be and how to fix it please?

 

[Paulus]

Either the rear mech is sticking so not pulling the cable through, or the cable is sticking in the inner because of corrosion or it is fraying.
Undo the cable clamp at the rear mech and see if the mech is moving freely by hand, and also see if the cable is moving freely.
A picture or two of the rear mech and cassette might shed some light on the problem.

 

[Cycleops]

Is the shifter quite old? If it is they can very often get gummed up with dirt and old hard grease and a good flushing with WD40 or similar will clear so try that and the suggestion by Paulus as well.

And to the forum.

You might find this usefuL:

View: https://youtu.be/yANmZfVYMOk

 

[Windle]

Hi there and welcome to the forum from a recent joinee .
I had a very similar problem with the Shimano STX shifter on my old Univega (though only 7 speed), which I bought from a second hand shop last year. The highest four gears would work fine with plenty of tension in the thumb lever ~ then nothing, the first time it happened I thought the cable had snapped. I eventually tracked it down to a tension spring (like a big watch spring) that was keeping the thumb lever tight, it was attached to a washer type plate that slotted over a square post and was 90 degrees out, thus too slack. Since I moved it round it's been OK. When the lever loses tension try easing it back slightly, this seemed to bring the tension back with mine, though only for the next gear then it went slack again. Let us know how you get on.