Shifters not grabbing after 2nd, problem inside shifter not derailleur/cable tension

[thedarlington]

hello i have some shimano rapidfire shifters which you push for every next gear, it shifts 1 and 2 fine, but after 2 it just loses tension and doesnt wanna grab and pull the cable to the 3rd front gear, its like its not grabbing anything because the cable isnt that tense, i can pull it easily with my hand, right now i have it with wire ties on 3rd, any advise would be appreciated

[nfmisso]

more information about the bike is needed.

I would inspect the cable, and probably replace it.

[trevgbb]

there are several varieties of Rapidfire, see this;
http://techdocs.shimano.com/techdocs/index.jsp;jsessionid=ywfLTvdQxLvwgPThbLL8Xh1VYtGjKvvgpDhxTvtwShbktywlSV9Z!122806​1637
and select the si-number to suit your levers for set up instructions.
You can also try unclamping the cable from the changer and holding it at the end to give tension, operate the shifter.
Also operate the changer by hand to check if it is giving full travel.
This should tell you if the problem is with the cable, the changer, or the shifter.
You can also watch this;
http://bikeride.com/rapid-fire-shifters/

[bikesculptor]

I had this happen to my Bianchi mountain bike after several months of non-use (winter). Basically, I needed to free up the mechanisms within the shifters. My mechanic sprayed Tri-Flo (not WD-40!) into the shifter and clicked through the gears rapidly several times. He suggested a long ride with lots of shifting to fully loosen it up. This fixed the problem for almost a year. It may recur, but Tri-Flo in the shifters should take care of it.