casey86

My mountain bike is under warranty still and the first left gear twist shift stripped out so I got a new one from the company and installed it. The same day the rubber grip part of the twist shift came loose and now I have to squeeze it tight with my hand to switch gears and it won't go above about the first 4 gears because its too tight. What happened? Is this fixable or is the twist shift ruined again?

ChrisM2097

Sounds like either really cheap parts, or someone didn't install and/or adjust it correctly...or both. Normally the left-side gear shifter controls the front derailleur. Normally there are no more than 3 front chain rings. I'm a bit confused when you say that the left gear shift won't go above the first 4 gears - when it should only have 2 or 3.

What bike? What components? Make & Model #'s may help.

If it's still under warranty, and it's still not working correctly, absolutely keep taking it back until it works to your satisfaction.

casey86

It is a 21 speed Mantis Ghost mountain bike. I installed it correctly using step by step instructions. It is cheap parts. Its just a department store mountain bike. I just need to know if I can just glue the grip back on and it'll be fine or what?

ChrisM2097

In your original post, you said that the shifter "won't go above about the first 4 gears". If you're talking about the left-side shifter, then the wrong part was installed. Since your bike is a 21-speed, the left-side shifter should only have 3 speeds, and the right-side shifter should have 7. It definitely wouldn't look right, though, as the shifter would have had to have been installed either backward or upside-down.

Maybe a couple of photos, or a better description of exactly what's going on will help us diagnose the problem.

If it's not too late, see if you can return it, and then maybe buy an older, higher-quality bike on Craigslist for about the same amount of money.

casey86

Here is the left shifter. The rubber grip to the left of the white dots is loose now.

ChrisM2097

OK, that makes a little more sense. The white dots are not indicators as to what gear you're in, they're basically just white dots. As for the reason why you're not able to shift all the way from "L" to "H" - it likely has to do with the stops (small screws) on the front derailleur. Taking the bike back to Wal-Mart or Target, or where ever you got it, to get repaired will probably be a waste of time and energy. Search Youtube for videos showing "how to adjust a front derailleur".

As far as the rubber portion of the shifter coming loose...maybe it can be glued. Maybe it's simply poor materials, design, and assembly. Maybe closing the gap between the grip and the shifter will help. It's really hard to say. I would say try a little bit of hair-spray inside there to see if that helps. I use it on slip-on grips, and it holds real well for a long time.

In my opinion, grip shifters just plain suck, and I've seen far too many of them fail. I'd much rather have a set of indexed trigger-type shifters.

casey86

I bought it from Amazon.com about 4 months ago. I've done too much work on it to be able to send it back. The company that built it has sent me replacement parts for it from their online warranty system so that has been very helpful. They just sent me this new shifter and I hope it isn't broke. The gap between the grip and the shifter can't be closed unless I put something there because thats as far as the hand grip will go on it. So what about those screws keeping me from going from low to high all the way? Am I doing something wrong or is this normal?

ChrisM2097

The gap can be closed by moving the shifter to the left. Just loosen the set screw (I think it should be a 3mm allen screw).

The screws on the derailleur should look like this (High Stop / Low Stop):


These screws are adjusted to properly align the chain with the chain rings. If they're not adjusted correctly, either you won't be able to shift into one of the gears, or your chain will end up falling off when you shift.


Watch the entire video, and pay attention to each point discussed so that you fully understand how each part of the derailleur should be adjusted.

fietsbob

Left is running FD there are max of 3 different chainrings.

maybe you are trying twisting it into infinity when infinity does not exist.
there are limits..

those 2 stroke limit screws.

PHT

Those are the cheapest of cheap grip shifts and as has been mentioned most people say grip shifts are junk anyway. Having worked with those before I would say to not even bother with hair spray and move right on up to 3m spray adhesive if you want those rubber 'grips' to stay on the shifter body.

casey86

Thank you all so much for the very helpful replies. I was worried I stripped something out in the shifter grip. So I just need to apply an adhesive and adjusts the front derailleur properly according to the video and this should be ready to go. I wonder what was holding the grip onto the shifter before? You guys are right. They don't feel like a proper piece of bike equipment. Thanks for the help.