Broken trigger shifter :(

Mr.Duck

My rear trigger shifter is broken (SRAM X-5 on a Carrera Gryphon). I couldn't select gears lower than about 5th. I examined the shifter and found the plastic housing was cracked open near where the cable enters the shifter. I don't really know what to do with it. If I need to buy a new shifter, can I get a different make/model? Something low cost and high reliability if possible. Any advice and help would be much appreciated.


EDIT: So I checked it more carefully. The cable runs through this little plastic thumb screw thing and a tube with thread on the outside of it, which then this screws into a plastic part which should be attached but has been broken off the main body of the trigger shifter. But the broken bit does sort of sit in place, so maybe I can salvage it?

The triggers feel awful. Clicking up, the dial moves maybe a few and then the trigger would stop. Being way too hard to move it even a little bit. While all of this is going on, the rear mech is not moving anymore (I used to be able to change gears a bit). I pulled on the gear cable on the downtube and it moved the rear mech well. Fairly smooth and free accross the whole range of gears.

The Rookie

Rmove shifter, rmove cable and try and glue the broken piece back on, reassemble.

You can replace with any SRAM Xx (where x is a number) shifter of the right number of speeds.

Mr.Duck

Thanks for your help.

So I took out the allen bolt and tried taking the shifter off the handlebar. It came loose but I couldn't get it off. Was I supposed to take off the handlebar grips first? I stupidly forgot about taking out the cable. I just glued it with a super glue gel with the cable still in and the shifter still on the handlebar. A bit stressful after standing there holding steady it for a while and finding it wouldn't stick. But I left it alone and it seems to be working . The glue has set hard. I am going to give it a second coating of glue tomorrow. Filling in all the little gaps and cracks that were not filled on the 1st pass. Hopefully it will work. I'll be pretty pleased if it does work .

The Rookie

Mr.Duck wrote:

Was I supposed to take off the handlebar grips first?

Yes it slides off the end!

Mr.Duck

ok :oops:

Well it's got a whole bunch of glue on it now. It's looking really solid! It still hasn't dried completely after many hours of drying, so I will leave it overnight again.

So tomorrow I will try to screw the threaded part back in to reassemble. There is this little plastic thumb screw thing too. Do you know what I should do with that, like turn it clockwise or anti-clockwise all the way?

Mr.Duck

The glue has worked! It feels solid. I've put it back together. The threaded part I put it all the way in pretty much, which is how it looks on the left shifter.

The gears are still not working though. I can press the trigger shifter to select 1st on the display, but it the chain doesn't go any higher than the 5th cog. And on the shifter, as I change up through the gears, it goes up to about 6th on the display, then feels loose and doesn't go any further. As I press the trigger, nothing happens.

Is the next step to take the cable out of the rear derailleur to pull it tighter? I want to check first incase I screw it up...

Mr.Duck

I've very nearly fixed it...

I adjusted cable and the limit screws. So starting out on the smallest sprocket, I can click through all the gears on the shifter, all the way on to the largest sprocket. Whoop. When changing back, it goes through all the gears again but it gets stuck on the second smallest sprocket . I can hear it clicking, like it's trying to change on to the smallest sprocket. If I move the derailieur by hand, it sits on the smallest sprocket ok. I also found if I twang the gear cable on the down tube (the cable feels fairly loose BTW), it helps it get into the small sprocket.

What would cause this? Do you know what I should try next?

The Rookie

Could be
1/ sticky cable
2/ sticky mech pivots
3/ Low stop screwed in a fraction to far.

davis

You might be able to fix this simply by slackening off the rear cable adjuster by an eighth of a turn or so! But....

Have you replaced the cable inners? I'd also look at replacing, or at least trimming, the cable outers. The rear mech cable tends to get filled with crap on its final loop from the chainstay to the rear mech. Hopefully they're initially left long enough to be trimmed (about 2cm off each end) so they're left clean. Do it with a pair of cable cutters (not pliers!) or a Dremel so that you don't squash the cable outers. The always-useful Sheldon Brown has a very thorough page on this.

Replacing the cable will probably mean adjusting the indexing all over again, but you're nearly there and it'll get a hell of a lot easier to diagnose these things to the single thing that's the problem, and you're well on your way to fettling independence.

PS I think The Rookie above means "High-stop" rather than "low stop" above...

Mr.Duck

Thanks for these ideas. It is helpful.

Ya, he means high-stop, but I understood what he meant

I gave the derailleur a light lashing of GT85. I tried to work it into the joints. This didn't fix it completely, but it helped for sure.

The cable is really quite slack on the downtube, so I think it's getting sticky in the final loop from the chain stays as you described. Because it is SRAM, the cable joins at the top of the derailleur, then runs throuh a little guided track around the back (exposed) to another part of the derailleur to be clamped. I think this is creating extra chance of sticky cables and problems. Plus it means the cable outer is really short so I can't cut 2cm off each end. Compared to Shimano, which looks more simple and reliable, and would have been long enough to trim the cable outer because it loops round the outside for quite a long way.

New cables and cable outers would be the next step. But I will leave it alone for now because it's just about working as it is (plus I don't want to break it :P), and I'll try to wait till I have a bit more experience and confidence in what I am doing when I do try it. When I do try it, I could use a Dremel to cut the cable. Not sure how bad the melting would be from the high RPM on the Dremel. It's briefely mentioned on Sheldon's site, but doing it yourself is where the learning comes for this sort of thing. Or I could just buy cable cutters... Oh and do you guys go for Teflon coated cables, a few drops of chain lube, or anything specific you like to do?


Oh, and a quick question not too off topic... I saw another bike with 2 lumps of something at both ends of the derailleur spring. It looked like some waterproof grease. It looked like it was never going to dry out. What is that stuff? Does it have a special name like marine grease as opposed to lithium grease?

davis

Mr.Duck wrote:

When I do try it, I could use a Dremel to cut the cable. Not sure how bad the melting would be from the high RPM on the Dremel. It's briefely mentioned on Sheldon's site, but doing it yourself is where the learning comes for this sort of thing. Or I could just buy cable cutters... Oh and do you guys go for Teflon coated cables, a few drops of chain lube, or anything specific you like to do?

Don't worry about melting. Some people *cough* have been known to grind the cable outers down because it gets them smooth and flat (you have to poke a sharp point in the hole immediately afterwards to make sure the plastic lining sleeve doesn't fold over inside). If you've got a Dremel I'd just use that, as decent cable cutters (Park make the only cable cutters that haven't immediately folded up in my hand!) are about 20-odd quid.
I've been known to wipe grease along the cable inner with a rag before threading the cables, or spraying GT85 on it maybe. Honestly it's not really worth the effort; you get way more difference from a new cable.

Oh, and a quick question not too off topic... I saw another bike with 2 lumps of something at both ends of the derailleur spring. It looked like some waterproof grease. It looked like it was never going to dry out. What is that stuff? Does it have a special name like marine grease as opposed to lithium grease?

Lithium grease is totally fine to use; I got a big pot for not much money. You can spend an infinite amount of time and money trying different greases (especially if you start chucking words like "marine" around; that's a price-doubler right there!). Honestly they're not hugely different for our purposes. We're not building spaceships. There will be someone along shortly to explain exactly why I couldn't possibly use a specific grease on a specific bit otherwise it'll asplode immediately, but sooner or later I just want to ride the damn thing. Making sure threads aren't covered in swarf is more important than exactly what flavour grease you spread on your toast.

Mr.Duck

I thought lithium grease could dry out? So you could use it on sealed parts like to lube ball bearings, but not on more general purpose things like pivots. Maybe I got that wrong, I've never used the stuff.

I have found a cheap source of lithium grease if anyone is interested (£3.50 for 500g)... http://www.wilko.com/car-maintenance/co ... vt/0039759

The Rookie

Lithium grease does dry out and it's the best for shifters.

Red rubber grease is waterproof (used for boat trailer wheel bearings) and very gooey....