how to replace this cable
 

For the life of me, I can't figure out how to get out this shifter cable:

http://i153.photobucket.com/albums/s...p/P1250372.jpg
http://i153.photobucket.com/albums/s...p/P1250371.jpg
http://i153.photobucket.com/albums/s...p/P1250370.jpg
http://i153.photobucket.com/albums/s...p/P1250369.jpg

Any help would be appreciated. I got a used bike for a Christmas present, and it looks nice for the most part. Just needs a little help.. cables being one of them.

If that doesn't work, I have a 6 speed grip shift on another bike.. what are the chances a derailleur and twist shifter from an old Wal-Mart mounting bike be able to be swapped over to a kid's bike?

If you cannot find an opening by peeling the rubber grip back, toss the whole thing.
they were made only for OEM installation and never to be serviced, but cheaper..

if you want it to click the brand of the shifter and the RD have to match
and have the same "speed" number.

Wall Mart product managers always choose cheaper
over serviceability after the sale..

There are no rubber bits.. it's all hard plastic. I was afraid it wasn't going to be serviceable after spending 1/2 an hour trying to figure out how to open it. Then I walked over to my Trek and peeled back the rubber bit I was looking for.

The Wal-Mart bike (a free parts bike) I have appears to be the same thing, but I can probably use the cables that are already in the shifter. They're both 6 speed rear freewheels, but one is a kids suspension bike with 20" tires, and the other is an adult mountain bike with 26" tires. Maybe the derailleur will swap out..

I guess it doesn't hurt to try swapping things, otherwise I'm out the $20 I spent for the bike. I guess it didn't occur to me that it wouldn't be replaceable. I suppose some thumb shifters wouldn't hurt as a last resort.

Loosen the allen bolt visible in the last picture. Slide the entire assembly inward on the handlebar (away from the rubber grip). Separate the "grip" part of the shifter from the body - you may need to twist it on way or the other - and this should give you access to the cable end. You may also find that that triangular shaped plastic piece is removable but maybe only if the grip piece is first removed.

I'll try this later tonight or tomorrow.. but the assembly in the picture is all one piece as far as I can tell. The "grip" part isn't a soft rubber, but a hard plastic.

So I gave up and pulled the twist shifters from another bike. It's a 6 speed freewheel too, but I think I'm going to have to swap the rear derailleur. I was hoping it would work, but sadly doesn't seem like it will happen.

With a 6 speed chain on a Wal-Mart type bike, can I break the chain and re-join with the same pin?

If it's similar shimano cheapness, you probably just need to adjust the cable, and assuming you can get the pin fully seated without pinching the links there to tightly, I see no problem with doing that.. but more experienced heads will weigh in I'm sure.

6 speed chains, even the Shimano ones, are wide enough that you can
just do your normal break and repin, to my knowledge. I specifically
stopped using the bastards when they got to the two or three different
colored replacement pin depending on chainwidth stage, because I had
a friend or two who did significant damage to rear D and dropout with
a moving fast chain separation using a Shimano chain.:twitchy:

8 cog rear is as much as I own, so not really an issue for me. With regard
to those twist grip shifters, In my lifetime at the coop, I've tried to recable
about twenty of them. I think I successfully managed two of the earlier
ones (came apart by loosening an allen set screw).

So try not to personalize it. I usually tell people if they want to go at it,
here's how it comes apart and there's where the cable goes, good luck.:thumb:

I don't waste my time recabling them honestly, the dump is plentiful with strippable cheap mtb frames, REI charges about 20 bucks for a set new as well, and of course there's always the odd scores, in terms of the grip shifters that it.

The replacement set from the donor bike allowed for an easy re-cable, so I was good with that. Just need to get the rear derailleur to match now, since it didn't seem to be compatible. Hopefully it works. Kinda sucks when you can't test ride a bike before you buy it because it's for your kid and too small for you. But looking at it, I knew it needed a new set of cables and it wasn't adjusted properly. Just didn't expect to run into disposable parts (I didn't know they existed).

They weren't meant to be disposable - they are just very cheap and difficult to service, so disposal and replacement becomes a preferred option.

Well, once I get this working I may disect one to figure out the proper way to replace the cable.

I still have a ton of grip shifters I do experiments with from that pile, haven't had success yet but mine are mostly trash, let us know how ya do.

SRAM uses a different pull ratio on some of their stuff (1:1 vs. Shimano standard of 2:1) so that may be the problem.

I think the method Gonzo Bob mentioned would be the way for that shifter.

Here's a video:

Yea, that seems to be the case.. I'm hoping I'll get to swap out the derailleur today or tomorrow.

On this particular shifter, there is no hole on the inside of the shifter as seen at 1:44. I tried pulling it apart before, but it wouldn't budge. My replacement shifters to look exactly like that though.

But have you discovered why the allen screw is there? It's not likely that it's a decoration. FWIW, it looks like the assembly where the cable enters may slide away from the twister; off the key-way shown in the first picture.

Oh, yes, I have some SRT-600 shifters that also do not have the "hole on the inside of the shifter". Aside from that detail, cable change procedure for them goes just like in that video, however.

Interesting unrelated to the task at hand tidbit: if you're really careful and lucky you can actually replace cables on the shifters in the video without shifter disassembly.

I've loosened both allen screws trying to take it apart. I know the one held it to the handlebar. Maybe I need to take the other one completely out to disassemble it. I'm planning to work on it this afternoon, so maybe I'll try that first. Although with where I'm at, swapping out the derailleur will be easier, and the replacement parts are in better condition.

There was no second allen screw on this one.. I was thinking of the replacement one.

Anyway, I can get it to shift from the largest to smallest or the smallest to largest perfectly with the current derailleur by adjusting the cable tension, but not both. I'm guessing that with this being a kids bike, something might be bent with the rear derailleur, but I don't know what to look for. Suggestions?