Bicycle Mechanics - Shifter problem on '93 mtb

I've got a 1993 Diamondback Ascent that I use for commuting. The bike is in pretty good shape and, believe it or not, still has almost all of the original components. One problem that I've had with it for as long as I can remember is that the front shifter will not push the chain fron the middle to outer chain ring. The shifter itself does not seem to have another position for this outer ring. They're pretty crummy Shimano Atlus A10 indexed shifters with integrated brake handles that came with the bike, so I've thought that perhaps with age something in the gearing of the front shifter broke and it no longer can shift to that position. That, or Diamondback put a double shifter on a bike with a triple crankset (which makes no sense). Anyway, I've tried making every kind of adjustment I can think of to the FD itself just to rule out that possibility (limit screws, cable tension, etc), but to matter what I do I can't escape the fact that there still does not seem to be a position in the front shifter for the outer ring. Has anyone else ever experienced this? Is there an easy solution that I'm missing?

I'd like to replace the shifters with something at around the same level, and I was thinking that the current Shimano Atlus (model ST-EF29) shifters would work well with the 7 spd setup that's already on the bike. One question I have here is will the integrated brake handles on these new shifters work with the older type center pull cantilever brakes that are on the bike already, or would I have to switch out the brakes for the v-brake type?

I've always like this bike a lot and would like to get it back in better working order, so thanks in advance for any advice :D

The cable pull on linear V-brakes is different than for the older cantis so you will need either a travel agent to modify the pull or switch out the brakes.

Thanks for the brake advice. That's sort of what I figured, but it's good to have some feedback.

Is it possible to just change out the front shifter pod without having to remove the entire front shifter/brake? Can you still get a shifter pod for a 13 year old Shimano Atlus shifter?

Is it possible to just change out the front shifter pod without having to remove the entire front shifter/brake? Can you still get a shifter pod for a 13 year old Shimano Atlus shifter?

I know Shimano used to make shifter pod mounts that would allow you to remove the shifters off the integrated mounts on ST-M class integrated brake/shifters and mount them independently but I don't think those would work for ST-EF style units. And I don't recall Shimano ever making pod mounts for that design of shifters.

When you have the cable detached from the FD, how many clicks does your shifter have? A common problem is that the palls will not catch the ratchet teeth. They need to be cleaned/lubed.
Even if the pod does detach, it will be hard to find alone. However, you can probly find some 3x7 shifters with canti brake levers. They can also be found seperate, especially grip shift.

I figured it would be a long shot on the shifter pod. The model number on the original shifters/brake levers on the bike now are ST-AT10, and I'm betting Shimano quit making those a long time ago.

I imagine I'll get better performance if I just go ahead and change out the shifters and brakes. Any advice on which model I should get (besides the newer Altus mentioned in my first post)? The bike has a triple crankset with a 7 spd cassette which are still in decent shape, so I would want something that would work with that setup.

I thought V-levers pull more cable -so would work on canti's.
Not the other way around.
?

CBolt, when I have the cable detached from the FD the shifter still only has one click. I've taken the covers off the shifter and I can't see any obvious signs of damage or corrosion either. I'm not sure what palls are, or how to go about lubricating this thing, but am open to hear any advice you have.

CBolt, when I have the cable detached from the FD the shifter still only has one click. I've taken the covers off the shifter and I can't see any obvious signs of damage or corrosion either. I'm not sure what palls are, or how to go about lubricating this thing, but am open to hear any advice you have.

Pawl =ratchet.

"mechanical device that permits motion in one direction only. The ratchet is usually a wheel with slanting teeth. The pawl is a lever tangential to the wheel with one end resting on the teeth. When the wheel rotates one way, the pawl slides over the teeth; when the wheel rotates the other way, the pawl catches in the teeth."

Pawls are in your rear hub.

As long as you're upgrading, you might want to consider going to 8-speed. At this point, it's only a matter of a new cassette (~US$20).

http://www.bikemannetwork.com/biking/p/COMPCASS8MTN/FW8100

And optionally new chain (~US$15) since you really should replace your chain along with your cassette.

http://www.bikemannetwork.com/biking/p/COMPCHBRSRAM/CH1055

I'll bet you can find 8-speed parts more easily and there probably won't even be much of a cost differential. Another thing you might consider doing is to try and remove your old shifters from the integrated set and just buying new shifters in pods. This way you can still run with your old brake levers and canti brakes.

Check out the SL-MC line of shifters...

http://www.bikemannetwork.com/biking/p/COMPSHMTNSETSH1/LD8884
http://www.bikemannetwork.com/biking/p/COMPSHMTNSETSH1/LD8750


If you want to go for the integrated solution again then consider the ST-MC20.

http://www.bikemannetwork.com/biking/p/COMPSHMTNSETSH/LD8756

But again, if you change brake levers then you'll need to convert to linear pull brake arms too. Shimano BR-M420s should run you around $12 per brake.

http://www.bikemannetwork.com/biking/p/COMPBRKLP/BR7572
http://www.bikemannetwork.com/biking/p/COMPBRKLP/BR7573

I thought V-levers pull more cable -so would work on canti's.
Not the other way around.
?

Well... it will certainly work better than the other way around but I'm still not sure it will be satisfactory. A linear pull lever will pull more cable but does so with less mechanical advantage... force. The mechanical advantage in a linear pull system is multiplied at the brake arm. Cantilever brakes on the other hand have a lower mechanical advantage so what will happen when you couple a linear pull lever with a traditional cantilever is that although you will be able to get the brakes to contact the rim, you won't be able to apply much force.

Well... it will certainly work better than the other way around but I'm still not sure it will be satisfactory. A linear pull lever will pull more cable but does so with less mechanical advantage... force. The mechanical advantage in a linear pull system is multiplied at the brake arm. Cantilever brakes on the other hand have a lower mechanical advantage so what will happen when you couple a linear pull lever with a traditional cantilever is that although you will be able to get the brakes to contact the rim, you won't be able to apply much force.

Interesting, thanks. You explain things well.
Mechanical advantage...the lever.. long would work better than short\2 finger levers?

the lever.. long would work better than short\2 finger levers?

That's a personal preference. Long levers usually don't have any kind of internal cam-action to boost the mechanical advantage since they don't need it as there's enough force being applied due to the longer moment arm of the lever. But two-finger levers have some sort of cam to increase the force. Shimano also had something called Servo-Wave levers which modified the cable pull and force depending on where you were in the lever throw. It basically pulled more cable initially and with less force but then switched (via a stepped cam) to pulling with more force but less cable as the pad contacted the rim.

khoun, I think that SL-MC line of shifters is the easiest answer to my problem. Thanks for the advice on upgrading to an 8 spd cassette. Considering how inexpensive that is to do I'm going to make that my weekend project one of these days. Thanks again!!

khoun, I think that SL-MC line of shifters is the easiest answer to my problem. Thanks for the advice on upgrading to an 8 spd cassette. Considering how inexpensive that is to do I'm going to make that my weekend project one of these days. Thanks again!!

Again, before you commit to buying the shifters, make sure you can cleanly detach your old shifters from your brake levers first. I know that with the "pure-mountain" (LX, XT, XTR) brake/shifter combos, removing the shifter unit left you with just a mounting hanger that could be easily removed with a dremel. I think the lower end groups are more tightly integrated into the same housing and you may be left with lots of artifacts hanging around that could prevent you from properly mounting or positioning your new shifter pods.

An LBS should be able to get just whatever you need. 7-speed EZ-Fire shifters are available individually for the left and right sides only, with or without brake levers, and V-brake or canty compatable. The only drawback is that they probably won't exactly match what you have on the other side.

You cannot upgrade to 8-speed just by changing the cassette even if you use 8-speed shifters. The 7-speed freehub body on your current hub is too narrow for an 8-speed cassette. You would have to change it for an 8/9-speed freehub body (they are the same) and have the wheel respaced and redished.

Given the age of your components and the questionable condition of the rim by now, it might be better to buy a new 8/9-speed wheel.

If you have to replace the shifters anyway, you might as well go all the way to 9-speed.

As long as you're upgrading, you might want to consider going to 8-speed. At this point, it's only a matter of a new cassette (~US$20)...
And optionally new chain (~US$15) since you really should replace your chain along with your cassette.

He'd also likely need a new cassette body for his rear hub. I bet his is limited to 7-speed. This would require re-dishing too. Check out "Body Transplantation" at the bottom of this page: http://www.sheldonbrown.com/k7.html

edit: HillRider beat me to the punch.

Again, before you commit to buying the shifters, make sure you can cleanly detach your old shifters from your brake levers first. I know that with the "pure-mountain" (LX, XT, XTR) brake/shifter combos, removing the shifter unit left you with just a mounting hanger that could be easily removed with a dremel. I think the lower end groups are more tightly integrated into the same housing and you may be left with lots of artifacts hanging around that could prevent you from properly mounting or positioning your new shifter pods.

I've been able to detach the old shifters from the brake levers quite easily. They're held on with only a 5 mm hex screw and come off quite cleanly (no artifacts left hanging around). In fact, the mounts for the shifters on the brake levers look exactly like the handlebar mounts on the 7 spd shifters you sent the link for:

http://www.bikemannetwork.com/biking/p/LD8750

If you take a look at the picture of the shifters on this website, the shifter mounts that are a part of my current brake levers look just like the silver colored handlebar mounts in the picture, except of course that the ones pictured don't have brake levers attached. I figure I can take off these silver colored mounts pictured from these new shifters and just attach the new shifters themselves to my current brake levers. It would be nice if I had some exact measurements for the new shifters, like the diameter of the new shifter mounts so I see if the diameters match up between the new and old shifter mounts just to be on the safe side, but I doubt I can find that info anywhere.

You cannot upgrade to 8-speed just by changing the cassette even if you use 8-speed shifters. The 7-speed freehub body on your current hub is too narrow for an 8-speed cassette. You would have to change it for an 8/9-speed freehub body (they are the same) and have the wheel respaced and redished.

You're right. I forgot about this. An 8-speed cassette won't work on a 7-speed freehub body but a modified 9-speed cassette will. I was thinking of the trick of using a 9-speed cassette with one cog removed. You will need to disassemble (they're held together by little rivets which can be easily lopped off) 8 of the 9 sprockets (pick and choose which you want to use) from the new cassette and stack them on the old 7-speed freehub body using the 9-speed spacers.

http://www.bikemannetwork.com/biking/p/COMPCASS9MTN/FW8421

Of course you'd also need to use a 9-speed chain.

http://www.bikemannetwork.com/biking/p/COMPCHBRSRAM/CH1084

Going all the way to 9-speed will increase the price of the shifter pods by 60% over 8-speed and is close to twice the price of sticking with 7-speed.

http://www.bikemannetwork.com/biking/p/COMPSHMTNSETSH1/LD7535

One more quick question regarding the 1993 shimano Altus A10 index shifters on my old mtb: I read some interesting posts regarding fixing an index shifter by removing the covers and spraying the internal parts with WD40 with the hope that this will loosen up whatever obstruction is causing the shifter to malfunction. I've tried that with the front shifter on this bike, even tried blasting the insides of it with air after coating in WD40, but no change. My question is how do you know if the shifter itself is broken, or if gunk or something else is preventing it from performing correctly?

^^^This is what I saying in post #5. Sorry I never elaborated. Try this:

1. Remove all the plastic that is remove-able.
2. You will see 2 pawls, one that makes the shifter pull the cable and one that releases it. Check whether the pawls completely engage the teeth.
3. Move the faulty pawl in and out to release the gunk that is holding it back. Use a pick or small screwdriver. Also clean the ratchet teeth.
4. Spray with degreaser.
5. Blow with air-compressor if you have one, or rinse with water.
6. Repeat 3-5 until it starts to consistently engage.
7. Lube with light oil, silicone or teflon.
8. Re-install

Just cleaning up my Cannondale M500, with the same gear set Altus A10.

Turns out as previously posted on this thread the problem was with the ratchet sticking.
Cleaned the insides with WD40, but it was still sticking.

The pawl is on the push selector and a load of old grease was solid and wasn't allow it to move freely, cleaned this all up with some white spirit and an old toothbrush, and I can now select all 3 gears on the front.

I know this thread is old, but having search on this problem and found this thread I thought I would share the solution.