08-26-2020, 08:31 PM
Hi, I am new to working on bicycle gears and am hoping to get some help determining if my new shifter has failed or if I just need to make some more adjustments.
On the left side shifter, I am able to shift easily from 1st to 2nd, but when I tried to get it to go to 3rd, the chain would go up, but the shifter wouldn't lock into place. It would be great thumb exercise, but I prefer to fix it. I took the cover off and saw that the cam would rotate, but would stop just shy of going far enough to allow the lock to click in. I loosened the cable all the way and then tried it and the locking mechanism would lock with no problem. As soon as there is any tension on the cable to get the chain to shift into 3rd gear, the cam won't travel far enough to allow the locking mechanism to lock the cam in place.
I have already read about the problems with older shifters needing to have the old grease removed and new grease put in, but I believe this is a different problem.
I'd appreciate any help! Please let me know if you need pictures.
Many thanks,
Chris
It sounds like your "H" limit screw needs to come out further
There are two kinds of people in the world, "Those who help themselves to people, and those who help people!"
I tried adjusting the limit screws and unfortunately did not work. I believe the problem is in the shifter. After observing more closely with the cover off, I noticed that there appears to be another cam below the first one that was harder to see. When I slowly press the trigger, the little ratchet immediately catches the cam when shifting from 1st to 2nd. However, when shifting from 2nd to 3rd, the ratchet is not immediately catching the cam when I push on the lever. I believe this is why the shifter is not turning far enough for the locking ratchet to catch the upper cam. Are there are any other adjustments in the shifter itself aside from the wire tensioner knob?
At this point I would ask what the model of shifter you have, how many speeds..i.e..3x7, 3x8..etc
There are two kinds of people in the world, "Those who help themselves to people, and those who help people!"
Thanks, I have a 3x7 ST EF51. I just received the replacement shifter today. I understand that after I set the limit screws, I need to ensure proper tension, any thing else I should check when installing the new one? Even with my old grip shifters, I had to really twist the shifters to get it to the largest cog.
As I was installing the new shifter, I looked more closely at everything. It appears that my cage is bent so that the inner part of the cage is bowed away from the outer cage, which appears to be straight. Perhaps this is why I have to move the shifting mechanism so far when shifting the front into third gear. I am going to try to straighten the cage. I'll post again when I am able to do this. Maybe I will have to buy a new derailleur.
Problem solved! I used vice grips to straighten out the derailleur cage and everything works great now! Then found my rear derailleur cage was also bowed outward, though it didn't affect the mechanics of it. Bent that mostly back into shape also. I love my new shifters. Much better than my old twist grips. Also added on some nice handle bar grips to make the bike like new, almost...
However, now I see that there is wobble in my crank shaft, which I think means I need new bearings. Maybe I'll do that in a few months.
You could also have too much tension on the line of the front derailleur that the shifter can't brunt the force of the line and the mech. This was a noob mistake I made many years ago. The shifter can't pull the line into the large chainring and will snap if you force it.
To troubleshoot this:
Shift into the smallest ring (3rd gear) undo the cable. Dial the barrel adjuster on the shifter all the way in (clockwise). Attach the cable lightly with just a subtly tug to remove the most basic slack. Begin to dial out of the adjuster and attempt to shift until it begins to shift smoothly.
Check the low limit screw to make sure it's not obstructing your shift. Screw it out significantly until it allows a full shift. Then, once shifted into the large chainring, peek into the mech and screw it in until it puts a light pressure on the hammer.
If this doesn't fix your problem the mech or shifter must be broken in a more dynamic way (gears, pivots, springs).
Problems with new 3x7 trigger shifter (ST EF51) on 3 side [Solved]
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