ColinJ
Puzzle game procrastinator!
- Location
- Todmorden - Yorks/Lancs border
I fitted a triple to my Cannondale CAAD5 last year. I was surprised (but very pleased!) to be able to get it to work with the old ergopower shifters and derailleurs.
I have done about 4,000 miles with that setup and it has performed well, but eventually I wore out the chain and cassette, which I replaced a few days ago and have discussed above.
Yesterday's ride took me up a very steep climb for which I needed my little chainring but I discovered at the foot of the climb that I could not get the chain to shift down by operating the shifter. The chain was scraping on the inside of the derailleur cage but it would not shift. I got off the bike and adjusted the lower gear endstop but it made no difference so I pushed the chain down by hand and then it worked fine (apart from a lot of noises which will be investigated over the next few days).
The same thing happened on another couple of steep climbs so I resolved to sort the problem out back at home.
I just spent 20 minutes trying to work out what was going on and decided that it worked with the old worn chain because that was more flexible sideways. The chain was bent far enough by the mech to slip past the next tooth coming up and trying to hook it. The new chain is much more rigid and so does not deflect enough to be pushed off the middle ring.
So ... Why wouldn't the mech move over further and do its business? It wasn't an endstop problem because the mech was not even touching the endstop. I could take the screw adjuster out and it made no difference. It wasn't excess cable tension, because I disconnected the cable and still had the same problem ...
I thought about a bodge fix involving either bending the outer plate of the mech or turning it so it was no longer parallel to the chain but both were bodges too far!
Then I had a closer look and spotted what the problem was! Here's a photo illustrating it. Look at where the end of the screwdriver is pointing inside the red ring. There is a small metal tab against which the derailleur spring acts. That tab was jamming against the seat tube when the mech was swung over to shift to the little ring. It wasn't surprising, because that mech was only designed to work with double chainrings and the endstop would normally prevent it moving that far.
Anyway, once I realised what was going on, I took the mech off and filed about 0.5 mm off the tab and that gave the mech enough extra movement to work reliably every time and I think the shifting will improve as the chain loosens up.
Now I need to get rid of the offending noises. They could be due to worn rings and/or bottom bracket. I'll take the chainset off and see how smoothly the BB turns. I think the problem is probably due to worn rings. If so, I'll check to see whether they can be turned or filed, and if not I will replace them.
This is my best bike and I just want to sort out the remaining little problems to get it working perfectly again because I have big plans for it next year!
I have done about 4,000 miles with that setup and it has performed well, but eventually I wore out the chain and cassette, which I replaced a few days ago and have discussed above.
Yesterday's ride took me up a very steep climb for which I needed my little chainring but I discovered at the foot of the climb that I could not get the chain to shift down by operating the shifter. The chain was scraping on the inside of the derailleur cage but it would not shift. I got off the bike and adjusted the lower gear endstop but it made no difference so I pushed the chain down by hand and then it worked fine (apart from a lot of noises which will be investigated over the next few days).
The same thing happened on another couple of steep climbs so I resolved to sort the problem out back at home.
I just spent 20 minutes trying to work out what was going on and decided that it worked with the old worn chain because that was more flexible sideways. The chain was bent far enough by the mech to slip past the next tooth coming up and trying to hook it. The new chain is much more rigid and so does not deflect enough to be pushed off the middle ring.
So ... Why wouldn't the mech move over further and do its business? It wasn't an endstop problem because the mech was not even touching the endstop. I could take the screw adjuster out and it made no difference. It wasn't excess cable tension, because I disconnected the cable and still had the same problem ...
I thought about a bodge fix involving either bending the outer plate of the mech or turning it so it was no longer parallel to the chain but both were bodges too far!
Then I had a closer look and spotted what the problem was! Here's a photo illustrating it. Look at where the end of the screwdriver is pointing inside the red ring. There is a small metal tab against which the derailleur spring acts. That tab was jamming against the seat tube when the mech was swung over to shift to the little ring. It wasn't surprising, because that mech was only designed to work with double chainrings and the endstop would normally prevent it moving that far.
Anyway, once I realised what was going on, I took the mech off and filed about 0.5 mm off the tab and that gave the mech enough extra movement to work reliably every time and I think the shifting will improve as the chain loosens up.
Now I need to get rid of the offending noises. They could be due to worn rings and/or bottom bracket. I'll take the chainset off and see how smoothly the BB turns. I think the problem is probably due to worn rings. If so, I'll check to see whether they can be turned or filed, and if not I will replace them.
This is my best bike and I just want to sort out the remaining little problems to get it working perfectly again because I have big plans for it next year!
so I've cleaned and lubricated it and it'll be good as a spare.
It's my first road bike 
