I have a shifting problem on a bike that has a crank with a triple set of chainrings. The bike is a tandem. I have to put a great deal of effort to get it to shift into the big ring. Where should I start? Is there a simple adjustment I should look at first or should just jump right to replacing cables and housing?
Vitals:
* STI shifters
* 2004 Shimano Tiagra
* triple
* tandem
* probably same cables/housing from 2004.
* bike has 4000 miles on it, maybe more
First off, of course, lubricate the cables and assure that the derailers are properly adjusted.
After that, make sure you're not cross-chaining too much when shifting up -- you should have your rear near the outer cog before up-shifting the front, so that the angle of the chain isn't fighting you. Also, understand that you must let up a hair on the cranks when up-shifting the front -- don't do it under full load.
But if not that then likely the rings are worn out. Even if the chain and rings gauge out OK (did you check them??) the ramps on the side of the big ring may be worn to the point that they're no longer effective.
This is not uncommon with the old Shimano components. I had the same front derailleur and 105 STI 9-speed shifters and I had to really crank it to go into the larger cogs. The bike shop replaced the cabling (there wasn't much housing) and that really didn't help all that much, though I wish it did. The problem sort of fixed itself when I purchased a new bike with modern components. 2009 or later shimano 105 (shifters and derailleurs) are much, much easier to shift up through the cogs. Just push the button and it takes care of the rest. No having to push on it to get it to the next cog.
I am sorry I wish there was more I could recommend, but in my experience, there is not much you can do with that setup...
With my older Shimano setup I found that as it aged I had to adjust the limit screws on the front derailleur to allow it to travel past the correct position because it would then settle back a couple of millimetres - probably most of the cause was old cables, but some was definitely just old/worn components in the derailleur itself allowing flex.
As @bwalk2895 mentioned, it is an age thing - you can hold it off by tweaking (and in fact mine was much older and was still usable when I finally retired it for a new bike) but changing cables is relatively simple and should help a bit.
I know this is an old post but it comes up top in search and so might help others.
I had this problem with SRAM Rival, stiff front derailleur and a loud clunk when shifting to the small ring. I found that it was caused by a misrouting of the cable around the anchor bolt such that excessive force was required to overcome the poor leverage.
After fiddling with it for ages I moved the cable outside of the cable pinch bolt clamp to give greater leverage. I am convinced that it is a poor design of the front derailleur lever which isn't long enough.
I could solve this problem by replacing the front derailleur with one that satisfied the following conditions.
The spring is weaker than the current one.
When the cage is between the 2nd gear ring and the third gear ring, the arm to which the cable is attached becomes almost horizontal. This condition maximizes the force exerted to make a shift from the 2nd gear ring to the third gear ring.
The derailleur selected must be able to cover all the gear rings.
I had this issue after upgrading my crank, and the chainline was out a couple mm further to the right. I didn't want to get a new crank axle so in my workshop I custom cut some sheetmetal then folded it over in my vise for about 2 or 2.5mm thickness. Then I cut, filed and bent it to match the left inside of my derailleur cage. I used JBWeld to attach it to the left side of the cage. I can now shift much more easily onto my big ring. To avoid chain rub from the right side of my derailleur cage while on the big ring, I put a 3/4" piece of wood over my crank axle then with my biggest flathead screwdriver pried outward on the outer cage wall until there was no rub while in the big ring. While readjusting my cable, with better lighting I noticed that the screw that limited how far my derailleur could swing outward, was actually closest to the frame, not on the outside. This was also part of the problem but I still needed to address the chainline issue with my diy fix.
It is an inexpensive derailleur (Shimano Tourney). This derailleur seems to have a very strong spring. I wish they had engineered it with a spring with half the strength, that would make the front shifting as effortless as the rear, and would put much less tension on the cable and the guide the housing rests on going into the frame internal routing.
Park tool's site breaks down how to adjust the front derailer pretty well. http://www.parktool.com/blog/repair-help/front-derailleur-adjustments
Check the high limit screw first. If that doesn't do it, you probably want to play around with the indexing adjustment (possibly needs some tension due to cable stretch over time). It's not going to hurt if you lube the existing cables as well.
