I was asked to show how I make a conversion for older bikes to use the newer STI, ERGO or
SRAM's double tap shifter systems. I figured I needed pictures so I made this page. Try it out and let me know if it
worked for you. Just hit the LINK.
Derailleur adjustment. When I have got a problem with the derailleurs I always start by just looking at it, all over, from a lot of different angles. Even if you are not sure of what you are looking at just look it over. Are the cables rusted? Are the derailleur bent or broken? Is the chain or cassette bent or broken? These are all things that are hard to see until you look at it from different angles. If all that looks good lets go get a repair stand. An extra word here on Shimano STI shifting systems they are very prone to not shifting well when it gets cold. If it works when you take it in side to work on it that might be your problem and time to oil the shifting pods with a lighter oil.
All derailleurs systems can be broken down into three parts. The shifters, the cables, and the derailleurs.
First thing to do is separate them. So now we need the repair stand to hold the bike up to let you do some things. You can shift the rear derailleur with your thumb to see if any problem shows up. Just push it all the way in and let it go all the way back down. If you hit the spokes or do not come all the way back down it is most likely a bent rear derailleur hanger or a damage derailleur. If it is a bent hanger let the shop do it, the tool you need is more then the average homeowner needs. If it is the derailleur time to shop for a new one most are not rebuildable. On the front derailleur just pull on the cable that runs exposed down the down tube or the top tube on a mountain bike and see how the derailleur behaves. It is so nice to see it up close when you are shifting and so much easier to see problems then from the bike saddle. If the cage is not lining up with the chainring that can be a problem that is easy to fix. Just loosen the bolt the holds the derailleur on to the bike frame and move it until it lines up with the chainrings on the crankset.
The second part is to check the cables. Undo the pinch bolt the holds the cable on the derailleur and pull the cable back and forth. It should be perfect no hang-ups at all. Remember the spring in side the derailleurs are very small and do not have a lot of pull in them so if you are at all in doubt replace the cables. The cables are the number one problem with derailleurs not working right so this is the big one.
The third thing to look at is the shifters. With out the cables pulling on them you still can feel the pull of the cable in you hand when you shift them. So shift them up and down and count the clicks. If it is the Shimano STI shifters you may have to spray a light oil in to the shifter pod to free up the little paws and springs in side them. Use an oil not a penetrating spray. Really flood them over some paper towels and keep trying to shift them up and down. If they do not come back it is time for new ones they are not rebuildable.
So now it is time to put it all back together. Remember to tell the store what size and type of shifters you have because the cables are not all the same. And if you are getting new cable housing take the old ones in and let the shop cut them to size the cutter for the new index cable housing is a little pricey. Also use an pick to open up the end of the cable housing to cut down on friction in the system.