Stem Shifter Tweaking

Hello reader(s),


Well, I bought cable housings for my vintage Giant Quasar bike recently.

The other night I had a crazy idea to make some modifications to the stock stem shifters. I like the simplicity and that the shifter controlling the rear derailluer indexes. However, I did not like their placement, especially when riding.

So that started me off into an adventure of disassembling, reassembing and relocating my stem shifters.


The first thing you need to know when working on these parts is that they are simple, but still a little tricky. The friction shifter, used for the front deralluer is comprised of a few shims and a wing screw. Pay attention to how each shim acts as a baring for the shifter and you won't have any problems.

The indexing side, on the other hand, is a bit more complex. There are still shims but they have a bit more order to them. 

Below is an exploded view of the stem shifters. The top one is the indexing shifter. The bottom is the friction shifter. Each is arranged in the order it came apart.  Note that ball barings are missing from the upper exploded view. There will be more on that later. When I took apart my indexing stem shifter it was late. I had a hair brained manic moment and went at it. It seems, many times, my ideas come to me that way. As usual in these momemts, something went wrong. Honestly it was a pretty minor SNAFU and I almost missed it. As I removed a snap ring that held the shifter assembly together I two tiny ball barings fell to the ground, deep in my basement's shag carpet. Luckily I found new ones at my local Sears hardware store. They were in the odd hardware section and measure 3/32'' in diameter. For reference to just how small these ball barings are the next picture is them next to a small screw used to fasten the shifters to the bike's stem. The smaller one's measured 1/16'' and were too small. The 3/32'' gave me the positive indexing feeling I had before I lost the old ones. Reassembly is a bit tricky since it involves very small parts, but with method there is minimal madness!

I basically assmebled the two notched plates on the small hub which the shifter rotates on. Then I added the ball barings. I put them on together against the small plate which gives the shifter its indexing. Here you can see the bare bracket and shaft. Notice the two small pegs that stick up. They locate a plate with little divits which gives the shifter its indexing. Here is the plate on the shifter. Notice the divits where the ball barings seat. This is how the ball barings sit on in the shifter mech. I ended up assembling them backwards of this photo once the shifter was on the bike. So first came the shim, then the black plate, then the ball barings then the bottom plate. Note there are divits on the bottom plate that line up with the ball barings. Finally here is the inside of the shifter handle with the shim/ baring inside.Notice the notches. It will only fit on the bracket one way making installation easy.

 Anyway once I verified that was the problem and fixed it, it was time to relocate the shifter.

For my bike THIS WAS NOT A BOLT ON AFFAIR. I just want to emphasize that so you my fair reader do not fool your self in a manic late night move inspired by an off hand thought. Honesty, in those cases, I'd say go for it. But, you've been warned.
The problem was my handlebar stem has two different shapes going from the horizontal portion to the veritical portion. The vertical portion, which goes down into the fork, was perfectly round. The horizontal portion, leading to the handle bars, was oval shaped. This presented a challenge as the shaft to which the shifters attach would not make it through the bracket that attaches the stem shifters to the stem. It got high-centered on the horizontal, oval shaped stem.
So I had to do some reshaping of the bracket. I also ground down the shaft. That's what it looked like after I ground it down with a carbide burr. This gave me the clearance needed to fit the shifter. Finally once I had it all fit up and the shifters were woking properly I attached some cables, mounted it and got it mostly adjusted. Of couse it still needs a bit of fine tuning. I have to say new cables and the relocated shifters alone really make the bike smoother and easier to work. Cheers and good luck! Let me know if you have any questions and I will give more detail.