Shift Linkage

The shift linkage/assembly has always been a pain in the ass.  The way JG set up the rig it was quite literally built for him, and nobody else.  By sheer luck Sarah was able to get in the rig and mostly use the shifter with nothing but minor adjustment.  But if we wanted faster/smoother shifts it was going to have to be fine tuned and all the slop taken out of things. 

The way the current setup works your foot goes into a toebox that hangs from a rather loose heim joint.  The toebox is a bit wide so there is too much free play between your boot and the upper/lower bar of the toebox.  From the toebox you have a non-adjustable pushrod with heim joints on either end that connects to a 90 degree bellcrank.  From the bellcrank we go up to the stock shifter pushrod and to the stock shifter bellcrank on the end of the shift shaft. 

The first problem I noticed was that the stock bellcrank on the shift shaft was not in the ideal position for optimial up/down leverage on the shift shaft.  It was about four cogs too high on the spline, or about 45 degrees.  This put the direction of force from the stock pushrod too far on the inside of the bellcranks direction of travel.  This was easily fixed by just dropping the bellcrank down till it made a 90 degree angle with the stock pushrod.

The second problem was the non-adjustable pushrod between the toebox shifter and the lower bellcrank.  This was quickly solved by taking the stock part to Orchard Supply, buying some Allthread, a couple heim joints, and jam nuts.  I threaded one heim joint all the way onto the end of the Allthread and set the stock linkage next to it.  I made an index mark 1.5 inches shorter than the stock pushrod, and took my dremel to the Allthread.  Once I had it cleaned up and quickly test assembled on the CSR with all new fastners it was obvious the new pushrod would allow more than enough adjustability.  I could drop it back enough for my foot to knee length now if I wanted to.

Lastly was taking all the slack out of the top heim joint that the toebox shifter hangs from.  I simply replaced all the old fastners and furry washers with new hardware and some nice thick powdercoated washers I had in my parts bin.  This got rid of nearly all the sloppy feel in the shifter while leaving just enough to allow pivoting and lateral movement of your foot without bumping the bike out of gear.

The original non-adjustable pushrod


The adjustable replacement


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