Rohloff Shifter Cable Routing Problems on My Bob Jackson Touring Bike
I originally setup my Bob Jackson Touring Bike with the shifter cables routed in a way that probably caused premature failure of the cable housing and cables. This occurred at a very inconvenient time during a cross country bike tour during a cross country bike tour. I am documenting this problem here with the hope of preventing someone else from making the same mistake.
When I ordered my custom frame from Bob Jackson Cycles, I asked them to equip it with cable guides for a Rohloff Speedhub. I did not specify where to place the cable guides. When I originally outfitted the frame with Rohloff cable housings (shown in yellow), I routed them through the cable guides (shown in red) with the shifter mounted low on the stem.
This resulted in too sharp of an angle as the housing turned into the most forward guide. Eventually, the housing fractured at this point. Using these cable housing guides might work fine for a bicycle with a flat bar where the shifter is positioned farther above and forward of the first guide as show below in green.
When the shifter cable housing completely failed stranding me in rural Florida, I re-routed them as shown below with the cable housings highlighted in blue. I moved the shifter higher up on the stem and did not run the cable housing through the most forward cable housing guide. This resulted in gentler bends of the housings.
The pictures below illustrate the same issue with the aft cable housing routing. My original bad routing is shown in yellow. The housing passed through a guide on the seat stay. Both the 1 and 14 cable housings fractured at this point. If one were routing the housing directly to a Rohloff external shifting mechanism rather than to the brake boss, then using the cable guide on the seat stay might not cause problems as shown in green.
When I revised the cable housing routing (shown in blue below), I did not run the housing through the guide on the seat stay. This again resulted in less abrupt angulation of the housing.