Yesterday, I put up the post about the Actos Machine tandem build focused more on the drivetrain. Besides the R601/R603 cranks, it got new Ultegra 6700 shifters and derailleurs and an XT 11-32 cassette. The shifters were installed on a set of Ritchey WCS carbon bars. The Ritchey WCS stem was fit to a quill stem adapter (1" threaded fork). The rear bars are Fyxation time-trial style bars in 25.4 to fit the titanium adjustable stoker stem. A SRAM red aero bar brake lever operates the cantilever drag brake. The red color lever is a nice touch/match to the red King hubs and red vintage Salsa quick releases for wheels and seats.
Part 2 will mainly deal with the rear chainstay mounted WTB Speedmaster roller-cam brake. During my work on the bike, a friend who used to work at the old Point Reyes Bikes, where the bike was originally sold and built, recalled having had plenty of issues with the rear brake when building it originally. The one thing about the rear brake that stood out to me was that there was minimal clearance between the cam and the bb shell. There was no cable guide. The shift cable, originally, ran across the bb shell without a guide (there was a large thin washer between the drive side fixed cup and the bb shell. I assumed this to be to keep the guide-less shift cable from migrating off the bb shell to the right. Maybe this was okay with the previous drivetrain, but this new 10-speed set-up would need to be a bit more precise.
I decided the rear shift cable needed a guide to keep the cable from moving across the shell. I modified a Shimano guide by cutting off the front derailleur cable guide and thinning out the guide to make it as low-profile as possible and installed it as far to the right as it would fit to allow space for the cam.
To address the issue of the cam hitting the bb shell when the brake was applied, I dug back into a bag of tricks I learned long ago. Dug deep. WTB roller cams use a stainless bushing that fits on the brake post. Then the arm with the pressed-in bronze bushing slips over the bushing and rotates around the bushing. The arms also have a Grease Guard™system where grease can be injected into the side of the arm and then runs around a groove on the stainless bushing, thereby greasing the pivot and making it rotate smoothly.
Years ago, I recall needing to modify another WTB roller-cam by pressing the arm onto the bronze bushing in a different location. When moving the arm on the bushing, you lose the ability to push fresh grease between the bushing and stainless pivot - unless you make a new groove. Making a new groove requires relocating the bronze bushing first, redrilling the bronze bushing, and making a new groove in the stainless pivot. Easy. But slightly time consuming.
The brake is in the stock position. The hole in the side of the arm is where grease is injected.
The arm relocated on the bronze bushing - gaining critical clearance for the cam to pull.
Yeah, that's going to work nicely.
(What's playing: Gang of 4 I Fled)