Hopefully you join here having read:
I'm not really convinced that using a TriRig Omega X provides any aerodynamic or functional benefit over a dual-lever design from either SRAM or Shimano, but I wanted my brakes to match, so I got one for the rear.
Because of the design of the rear of the frame of the S5, Cervelo uses a mounting adapter for the rear brake. The brake is mounted to the adapter and the adapter is then installed onto the frame.
The Omega X is nicely packaged and contains everything you need to mount the brake to a variety of frames.
TriRig provides a large stack of a variety of spacers to maintain clearance. Due to the design of the Omega backing plate/cable stop in conjunction with the design of the S5 frame (size 51 in this case), I had to use all the spacers, plus a leftover from the front.
I didn't like this for a couple of reasons.
- It looks bad.
- Having the braking force applied at the end of such a long lever arm dramatically increases the stresses on the bolt and mounting point
From the picture above, I surmised that if I removed some of the (structurally unnecesasry?) material on the corner of the cable stop area, I could remove some of the spacers and improve the setup.
I'm sure this voids the warranty.
After some work on the bandsaw and a couple passes with a metal file, I arrived at above solution. A significant improvement, so I painted and installed.
The Force 1 derailleur is specifically designed for single front chain rings. It has a roller-bearing clutch that prevents chain bounce, which can throw the chain off the front ring. The downside is the weight; this piece is heavy. A SRAM Force 22 non-clutch, short-cage rear derailleur is only 178g. This one is 260g for a mid-cage. Mid-cage allows for up to 32-tooth rear gears, but I'll be running 28t. There is no short-cage option for the Force 1 derailleur.
I spent a long time getting the rear brake cable housing as short as possible, which still allowing full rotation of the handlebars. In pursuit of marginal aero gains, I made the cable too short on the Allez build, which made the rear brake engage when the handlebars were turned too far. It was never a problem while riding, but I was constantly annoyed by this while walking the bike around at stops.
On to Part 4 - where I have to totally re-do the bottom bracket (?!?!?!)