Anyone adapted hydraulic brake levers (e.g. 105 or Ultegra) for use with rim brakes - e.g. using inline mini cylinders to drive rim brake?

Question

We all the know the frustration of newer equipment making older stuff obsolete. My big issue is that I have some terrific rim brake wheels and bike and so I'm loathed to switch to a new bike / disc for my summer riding. But I do want to use 12 speed Shimano stuff.

The Shimano Ultegra 12 speed do both a rim brake (R8100) and hydraulic brake (R8170) version, but only the hydraulic version is shifter wireless, the rim brake version is wired.

The lower priced Shimano 105 12 speed only do a hydraulic version (wireless shifters)

It is clear that Shimano's trajectory is di2, wireless shifters, 12 speed, hydraulic and if I do end up migrating to hydraulic at some point in the future, I don't want to 'throw' away a £1.2k investment, so I want to see if I can use future proof stuff with rim brakes.

Answer 1

I don't know that you can adapt the levers themselves. However, you can connect hydraulic levers to hydraulic rim brakes.

The issue would be finding someone to make good hydraulic rim brakes. There is little demand for this. Some do exist - SRAM had a set of hydraulic rim calipers for a while, and Magura made or makes some hydraulic rim brakes. But the limited demand means that this will be a niche item.

It's not impossible for niche items to persist in the market. Cane Creek makes the eeBrakes, which are (cable-actuated) ultralight rim brakes, and which are definitely a niche item. That said, hydraulic rim brakes would be expensive. If the manufacturer wanted to cover both mineral oil and DoT fluid options, and if they felt they needed to cover multiple mineral oils because Shimano and Campy don't quite use the same oil (I think), that would probably raise the price.