Hey everyone!
I’m an adaptive cyclist with a bit of a brake issue. I have a short right arm with only two fingers, so I can’t shift or brake my bike with that arm. For the past couple of decades, I’ve been using a Problem Solvers splitter for my cable-actuated brakes. For shifting, I used the right lever with a bar end shifter, and it all worked great!
A few years ago, I bought a mountain bike, and my mechanic McGyvered a hydraulic splitter from a recumbent bike to work with my SRAM Level Ultimate hydraulic brakes. We could increase the pressure in the front caliper while bleeding and lock it in. It has worked great!
However, I’m having trouble with my road/gravel bikes and SRAM Red and Force brakes.
When I set up a new bike a few years ago with hydraulic brakes, I used a TRP Auriga Twin Hose Splitter to split the hydraulic line. This allowed the right lever to pull both front and back brake calipers, just like my Problems Solvers did for my cable-actuated brakes and what worked on my mountain bike. But here’s the catch: it significantly reduced my stopping power when I used the TRP splitter (and tested others) on the hydraulic brakes. In short, it took an unnecessarily long distance to stop. It’s tough to be in a group ride without brake power. So, I went back to cable-actuated brakes using an older SRAM RED lever that takes the cable and also lets me use the electronic shifting. The brake calipers I’m using are Pauls Components Klampers (all the pictures are below).
I called SRAM, and they told me that my road and mountain bike brakes systems have the “same fluid ratio.” They suggested that I try to reduce the “dead band.”
Long story short…it looks like I need to get creative and use tree syringes to massage the bleed so I can adjust the pistons to position closer to the rotor than the SRAM factory spec.
And yes, I can stay with the cable actuated. I would just prefer to used hydraulic and clean up the bike a bit.
Now that I’ve written this novel, I’m wondering if anyone has done anything similar or has any thoughts on things I should try? Any help would be greatly appreciated!
by LordStarkinBend
4 Comments
Typo. Adaptive LEFT arm. 🙂
To advance the pads a bit just pump the lever once or twice with the wheel out. Or…
Swap out your lever to one with a larger master cylinder. Or callipers to ones with smaller/less pistons. The brand of your callipers and levers does not need to match if it works in your special application, just make sure it uses dot/mineral.
Have you tuned your front/rear mechanically in any way? Given the 50/50 pressure your splitter will give, a large front rotor and small rear would help bias. Combine that with mismatched callipers and some pad changes you could really get this dialled in.
Hope offer a 2 piston (RX2) and 4 piston (RX4+) that work with SRAM. Not sure if that would help but thought I’d mention it as they’ve got an adaptive MTB brakeset (Tech 3 Duo) so might be a bit more clued up to circumstances like yours.
I guess the intermediate option is to try cable actuated hydraulic calipers and see if that works for you. As far as getting the hydraulics working, you can try doing a overbleed by using an undersized spacer or simply by leaving the pads and rotor in place when bleeding at the lever. I’m also wondering if there are other things that can be done to increase or redistribute pressure, for example by using one hose with smaller inner diameter after the split. I’m sure there’s someone out there with a good understanding of hydraulics who could give a better suggestion, maybe you can get past SRAM regular CS and get the email of an engineer there?