Strut attempt #2
0.5mm wall mild steel tubing
25g 
My solution to the vibrating brake was to switch from sintered metal pads to rosin organic pads. Not perfect but I would consider it a 80% fix, and it particularly helped on the slightly softer Mountain Uni disks. I haven’t tried a brace but imagine it would be a much better especially if if set up like mowcius sandwiched between mount and adaptor.
One thing I recently found out is that you can’t use a 160mm disk with the Nimbus d’Brake mount, but it works just fine with a UCM brake mount (at least with a 160R/180F adaptor). This is slightly ironic as the UCM was specifically designed designed to be paired with their 180mm disk.
You can’t? I thought you just needed to use a 160mm front adaptor?
I used a 160mm rotor with a dBrake for a long time, it works fine.
BTW, here is my final strut design as of a few months ago 
I was getting a unicycle prepped for a trip, Shaved down a d’Brake to use it with a Schlumpf and KH cranks. I was originally going to use a 180mm disk like I usually do but both my spares seemed to have disappeared. I “borrowed” the 160mm disk from my bike and when I tried using the 160R/180F adaptor flipped there were clearance issues at the bottom. I could not find my 160F adaptor, It was probably with the disks and a few more odds and ends I seem to be missing. It fit fine on the UCM.
I had thought that I had run a 160mm disk before so was surprised. You are probably right that I just needed the 160F adaptor.
Between the UCM, the d’Brake, and the custom Triton frame I had I don’t necessarily remember all the combinations I have tried.
Mountain uni?
I find interesting this thread…
[OT]
What’s mountain uni site to buy?
Someone spoke about square cranks with disc brake… where I can buy one?!? Does exist Sinz 125mm square-cotterless crank which could fit a disc brake? Where to buy in Europe?[\OT]
Mountain Uni doesn’t have an active website anymore. there are some old pages here:
I believe Jeff, who runs it, may have some parts (UCM, Cranks, Discs) still available. I will PM you his email.
This may present a challenge because a square taper spindle doesn’t have a hard stop for the crank. In other words each time you remove and replace the crank it may end up in a different lateral position.
I know square taper disc brakes have been done in the past, but the lack of stop alone would sway me away from using one over an ISIS setup.
Thank you!
Thank you all for your precious help!
Thanks for the help. Learned lots just by reading here.
Due to strong vibrations (unicycle turned in to a giant vibrator) on braking I had to do something to enforce the d’brake, so thanks for the tips in this thread. I used patentband which was what I had lying around. It’s not ideal because it is soft, but with 3 lairs and bolts to hold them together it worked well. When I fitted the d’brake to my KH36, I had to use 3 washers between the brake and the D’brake to get the brake centered over the rotor. I think this may have increased the vibrations. The patentband was exactly the same size as the washers, so I could just replace the washers with the patentband. I went for a 23 miles ride yesterday, and the braking was very smooth on the steepest decents.
A few months ago I bought a d’brake for my KH36, but the bolts were not flush with the d’brake. The one on the bottom was too close to the spokes because it was sticking out. I replaced it with and older version of the d’brake that I had on an Oracle 24, which is the one in the photos. Vibrations was never an issue with any of my Oracles (24/26).
I had similar issues with bolt head sizes and the d-brake - I had to dig around in my parts box to find some that were just small enough to fit in.
Just a quick update on my strut - I’m now on version #4 but this one’s been holding up well for a while so I’ve painted it to match 