I have no trouble using the Magura brakes on the 24" or the 29". The Coker is set up with a Shimano V brake. The rim seems true. I did toe the pads in slightly a couple of days ago. I will have the chance to try it out tomorrow. It gets too dang dark so early now. Until Santa brings me a good helmet light I’m not riding hills after work. If it’s still a problem then maybe I’ll get the wheel checked to make sure it is really true.
Nice idea! Hope it works out well.
As for rim brakes on 36", the old Airfoil rims worked better than the newer Stealth ones, but if you sand the braking surface to be smoother you may find it works a little better. Mine works great in low gear. In high gear, it is a skill you have to learn. I am getting decent at it, but haven’t quite mastered it. It is quite exciting on bumpy dirt roads, fast, in high gear!
It would be pretty cool to have a disc I think.
—Nathan
I wonder how braking would be affected if you did this with a GUni in high gear. I guess it would be less powerfull in high gear but that could also be a good thing.
Disk brakes work really well on 36" wheels. They are really smooth and even when used with cheap cable calipers they out perform the very top of the range hydraulic rim brakes. When you fit a hydraulic disk brake the performance is staggering, it opens their use to a wider range of riders.
Roger
Why couldn’t you use a set of MTB ISIS cranks, then use the drive side spider to attach the disc? It might require some adaption, but the spline is already there…
Great idea!
So why doesn’t UDC carry the parts needed to do this? I see you’ve got a v-brake adapter on the UDC-UK site; how about adding cranks with a spider, and maybe some kind of bolt-on mount for the calipers? Or better yet, maybe the next generation of nightriders could have a disk brake option?
Hmmm, what a good idea. Of course I can not tell you if it will happen or not… or about the auto balance control or the twin jet pack or the optional barbacue set. If I did tell you I would have to kill you… or something like that.
Roger
Fair enough. But for what it’s worth, I think a disk brake would complement a twin jet pack quite nicely. 
. . . and I for one would definitely buy a nightrider with a disk brake if you make it.
Jet pack, of course! The perfect heat souse for making a couple slices of toast.
You keep mentioning the barbecue set but I think most of us would be happy with just a toast rack. No need to go overboard.
On the subject of crank mounted disk brake disks I have been thinking of getting a centerlock adaptor, drilling it out and threading it to thread onto my trial bike cranks that I use for MUni. That would definitely be the easiest way for me to put on a disk without major modifications.
We could adopt threaded cranks like trials bikes… The standard is already out there and we might get more cross-pollination of parts. You would just have to be careful not to apply your brake while riding backwards or they might unscrew!
Excellent that will save some development time. The barbecue set was causing us a few headaches. Toast rack it is then. 
Roger
regarding ISIS mountain cranks to disk… I’m on it’, like last week. the important part will be what kind of spacer is made between the mount and the caliper. So, there is a market for this, even if you have to find a welder to mount the caliper to your frames?
unless, and even, if frames with disk mounts and disk ready hubs eventually become available… (like disk brakes evolved on everything else) will there still be a market for crank mounted disks to retrofit existing unicycles?
If you had to buy a new wheel and frame to upgrade to disk, would the option of a cheaper “upgrade” still be relevant for some time -especially if you already have cranks and the brakes from an old mountainbike?
I mean, you can’t readily get dual hole square taper cranks, and to get that and disks in one upgrade… smellin what I’m steppin in? Keep ur eyes open, They’re comin! Who wants them?