I would have to measure with callipers but it loos like the Koxx bearing holders have the bolt holes look to be 50mm apart centre to centre. Quite a bit closer than KH or Nimbus.
maybe we’ll get that done on the next batch, I think the narrowist ours will fit at the moment is 52mm. Thanks for doing that dude!
Kris Holm made a good observation…
I used a grinder with a cutoff wheel to shear the “nub” off of a shimano brake lever and when I attached the KH spooner it fit perfectly! (some levers are fat enough to crack the spooner upon installation.)
http://www.planet-x-bikes.co.uk/imgs/products/440x380_constWH/BCSHXTM765_P1.jpg
(I like to check cambriabike.com for short money brakes that were taken off older model bicycles!)
Here’s a thread on custom spooners…
compatability, adapters, and the Uni-Caliper Mount…
The frame tabs that we are making and those that are on frames like Triton, accept only 160mm adapters or “stand-off”, even for our 180mm rotors.
the new Uni-caliper Mount that replaces the bearing cap and facilitates attachment of a caliper to bolt up, will allow the installation of 160-203mm adapters. The difference is, that if you wish to use our 180mm system, you have to get a 180mm adapter for the caliper that you use, or buy a brake that comes with a 180mm rotor.
Eventually, we intend to have a system that will support different sized rotors and you will be able to use 185mm avid system for instance. However, as it stands, any frame mounted tabs on Triton or using our tab mounts will just use the most common 160mm adapters.
I hope this won’t be too confusing.
weld on tab = 160mm iso adapter
bolt-on “Uni-Caliper Mount” = 180mm iso adapter
getting a “post mount” with iso adapter is the most adjustable.
This way, if you wish to use an internal 160-203mm rotor on the left side on a UDC impulse hub (not tested) our Universal caliper mount may also work in that context (theoretically) to retrofit your nimbus uni.
ooooooh…
Sweeeet!
Wow! Unicycle Porn!
I guess the internet really is for porn. 
Scott
yeah, I’m a sucker for Uni Porn…
Any word on hoe the Clark’s caliper works on a uni? I may have to get one.
Clark Skeletal for Disc MUni
Nothing Negative to say about any of the brakes we’ve tested. However I will say that the lever position on the Clark Skeletal is ideal. It is very precise, and the small throw screw in front of handle gives between 5-7cm handle-to-spooner variable. Obviously aesthetically appealing brake too. 
Close to getting a deal to get calipers and handles added to the Mountainuni packages. It won’t be a required buy, but if customer’s wanted, it can be added to an overall kit purchase. Lots of choices, so I don’t want to make anyone’s decision for them. Especially when colors are involved.
I got my baby back this morning… still it’s waiting for T-bar to attach the lever, so probably first real test in two days (I hope).
The caliper has been filed to make IS mount fit easily with the rotor bolts.
I am loving your pedals
If you do drill and bob Sinz cranks, it would be cooler to just hack up some 175’s, since anything under 155 is rare and would be a shame to cut down. We are working on a solution for crank sizes in ISIS… and multiple pedal positions.
100/125/150 or 110/130/150 for pedal positions?
while the website is under construction…
This link is for ordering product while we’re working on the site
purchasing notes:
We have not run into a hydraulic brake that didn’t work with the system -yet. I know that virtually any mechanical disc brake is too wide to work with this system.
as far as the cranks, we have tried other cranks and found that the rotor placement tends to run too close to the frame, the “dish” of the spider on the sinz is very shallow and keeps the chain ring bolts and rotor far enough away from most frames with an 8mm crank stop (spacer). You may certainly try other brands of cranks and post the compatibility on the thread, but the Sinz works and that is what we recommend.
So, please try other cranks, but if you are going to buy them, I’d stick with Sinz. We have ruled out AC and redline bmx cranks so far.
Coker Cycle Co…
The Coker Cycle Company is content with the current v-brake system on their unicycles and will not seek to feature MountainUni.com disc brakes on their unicycles or as an option in the future.
We sent them a set and I don’t believe they even tried it because they are sending the mount tab back as well. They are conservative to say the least.
This does not mean that MountainUni will not be availing an aftermarket system consistent with their product in the future. We will be prototyping a Coker specific 40mm/threaded Uni-Caliper Mount, and if there is any demand, we will offer it in the future.
To those ends, are there any square taper Schlumpf hub users that ride Coker frames? Is Coker compatible with Schlumpf?
Nice color Vookash! (it matches the chain ring bolts perfectly too!) and thank you for the heads up on filing the brake with dedicated ISO mount, I think we’ll recommend post style brakes with ISO adapter in the future. Nice work, it looks awesome!
Measured the bearing mounts on my koxx 20" with callipers and the bolt holes were exactly 50mm centre to centre.
For the coker/square taper unicycles could you just put half a bearing shim in the holder and call it good?
we could, but if we have a sclumpf compatible 42mm bearing cap with the inside lip no taller than 2mm and we shim it, then there is only 1mm of material holding in the bearing. The other issue is that the Coker bearing caps are threaded. I think it’s cheesey to just put in longer bolts and nut them under the bearing cap and shim it! So, we’re making a proto for 40mm that will be threaded specific to Coker. Also, wondering if we should bother making it Schlumpf compatible, Coker may not be.