Mountainuni Disc Brakes Have Arrived!

That’s much better :smiley:

Now there shouldn’t be any issues with clearance with any hub/spoke combination. :slight_smile:

OK - I rcvd my brake today - the Gusset model.

Now here’s a problem I wasn’t anticipating…

The little tab sticking off the brake pad catches on the rotor nut-head. Do I need to clip the little tab shorter?

I attached a pic so you can see what I’m talking about.

oh yeah, I have done that a few times! sorry for not mentioning it… you should only have to do that on the outside. a dremel is easier to get at it than diagonal cutters, without taking anything apart. the brake looks fantastic! Once you’ve clipped the tab shorter, do you still have time for a quick spin or daylight enough for a picture of the whole Uni with the disc? I get so excited every time!:slight_smile:


you’re probably riding it right now! anyway, go one page back one page and see the gusset brake on Jeff’s KH, you’ll see that I cut down the brake pad tab on that one!


Dude, that looks like a fast wheel! did you use a 36er frame -or does the 32 fit the 29er?

Can you please give us a picture of the brake on the inside of the frame, and measure how much room there is between the disk and the spokes? I’m curious about whether the mechanical brake caliper discussed a few pages back will fit with a Schlumpf.

Jeff Putnam on a KH frame with UCM mounted MountainUni disc brake!

OK, I clipped off the brake-pad-tab, attached the brake to the adapter and actually rode the first Mountainuni disc-brake equipped KH/Schlumpf unicycle in the world!

Set-up particulars:
I moved the disc as far inward (left) as possible, with all 4 washers between the spider and rotor, because the brake was all the way to the right, and still seemed to be rubbing on the outside of the rotor. This leaves a VERY small clearance between rotor and frame, like a mm. So I might go back out (right) one mm (with 3 washers between rotor and spider, and one outside the spider).

When I spin the wheel, it feels like it’s slowing down just a bit from brake-rub. Is there a way to alleviate this? Is it just a question of centering the brake better on the rotor by loosening and re-tightening the
brake/adapter bolts?

Also, what’s the deal with hydraulic fluid and maintenance and all that? I mean I didn’t put any liquid into any part of it. Does it come all set to go, and then you only add and/or bleed the thing later or when necessary?

So I rode the thing briefly up and down the street (I had to go pick up the boy from Tae Kwon Do, so that’s all the time I had). But I did use the brake, and it is smooth as butter.

Tomorrow, a bigger ride with real hills.

I will do this tomorrow and get back to you.

There may be slight brake rub occasionally, but you won’t know riding it, and the pads should wear in to allow the rotor to pass uninhibited. the brake came pre-bled. Unless the brake lever is squeezed without the rotor in the caliper and a piston pops out, you unscrew stuff, or the hose becomes compromised you need not worry about bleeding air out of the system. You could loop the hose around the seat post and zip tie a tight service loop there to take up slack and add 2, 3/8" hose clips to the maggie bosses via water bottle bolts to secure the hose to the frame leg so you don’t get the hose caught on anything. if you move the rotor further away from the frame and the outside pad in the caliper rubs, you can put a few washers between the caliper adapter and the UCM also. I figure that maybe the c-clip may make the 6mm spacer act like an 8mm spacer, and we use washers to correct for that. seems like you have it working nicely though!

My friends have some badass Triton Unis, but yours is truly sick! a 2 speed KH with disc brakes and KH handlebar! Are you as psyched as I am with your rig?

This setup was essentially born onto and shaped by this forum, from it’s compatibility with Schlumpf hubs down to the logo! There is no better insight or demand available anywhere like period. Thank you for trusting our efforts, trying and testing these products. What a wonderful experiment this has been and what cool product to finally develop! I foresee many more products to come! Thank you Steveyo for giving us a shot on your rig, I am happy to see it work, and hope it will continue to do so for as long as you ride dude.

Can MountainUni build my Schlumpf hub into a 36er?

I am putting together a Schlumpf 36er very soon. I am having Josh drop ship a KH36 frame, and spokes at Silva Cycles. Can I have a MountainUni kit drop shipped and installed there at Silva as well? I am hooked on the disc brake on my Impulse and it just seems a shame to have Silva build my wheel with KH 165 moments when what I really want is the Sinz and the UCM system. How are you guys at building wheels if I ordered the Schlumpf hub straight from Florian? I have authored a bit of a rambling post over in the “How to order a Schlumpf hub” thread (link below) and I would appreciate any insight that all the wonderful knowledgable people at MountainUni might provide. Thanks!

While the 07 KH29 frame I have has massive crown height for any 29" tire that will fit between the forks it is a bit too tall with the current tire. The Triton frame was custom built with this wheel as well as a uber-wide 29" setup in mind.

I am probably going to make another tire that is a bit smaller and will fit in a 07 KH29 frame. It is a really fun “almost big wheel” and I will need to add some shorter pedal holes to those SINZ cranks.

More info here

I have a question about the UCM: Do you need to take the brake off the mount every time you change the wheel or will it come off without disassembling?

1mm disk clearance to the frame should be OK - I ride aproximatly 0.5 but stiffer frame.

when the disk is “polished” after some more braking , the “rub” should disappear.

you are right, the caliper must be seperated from the adapter to remove it from the rotor. Wheel swaps are easier with the weld on tab. Did your Triton come with the weld on tab?

All right! I took a longer (15 miles) ride with some steep downhills. The brake works great. The smoothness certainly the high point of having a disc brake and I wouldn’t trade back willingly to a rim brake of any kind.

A small downside is the very small range of handle squeeze from “no braking” to “a lot of braking” to “total-lock-up”. This actually screwed me up more in the ending of a downhill, where a small let up on the brake lever took the brake totally off and I almost had a UPD when the wheel flew forward.

Still, I’m quite pleased with the UCM and rotor and cranks and brake combo. And, yes, I know I need to secure the brake cable better.

Uni: KH29
Hub: Schlumpf Muni hub, older generation, serial #114
Handlebar: Nimbus Shadow
Brake: Gusset Hydro Chute Disc Brake, with Mountainuni Unicycle Caliper Mount
Brake Rotor: Mountainuni Rotor (HELL YEAH BABY!)
Cranks: Sinz 140mm
Pedals: Wellgo
Seat KH Fusion Freeride
Tire: Big Apple 2.0

It looks like there’s a bit less than 3/4 inch of space between the spokes and the brake body, but I could move the brake to right on the caliper another RCH or so, and mess with the rotor spacing accordingly - please see below…

Where do I get these clips?

got 'em on ebay (actually they’re 3/16")
3/16" Nylon Line or Cable Clamps Package of 20 for about 5 bucks shipped.

they’re ever so slightly small for the hose diameter so it give it a little clamping pressure. just enough to keep it from slipping.

Edit: I used m5x10 taper head bolts to secure them to the Maggie mounts


Quad QMD-6 with UCM and Schlumpf hub

Thanks Steveyo for doing the test run and providing all this info.

It looks to me like the Quad QMD-6 mechanical caliper might just barely fit with the UCM and a Schlumpf hub.
The QMD-6 is 37.7mm from outside (i.e. wheel side on a uni) of caliper to the disk, as I posted back on page 50, post #736.
37.7mm = 1.4842519685055402 inches; with at least a little room for clearance, let’s call that 1.5 inches.
From your photo, it looks like your current setup is about 1/8" shy of this needed clearance, or about 3.2mm.
So, if the disk spacers were moved to the other side of the crank, that should move the disk out 4mm, which means there should be, just barely, sufficient room for the QMD-6 (although there will probably need to be spacers on the UCM as well). I also understand from a prior post that you’re using a 6mm crank spacer, right? So it may also be possible to add a little more clearance distance by using an 8mm crank spacer.
There should be less of a clearance issue with a standard hub, so for use on a standard hub, it does look like the QMD-6 is a viable option.
(Feedback on my figures and reasoning appreciated!)

I’m liking the idea of a mechanical caliper for a few reasons. First, I think the mechanical modulation is probably better suited for uni use; we don’t need a super strong brake and it shouldn’t have the on/off tendency of hydraulics. Second, they’re easily adjustible and serviceable in the field. Third, the parts: it’s much easier to do a custom cable length setup, cable is more durable and can’t spring a leak like a hose, and it’s very easy to replace broken handles. Fourth is that they’re a lot cheaper, but that’s not a big factor for me on this topic.

I may end up being the guinea pig for the QMD-6/Mountainuni rotor/UCM/Schlumpf. My slight remaining concern is about using a crank spacer on the hub and the effect on the c-clip and groove for the clip – concerns that have also been expressed by others. I’m not entirely satisfied with the response on this issue (see post #825), and I’ll probably wait until we actually get some feedback from Florian Schlumpf. I might end up writing to him myself, but I’m not really in a hurry, and will need some time getting used to the hub before I’ll need a brake anyhow. It also seems more appropriate for the Mountainuni folks to get the official word, seeing as how crank spacers are a critical compatibility issue for using the Mountainuni system with a Schlumpf hub.

OK, so I tried to read most of this thread, but I did a lot of skimming as it is crazy long. Long story short is that I’m getting a Schlumpf that should be here within a few weeks. It’s going to be in a KH36 for the most part, but it might migrate to a KH29 or KH24. I want to get the MountainUni/UCM/anything else I need in order to set this up. Can someone tell me exactly what I need, how to buy it, and the approx. cost? Do I buy the Sinz cranks separate, or from mountain uni? I would probably want 140mm or 145mm. Sorry if these questions have been answered in an earlier post, I tried to read the ones that looked useful. Thanks!

Edit: Another question, I thought I read in an earlier post that you have to set up the Schlumpf “backwards” in order to have the knurled bearing not interfere with the UCM. Is this true?