Mountain Uni Disk Brake System

[saskatchewanian]

I have been using a Mountainuni disk brake system for about 8 months now and figure it is time to write a review. For the quick version skip to the bottom


First impressions when I opened the box were not really all that great. They were poorly packed and didn't have an even number of spacers on all the bolts. The packaging has since been improved and I think the spacer thing was an anomaly (I had the right amount, just not evenly spaced).

There was considerable confusion about what adaptors were needed to make the MU disk system work with various frames. I had a custom Triton frame with disk mounts and Hayes Stroker Ryde disk brake with a 180mm front/160mm rear adaptor. I was able to make the adaptor work flipped upside down but it wasn't ideal. I found out later that I needed a 160mm front adaptor for a welded on mount.

Once it was set up and I was able to go for a ride all that tinkering and fooling around with spacers suddenly felt worth it. It was the buttery smooth braking action I had been looking for.

I set up a few wheels with disk cranks to work in the frame but was unable to make my Schlumpf wheel work with the flared out Triton frame (though it worked in a KH frame) It was great to be able to switch wheels with ease and not have to move the brake. It was also great to be able to have a brake with my 32" wheel since there is no frame with brake mounts in that position.

I moved the Hayes brake to my 36" frame with a UCM adaptor and setup a Shimano M775 brake on the Triton for CMW. Unfortunately I could not mount the Shimano brake lever in my preferred position on my muni bar so I used the 36" frame with Hayes and UCM with my 26" wheel for the weekend and had flawless performance (once I got clearance issues sorted, ended up filing down the pad retention pin to eliminate rubbing)

I used the Shimano M775 on the Triton for a very short period of time and had much better power than the Hayes Ryde but swapped the brakes to use the MUni bar on the Triton.

I did fade out my brake while doing "Braile" near Sant Cruz and crashed pretty hard bending the left (non disk) crank. I was disappointed but not all that surprised that it bent since I had drilled a few extra holes in the cranks for multiple crank positions.

I appreciated a little bit more power from the M775 brake on the 36 but after a few good descents the brake developed an awful shutter and the disks seemed to be getting gauged by the brakes leaving distinct groves. I tried a few things and ultimately fixed the problem by changing to "organic" pads instead of the metallic pads that came with the brakes.

The M775s with organic pads work great and are absolutely silent when braking which is nice. The groves in the disk left by the metallic pads seem to be smoothing out, and modulation is better than ever.



The disk

The disks seem to be a tad wider than the standard disk. This is probably a plus in the long run as they will last longer that way but it is hard to set them up so they don't rub. I also wonder if the steel used is a bit softer than standard as I quickly wore groves in the surface with metallic pads in the M775 brakes.

The disks are built pretty beefily. The one on my MUni took a direct hit on a rock during a crash and it was just fine, a standard disk probably would have bent from an impact like that.

4-Stars


The cranks

I have multiple sets of SINZ cranks most of them with extra holes drilled in them for multiple pedal positions. I would not suggest doing this as the SINZ cranks might be strong enough out of the box they get flexy with extra holes in them and can bend at the new pedal hole. I have 4 sets, bent two (but both were multi-drilled)

The cranks themselves feel good with nice Q (same as KH) and are a very nice shape for shifting on a schlumpf hub.

3-Stars


UCM

The bearing cap mount in pretty ingenious. I think it is too flexible for use with metallic pads in M755 and equivalent brakes. It works great with the less grabby organic pads though, which have a better feel anyway.

It is too bad you need to take the calliper off the UCM to get the wheel out but it is not a big deal if you don't take your wheel off often. The UCM works with a 180mm front/160mm rear adaptor.

4.5-Stars


Hayes Stroker Ryde brake

Fairly weak brake that lends itself well to unicycle use. Doesn't have great power but is very smooth and has good modulation. Has a 2 piece clamp on the lever mount which allows you to mount it anywhere you have a strait piece of 22.2mm pipe without having to slip on.

3-Stars


Shimano M775 brake

This brake has much more power and great modulation if a bit grabby on initial braking with metallic pads. Too much brake for the UCM on a 36 with the metallic pads but when "downgraded" to organic pads they were buttery smooth.

The clamp on the lever is sort of bulky and might prevent you from properly mounting under the saddle.

4.5-Stars


Overall the whole system works as advertised and you will be able to experience buttery smooth braking on your unicycle without having to resort to re-building the wheel with a disk hub. (and you would need a UCM or weld on mount anyway).

It can be a little bit fiddly on initial setup but well worth the effort.

Overall I give it 4 Stars.

[Smilymarco]

+1 for the braking-power -> i love it! Best brake ever and i'll never switch back to a rimbrake

BUT....

i HATE the Sinz-cranks... i use 140mm ones on my 26" Muni.
They are way to weak for me... i only weight 70kg (with clothes and stuff) and they are bent like hell... only doing drops to max. 1,5m with sloped landings...

I know im not easy on my stuff... but they bent very very fast (third weekend of riding with them)

[kb1jki]

Originally Posted by Smilymarco

+1 for the braking-power -> i love it! Best brake ever and i'll never switch back to a rimbrake

BUT....

i HATE the Sinz-cranks... i use 140mm ones on my 26" Muni.
They are way to weak for me... i only weight 70kg (with clothes and stuff) and they are bent like hell... only doing drops to max. 1,5m with sloped landings...

I know im not easy on my stuff... but they bent very very fast (third weekend of riding with them)

check out the mountainuni disk brake thread to see the evolution of the product...

[Imob123]

very nice i like it

[svzurich]

Bump! Sorry for the necro, but I have a few questions.

Saskatchewanian, I have ordered KH Spirit cranks and am hoping to avoid replacing my new KH26 frame that lacks the disc brake mounts. I am hoping to order the UCM and the 180mm standoff to use with a regular 160mm bike disc brake.

Do you think that would work well? Even with a KH/S hub?

I am trying to approximate the mounting of the new KH frames without buying a new frame or grinding/welding the old one.

Kimmie, still learning this stuff and wanting to go disc.

[turtle]

UCM, spirit cranks and schlumpf hub can work, maybe you have to modify the bearing holder on the disc side (because the screws from the disc will touch the bearing holder...


I ride my triton (with disc brake mounts) with the schlumpf hub, spirit cranks and a 180mm rotor (magura disc and a avid brake)

[svzurich]

Thank you, Turtle.

[saskatchewanian]

svzurich: Everything should* work together but you will need a 160mm front adaptor/standoff if you are planning on using a 160mm disk.

Like Turtle said you might have to shave off some material from the bearing holder on the frame for the disk bolts to clear.



*cranks tend to go on the schlumpf axles further than most, this may cause clearance issues for the disk bolts. A spacer might be necessary to prevent the crank from creeping on too far which is not endorsed by schlumpf but has been done by quite a few people without incident (as long as you only "snug up" to the spacer and not tighten down hard against it)

[svzurich]

Thank you! Placing an order for the UCM v2 with 180 adapter now.

Kimmie, hating the idea of buying a new frame for a 1 month old uni.