Customer Reviews
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.
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 Disc
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 discs 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
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.
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This reveiw came from Scott Wallis, who installed the Mountainuni System on a Custom Framed 36" Square Taper Nimbus Hub. We appreciate the time he took to decribe the overall inital experience and feedback on the installation . If you have a review that you'd like to submit to us for posting either on our Blog or Reviews page, please let us know. We are very happy with the initial feedback we've received, as it provides key insights to revise and improve our System, and to be more compatible and universal across all unicycle brands. Thank you for you interest in Mountainuni System Reviews!
Installation
I installed the 150mm, square-taper version of the MountainUni disk conversion on my 36" custom frame uni with a UDC Wide hub. I did the setup and welding work just as outlined in the Mountain Uni instructions. My frame is a chrome-moly steel multi-tube prototype, and I TIG welded the supplied mounting tab onto the frame. Rather than checking into what brake sets had been successfully installed with the MountainUni conversion and getting one of those, I decided I would use what I had laying around, which was a used Magura Julie rear disk brake assembly from around 2005 bought on Ebay several years ago. This Magura had an IS mount, no adapter. The installation went well but required a few small mods to use this particular brake. There was not quite enough clearance between the lower lug on the caliper and the disk mounting bolt so I ground some of the lug thickness off, roughly 2mm. Also, the Julie pads have two small tabs on each pad. Only one holds the pads in place, the other is there for using the same pad for either in or outside the caliper. The unused tab interfered with the crank spider, so I ground them off of both pads. The outboard surface of the caliper body on the Magura Julie has minimal clearance between it and the inner suface of the crank, but enough to work fine. The disk came with several shim washers between it and the spider and if it wasn't for those, it wouldn't clear.
The Test Experience Story by Scott Wallis
It had been several months since I had ridden my 36 on rough offroad terrain. For the last several years it has been my prefered type of riding, but due to some injuries and commitments, I had been away fromriding for a while.
Feeling pretty rusty, I started off on paved trails and practiced lightly applying the brake while cranking to get the feel for its stopping power and modulation, keeping in mind that the disk and pads would need a little time to seat in to each other before the action would become consistent. Everything felt great from the start, though the lever position and feel did change during the wear-in period.
With the brake functioning smoothly and having some paved grades under my belt, I headed for a steep nasty downhill singletrack. I didn't yet have enough confidence for the stair-steppy rock top section of this hill, so I dismounted and walked down a level to where the trail switched to a narrow and very loose dirt/ gravel track that threaded through large trees atwith slight fall line to the hill. This trail is always a little dicey when the ground is dry and loose like now, because the slightest over-application or brake grabbiness will cause the wheel to wash out. In short, the perfect hill for perfect brakes. As I prepared to go down, a small boy and his dad crossed the trail at the bottom of the hill. Now I had an audience. I mounted into a stillstand, made one small balance hop to get situated, and headed down. I started applying the brake at the very beginning of my decent so I could modulate it better, not having to anticipate where the braking would begin. Wow, was it smooth! I descended quickly and in complete control. I was stoked, and my audience was clearly impressed judging by their enthusiastic comments as I went by. I gave them a casual smile and wave and blasted away. Move along, nothing to see here...
After many similar episodes, I have to say the brake works perfectly. I have done a lot of work with Magura rim brakes on unicycles, including building a machine to grind the braking surfaces of 36 inch rims. When everything is perfect a Magura works quite well, but they don't stay consistent especially in offroad conditions where the Magura's are sensitive to grit, tweaked rims, and flexing frames. The MountainUni disk setup should be far less sensitive, even impervious, to these issues. The disk could be vulnerable to a direct rock hit, but so far it doesn't seem like that is a big risk, especially on the bigger wheel sizes. I have some concern about the fact that the disk-to-caliper alignment is affected by how far the cranks pull onto the square taper when tightening. For this reason, be sure you tighten the cranks sufficiently when you install them, before setting up the caliper mount. Personally, I always use a torque wrench and tighten to 40 ft/lb and recheck after almost every ride. A good practice would be to install and torque the new cranks, ride it around, hop, etc for a while, then re-torque before doing the setup for the welding operation. This way it should be seated well enough on the hub taper that subsequent tightening won't move it in much, if any. Something else I did was to put several thin washers between the brake caliper and the mount tab. This way I can remove washers if needed to realign the caliper if the disk does move in due to square taper deformation in the cranks over time. I was afraid the setup would have increased "Q", wider spacing between the pedals. It turned out to be 10mm or less wider than my existing setup, so not noticeable at all. I also thought my foot would drag/catch on the caliper, but it never touches it. Even the brake hose which is connected to the outboard side of the caliper seems quite safe, though I do plan to relocate it to the inboard port for cleaner looks and a little more protection.
In summary, the Mountain Uni brake disk kit worked great and I now consider a disk to be the way to go for brakes on a 36. I will have to try it on a smaller MUni wheel next.
Thanks,
Scott Wallis
Wallis Designs , Inc.