Hello everyone. I have been considering putting a disc brake on my 26” Nimbus MUni, but since I have never used a brake on a unicycle before, I am not quite sure what I would want for this application. Should I use dual piston or four piston brakes? On a bike I would go ahead and throw on the extra braking power because you might need it and it won’t hurt, but with the unicycle I have reservations. With the low speed, highly sensitive application in unicycling, would the extra pistons be helpful? Could they actually be harmful in learning how to brake on the uni due to the additional sensitivity? Would I ever find the extra stopping power useful?
These considerations also make me wonder whether I should use a cable actuated brake or a hydraulic one. I am familiar with both on bikes, but how do the braking characteristics of the two systems lend themselves to MUni use? Is it worth the hassle and cost of hydraulics? I am open to any advice you guys have to share on selecting and installing a braking system on a unicycle, because it is new to me.
With a brake on a unicycle it depends what kind of riding your doing really , you will get many different ideas from people as to there preferences.
Personally I would as it’s your first brake go for a second hand 180mm rotor and a cheap second hand hydraulic shimano two pot and go from there.
I assume your nimbus has a disc hub ? Don’t also forget you’ll need a mount for the lever under the seat.
I don’t see hydraulic as a hassle over cable disk brakes, if anything the opposite since they don’t really need readjustment for pad wear. Same for cost, the cheap Shimano hydraulics are the same price as cable disk brakes last time I checked.
+1 for cheap second hand 2 piston Shimano as a start, at least if you are mechanically competent and can judge a brakes condition when buying it. At least in my area, there are usually some take offs from new bikes in good condition on the local classifieds.
Thanks for the advice. Mechanical competency is not a problem. I do all my own bike maintenance, and I am an industrial mechanic by trade. I just find hydraulics to be a nuisance to bleed, and generally enjoy the tactile feel of cable actuated brakes. That being said, I do acknowledge the allure of set and forget. I suppose my preference is more of a purism thing than anything, so there isn’t much to say other than bah humbug. If the hydraulics are genuinely better in this application, then I will set aside my Luddite tendencies and get with the times.
As for parts selection: Used bike parts are few and far between in my rural area, so I would probably just order a new set. In summary, hydraulics are worth it and 4 pistons are not, at least not for a beginner on uni brakes. I am generally a SRAM guy, but you both recommend Shimano, so I will look into their offerings. This is good to know, thank you both.
You may need to go hydraulic depending on the set up you have. I tried Shimano and Avid mechanical calipers on my nimbus muni and the caliper is too wide to fit between the frame and the crank, but I have a d’brake and spirit cranks. No issues with a hydraulic brake. I’m not sure if an inboard set up would leave more space for the caliper to fit.
I have a basic Shimano mt200 two piston with a 160mm rotor. It’s enough to take the strain off my legs and smooth out the steeper descents. I use it mainly because I had it spare, but also because I thought a more powerful brake would just tip me off the uni. I may upgrade as I get better, but it’s certainly enough for me for now.
I also have a cheap Chinese cable actuated hydraulic caliper on my 29 and it’s fine too.
One more thing to keep in mind, if you do lots of long descents where you will be dragging the brake for a long time, a 4 piston with a bigger rotor might cope with the heat build up better.
Oh, and since you mentioned bleeding and Shimano Vs SRAM - go with Shimano. They use mineral oil as opposed to the dot fluid SRAM use, it doesn’t attract water the way dot stuff does therefore doesn’t need bled anything like as often, and personally I find the bleed process much more straightforward with Shimano anyway. Pretty much once you cut the hose and bleed it you won’t ever need to touch it again.
@OorWullie Good to know: thank you. I have only ever used SRAM and Campagnolo hydraulic disc brakes. My all time favorite disc brakes are Yokozuna Mokoto or Ultimo brakes, because they are the best of both worlds, IMO. I didn’t consider them for my MUni because it would be silly to spend more on the brake set up than I did on the unicycle itself.
I suggested 180mm rotor because with smaller rotors you might get an issue with the wheel spokes clipping the caliper , Having a larger rotor moves the caliper out further to prevent this.
As mentioned shimano use mineral fluid instead of DOT fluid like cars/motorcycles use which means not needing to be as careful when bleeding, You can just use a standard hospital type syringe (100ml) and bleed from the caliper down low and the lever high with the hose as straight as possible pushing fluid up and out.
You can get a small 5mm fitting to screw into the lever bleed port so you can attach a tube to catch the bleed fluid into a pot , Or just let it run out over the lever and then do a good clean up in soapy water once nipple and lever bled cap are back on.
Ebay is a good source of used brakes.
@m00ms i didn’t consider the spoke issue. That is the kind of thing that would be likely to bite me in the backside with this project, so I appreciate the heads up. I have a 180 lying around, so will go for that first if I pull the trigger on this build.
@Tripthebalance I don’t have a picture, but I am ready to go should I choose. I could even run the disc externally if I really felt like it, because the previous owner also installed Spirit cranks.
To echo the others: I would recommend a mid-range Shimano two-piston caliper and a 160 or 180 mm disc. I use a Shimano BR-MT500 caliper and a 180mm disc on my 27.5" muni, braking quite a lot in steep terrain, and have never seen the point of a more expensive brake.
The Shimano hydraulic oil can be quite expensive and/or hard to find. I, and many others, use Citroen LHM+ hydraulic oil – it has exactly the same viscosity, is easy to find, and costs half as much.