Hey all!
Some photos are here (http://www.unicyclist.com/gallery/albup13) of a 700c unicycle designed for street riding. It has a drag brake and, with a change of tire, is suitable also for off-road. Questions and comments are welcome.
Thanks to Alan Schaeffer and Dave Miller of the Ordinary Bike Shop for their knowledgeable and helpful support.
Do you find your legs scraping against that hardware? it seems to stick out quite a bit
Not at all, though I admit I was bundled up - the snow was a flying! Leg clearance is the primary reason for putting the brake on the back side. The big loop of cable will go away, but I didn’t notice it either.
Bikes and Motorcycles use their front brakes for 75% (approx) of their braking power, maybe you should move it to the front
The reason two-wheeled cycles of the horizontal kind use primarily the front brake is because, when braking, the mass of the rider and cycle torque around and put more pressure on the front tire-road boundary. For a uni this is not true, so the primary reason for the rear placement is leg clearance.
If you look at photo 1, though, you’ll see that the brake is actually quite tidy sideways.
http://www.unicyclist.com/gallery/albup13/Brake_from_front
The cable end could easily be turned the other way if necessary.
I was kidding about the front/rear positioning. I forgot the 
Looks good (I just thought it looked like it stuck out far enough to bother you, is all)
It looks great! How much does the break help? What kind of frame is that? How did you get the post for the brake handle attached to the uni? What is that post made from? How many other people have managed to make this type of setup?
I think one of the most asked questions when I ride is “how do you stop?” I guess this would be the answer.
Did I mention that it looks great?
Daniel.
LOL, Sofa. Well I’m too serious anyway. Thanks for the intent!
daino - thanks, lots, Sem XLW 28", drilled a hole in the frame, it’s a MB bar end and slips over, you buy a pair of MB bar ends and use only one (this is a longer one), Yes you did, and thanks again!
The brake is helpful for a) safety on down hills with short cranks, b) on longer trips when you’d rather get the work out of the hill that you put in, instead of doing leg presses all the way down, c) as a really handy parking brake.
Hey, great looking rig. What hub are you using, and what’s the deal with the washers between the hub and the spoke head??
Also, how wide is the rim you are using? My 36 hole Suzue hub will be here Friday for my 29er project. I was going to just use a regular width road bike rim I have, but the bike shop guy insists that I use a Rynolite. I don’t plan on riding mine too hard, just commuting and easy trails.
I’ve been thinking of using a big caliper brake like that on my Coker if I can find one with enough reach. I just always figured a v-brake was over kill on a road machine.
later potaters… Mojoe
another reason you want the brake behind the frame is because if you’re stopping from going forwards fast, or braking downhill you want the brake to be being pushed into the frame rather than being pulled off it.
I wonder if an old centrepull brake would have a bit less stickyoutness, or if v-s / cantis would?
Obviously putting canti bosses on would be lots more work though.
Sarah Miller and Paul Selwood have big caliper brakes on their cokers, attached in a similar way, using thumb shifters as the lever.
Joe
I put a modern variant of the centre pull on my old muni. It was very nice, didn’t stick out at all.
Thanks for the comments!
Mojoe -
It’s a Suzue 36.
The washers are to better support the spoke heads. This procedure helps the truing procedure, helps the wheel stay true, and helps minimize spoke movement. It takes extra time, and costs more, but is worth it.
The rim specs on CR18 and Rhynolite are here: http://www.sun-ringle.com. Under showroom/road. For primarily road riding, the CR18 matches the Top Touring tire better. As you can see from the diagrams, the main difference is width (and hence, mass/weight), not construction or design.
There’s a good thread up now too on 700c rims.
This brake had the reach without requiring huge mods to the frame. It also will reach around larger tires such as the NanoRaptor. It’s a BMX brake.
Joe – I’d agree with you on the reason except that front brakes on a bicycle are in front of the frame, and as Sofa pointed out, they handle most of the braking. Moreover, on a uni, you would never put the force on a brake that you have on a bicycle, at least for road riding. Trials riding with brake use would be different.
I’m going to use a Mavic CXP21, because it’s what I have laying around, and I’m trying to do this project on the cheap. My rim is only 20mm outside width. It may be a problem with the Nanoraptor, but I’m going to try it. Not planning on doing any side hops with the 29’er anyway. I’ll get the hub tomorrow and I should be able to build the wheel this weekend. For now I’m going to use my Coker frame with this wheel, but I’ll get a Yuni frame for it next month or something.
Mojoe
Any idea if a brake like that would fit around a halo combat rim with a ception (2.6") tyre? I’d like a brake on my muni, but I don’t want to spend £100 for the brakes, plus a bit more for having brake bosses added. Aslo, what’s the modulation like with side pull brakes?
Cheers,
John
Based on trying to squeeze in an unmounted Kenda Kolossal 26x2.6 in, no. The tire seems to fit in ok, but there is very little clearance. When you actuate the brake, it appears as though the brake would hit the tire before it hit the rim.
I couldn’t test the brake fully because of the weather, but on the flats the modulation seemed surprisingly good for an inexpensive brake. As we get more time on the uni, we can post more feedback.