I’ve been fine riding a 24" wheel brakeless until recently when our dog has decided that when she’s on her harness running ahead of me she should power down hills faster than I can stop her with back pressure on 115mm cranks. So I’m thinking a brake would help.
I have old unis and am not looking to invest in a disc brake setup, but old Magura Rim brakes are available on ebay.co.uk quite often. Indeed I may hopefully be able to buy a bunch being sold as spares (but with enough working to provide for a unicycle wheel) tomorrow evening. However neither of the 24" frames I have has Magura mounts.
Since the spares I could buy include a couple of brake arches and both standard and Evo brake fittings (that attach to V-brake bolts on a frame) it seems I could potentially add either v-brake bolts or Magura mounts to a frame. The latter would need welding on (I can buy the mounts reasonably elsewhere), but I’m wondering if it’s possible to attach a v-brake bolt in some way that doesn’t require welding, eg with some strong ratchet strapping, given that I’d use it with a brake arch for stability and wouldn’t need all that much braking strength anyway.
BTW Caliper brakes won’t fit around my tyre, and I’d prefer Maguras to V-brakes.
Does anyone have any experience or suggestions in this area?
I am a sucker for ebay bargains so I’ll admit that what I’m really hoping I can come up with a viable way to add Maguras to my frame (probably an old Nimbus X chromoly frame btw).
Thanks
If you are okay with drilling your frame, you could drill holes where the v-brake mounts are required and crimp in rivet captive nuts, then bolt the brake booster (the arch) to the captive nuts and hence the frame. These would be blind holes, so on one side of the frame only.
That might well weaken your frame a bit but might be preferable to having a through hole where you could just put a bolt through the frame. I don’t know if you frame is steel or aluminium, putting steel nut inserts into an aluminium frame might not be a great idea for corrosion though.
Drill a hole in your seat post tube above your fork and install a bmx side pull break. You will love it I have it on my udc 29 and 32. I like these brakes, I have them adjusted so they don’t grab, I can modulate my braking very smoothly. Old school brake for old school uni, easy DIY project and no welding.
Amazon has many to choose from like the one in the link below.
What tyre size do you have? I’m running a Schwalbe Crazy Bob currently (2.35"), but also have a Maxxis Hookworm (2.5") and a DMR Moto Digger (2.35" and more knobbly) that I would want to be able to use. I’m thinking calliper brakes like these won’t give enough width clearance and would also be reliant on the fork crown being the ideal distance from the rim position as the brake is positioned by the drilled hole location.
I’m riding a chrome Nimbus II 24" frame, but I’m thinking any mods for braking would happen as part of restoring a Nimbus X frame, which has an unusual fork crown.
I have the nightrider 32x2.25 on the 32. I have a maxis tire on the 29 I will check it when I get into work this morning and report back. I will send a few pictures
It’s a chromoly steel frame (see above - I’ll be cleaning it up) - I feel a bit insecure about drilling the forks, especially as I imagine the inserts need to be a good deal wider than the final bolt, but I’ll look into this more - thanks
Thanks, that’s really helpful to see. I’ll have to do some measurements and check the state of the fork crown for drilling. I can see those calliper arms clear your tyres OK, but I think one of mine (and possible future more aggressive tyres) would be less rounded.
On the 29 ER that unicycle came originally with a 1.95 inch tire. I rode this with an inova 2 inch tire for many years. If you can see from the picture that tire is very tight in the fork. My nimbus 29 road has much more clearance between the tire and the fork with a 2.5 inch tire.
I had a quick look – for an M6 rivnut the chart I was looking at said it was 8.8mm external diameter, so not too big a hole (~3/8"). You would have to be reasonably accurate and might need a thin spacer/sleeve on an M6 bolt as I can’t really remember the size of bare V-brake bosses. Since you have a cr-mo frame steel inserts would be fine – I only mentioned the issue if you had a aluminium frame for galvanic corrosion between the Al/Fe. I can appreciate that you might be nervous about drilling your frame and getting it right though.
You said you wanted to mount Maguras, so that approach would let you do that and not have any issue with tyre size (at least within the bounds of the brake booster) or frame size – mounting a side-pull calliper though a hole in the fork crown is a simpler solution for sure, assuming you can get a wide enough calliper with long enough reach, and that the brake performance is adequate for your needs, which it probably is.
Another solution is just to buy Magura braze-on mounts and get a frame builder to braze them on for you – it might not be too expensive in the grand scheme of things. I’m sure you’d be able to find a frame builder somewhere in your area.
I think I’m heading in that direction - it feels like a more proper solution, and in terms of vintage authenticity (if ever there was such a thing with a 20 year old unicycle frame!) it was the sort of thing people were doing back then - eg this old post with helpful input from @joemarshall (who I think even lived in the same town as I do now at around the time he posted that). I can get the Magura mounts for about £15 delivered, which isn’t bad (although I bought the unicycle I’m planning to fit them to for less!).
(which isn’t bad, either!)
How about a set of bolt on v-brake mounts? These are for 31.8mm diameter which may be too large for your frame but you might be able to shim it.
I could only find braze-on Magura mounts (also on eBay)
Ah, now that’s what I thought must exist out there somewhere, but that listing didn’t turn up in my searches. I’ll see if I win the auction, what’s in it, and then keep this in mind for a possible mounting method - thanks
There are still frames with magura mounts. 507 mm (24") Muni Einrad-Unicrowngabel, Stahl, schwarz - QU-AX, 40,90 €
V-brake clamp on + adapter to magura could work, but by the time all the cost of small parts are added up, you may end up at more or less the same price as a new one that is more guaranteed to work.