1

I have a cargo bike equipped with a Nexus 3 hub shifter and related roller brake. Since where I live is pretty hilly, I'd like to replace it with a shifter with a big range and little gap between the gears, as the 11 speed Alfine hub shifter. Unfortunately, the Alfine is available only in disk version, while my bike doesn't have mounts for disk or v-brakes. Moreover, the bicycle has poor braking performance when fully loaded, so a disk brake would be a valuable addition.

rollerbrake mount

Is there any adapter I can use to mount a disk brake caliper on the rollerbrake mount? Are there chances that the bike present clearance problems while trying to mount a disk brake on it?

Update: In the end I mounted a Nexus 8 shifter with its own brake. The rollerbrake sold with the nexus 8 is the one with heatsink fins and, after some months of use, I can say it offers a lot more braking force than the one that comes with Nexus 3. The braking performance of the rear wheel is now comparable with a good disk brake (with less, but overall sufficient modulation). Adding the proper braking grease increase the modulation. I can warmly recommend this setup to anyone has similar constraints.

Improve this question
3
  • Not an answer, but I have an alfine11 with a centerlock disk mount, and its working fine as a rim brake wheel. I've just left the rubbery cover on the centerlock connector to protect it.
    – Criggie ♦
    Feb 1, 2019 at 22:39
  • 1
    Thank you, Criggie. Unfortunately, my bike's frame doesn't have the v-brake mount...
    – penguin86
    Feb 2, 2019 at 11:28
  • Could you fit a caliper rim brake? A decent dual-pivot caliper would be fine. Possibly tyre width could be an issue.
    – Criggie ♦
    Feb 2, 2019 at 11:49

2 Answers 2

Reset to default
2

I think your next point of call will be to speak with a framebuilder local to you. The chainstay has the big tab for your roller brake, so the chainstay is beefy enough for that. Whether that translates to being enough for a disk brake, I can't say.

What you need is a pair of brake mounts brazed onto the bare metal, and perhaps a brace up to the seat stay to spread the load. Once welded in it needs painting too.

If you go this route, consider what else you might want done to the bare frame. Do you need additional mounts for racks, bottle cages, brake lines, etc? If so, get them all done by the frame builder in one visit. You generally have to strip your frame completely for work like this.

Does your fork have a disk brake mount? If your bike has front suspension, its even more work to weld/braze because of the suspension. If you have a rigid front fork, see what your frame builder says. but often the front tines are too weak to take a disk brake and you have to buy a stronger fork anyway. However if the frame builder's got a painter, you might want them to paint your welds and the new fork so they all match.

Improve this answer
2
  • Thank you for answering. I accepted this answer for being the most argumentative. Having the frame modified, unfortunately, is not an option for me: the cost would be not worth, considering the frame value. Seems like i have to stick on the roller brake...
    – penguin86
    Feb 4, 2019 at 21:42
  • @penguin86 Roller brakes are fine - you may need new brake pads/shoes in it, and possibly a degrease. I had a band brake where someone had oiled it to stop the squeal. Also stopped it from working completely :-\ Anyway - adding a front disk brake will help to some extent, but less so than on a conventional bike.
    – Criggie ♦
    Feb 5, 2019 at 2:56
1

I have only seen disk brakes used on frames that are designed to take them. Seems like you don't have the correct angle or spacing in your drop outs to mount a brake caliper, and drilling into the frame to fit it isn't a good idea.

The Envilo continuously variable transmissions work with roller brakes https://www.enviolo.com/en/groupsets/City

Improve this answer
1
  • I'd like to vote up this answer, but my reputation si not enough. Thanks for answering, btw. Seems like I'm stuck with roller brakes if I don't want to have the frame modified. My bike uses an entry level rollerbrake (Shimano Inter M, the one sold with Nexus 3). I wonder if the one sold with Nexus 8 is more powerful (I can see it has heat-dissipating fins)
    – penguin86
    Feb 4, 2019 at 21:38

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.