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I would like to replace a set of Weinmann brake calipers on a Raleigh ladies' bike with newer, modern and more efficient calipers like a dual-pivot one. The problem that I have is that the cable to the rear caliper is routed from the bottom, as seen in the attached images. I have not yet managed to find a suitable dual-pivot caliper so that it would accept the cable coming in from the bottom and not from the top. Do you know of a caliper that would do the job? Any advice, help and/or suggestion would be greatly appreciated. Image 1 Image 2

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  • Kind of need to know the brake reach needed to answer, although I'm guessing 56-57mm. (Vertical distance from center of brake track to center of brake mounting hole.) Tektro does have some extra long reach (their site says 61-81mm) dual pivot brakes that can be set up for this kind of routing.
    – Nathan Knutson
    May 2, 2017 at 2:47
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    Do note that you could probably reroute the cable so that it comes in from above. It would sort of wave in the breeze below the seat, but with a little care should not get in the way.
    – Daniel R Hicks
    May 2, 2017 at 2:57
  • I think if it were me i would reroute the cable, they make bolt on cable guides that could provide a clean finished appearance. Just run it up the seat tube and then down the seat stay and get a new caliper.
    – Nate W
    May 2, 2017 at 23:24
  • @NathanKnutson. The existing Weinmann reach is 55mm, with a tolerance range of 45-65. I think I will need a 'long-reach' caliper.
    – Adrian
    May 3, 2017 at 18:08
  • @DanielRHicks. Yes, I think that is it. Thank you all.
    – Adrian
    May 3, 2017 at 18:21

3 Answers 3

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Honestly, the back brake contributes so little to braking that its not worth fitting a dual pivot.

I'd simply change the brake pads to Kool Stop, maybe run a new inner and outer cable, and leave that single pivot in place. Clean the rim's braking track too.

Dual pivots tend to be more speed orientated, which means racing frames and cables that go in the top. A mixte or ladies frame is not speed focussed. So a bottom-entry dual pivot rear brake caliper would be a rare duck.

You might be able to find some kind of pulley, but for a low-end steel MTB-BSO, new brake pads+cable will be a substantial braking improvement by themselves.

To answer the question - consider using a dual pivot caliper with a travel agent like this, to get the cable around 90 degrees of the bend. I couldn't find one with "more turn"

enter image description here

Web site says "To use our Travel Agent as a friction reducing roller simply route the cable on the outer edge of the wheel and it is smooth sailing for your brakes around tight bends"

From http://problemsolversbike.com/products/brakes/travel_agents_-_6416

Not ideal, but here's a lady's frame used with cantilever brakes and a pulley hanging off the seat clamp, to give some ideas. This would not really fix your problems because the cable still faces upwards. enter image description here

If your bike had the middle stays, like a mixte frame then this would be ideal. Using the existing caliper too. As per @robokaren idea, this might work down at the chainstays, given enough washers. enter image description here

Finally consider running full housing down, up, and down into your dual pivot caliper. The friction will be higher, but if you use non-compressible housings with teflon then it will help. A couple of cable clamps to hold the outer in place could be useful too. enter image description here

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    Hi there, Thank you. Believe me I've changed the pads, inner/outer cables, washers and everything else that I could think of. There's a problem/design flaw in my opinion on these bikes in that the cable routing to the rear brakes makes it easy for water to ingress the outer cable. Over time, it gets very sticky and makes it difficult and rather annoying to operate the brakes. This is the primary reason that I thought perhaps a dual-pivot could do a better job.
    – Adrian
    May 2, 2017 at 1:59
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    @Adrian - Yep, I see the problem with the upward-facing cable quite often on stunt bikes with the 360-degree fork. The cable typically goes down through the middle of the fork and then turns up to the front brake. Even though the rear cable is 4 times longer and much more complex, it's the front that quickly rusts up. Replacing the caliper won't fix this -- you need to regularly lubricate the cable, and try to keep it out of the rain.
    – Daniel R Hicks
    May 2, 2017 at 2:52
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    Good quality MTB cables that come with seals will help keep the water out. A cheaper way would be an O ring under the end ferrul, add a rubber boot as used in V Brakes on MTB's and you are a long way to keeping most of the water out.
    – mattnz
    May 2, 2017 at 3:24
  • @Adrian sounds like you might be throwing good money after bad. If its a steel wheel rim then replace the whole wheel for improved braking. At some point you should look for a good (better than that) used bike and allow your ladyfriend to ride a nice bike. Or simply fit the good front brake and teach her better braking technique (ie, off the saddle, bum back and low, straight arms, and hard on the front brake while maintaining balance.) Otherwise add silly and excessive amounts of grease to the cable ends, or even put a "water drain hole" in the lowest point somehow.
    – Criggie ♦
    May 2, 2017 at 7:56
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    @Criggie. Yes, I agree, agree, and yes. I've already upgraded the wheels. I will look to replace this bike [would be a shame, because, apart from the user and her braking techniques, it is solidly made and nothing wrong with it] I know things have moved on. Greasing, I've done and did not work. The drain hole not yet, but suspect that it would not work because of the amount of rain and the dampness in the air. Thank you.
    – Adrian
    May 3, 2017 at 18:32
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A third (non-optimal) solution is if you are going to replace the wheel and hub anyway is to get a disc brake compatible rear hub and a rear disc-brake adapter..

Rear rotor adapter

With said rear wheel disc brake adapter, a rotor, and a cheap set of mechanical calipers -- you're all set.

Rear rotor adapter on bike

This would only make sense if you were replacing the wheel and brakes anyway. Normally discs on the rear are pretty senseless because most of the braking is from the front, but it might be the easiest, cheapest, and most powerful solution here -- if you're already replacing the wheel.

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  • Where would the disc caliper mount to on the frame? One could get a disk brake mount welded on the frame, but that would be costly and there's no garauntee that the frame would hold up properly to the stresses of disk brakes.
    – Kibbee
    May 3, 2017 at 19:01
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    There are bolton adapters. I'll post when I get back to my computer.
    – RoboKaren
    May 3, 2017 at 19:32
  • This particular adapter is sold from a chinese vendor for about $4 but you can also get them at the giant auction site in the sky.
    – RoboKaren
    May 3, 2017 at 20:47
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One other (non-optimal) solution is to move the brakes to your chainstays by using the bracket and hole that is there normally for the kickstand.

It's not optimal as that location gets dirty and is hard to adjust the brakes. It's better on mixte designs that have a middle set of stays between the seat and chain stays.

You may need to make a simple bracket out of plate steel or aluminum so that the caliper is at the right place.

lower bracket adapter

Note that you can adjust how close the calipers are to the wheel by varying the distance between the holes in the plate. This means you can use very short reach caliper brakes. Because short reach means higher leverage and because this placement has the shortest and straightest brake cable distance of your other caliper options, you should have the most powerful braking that you can get from a caliper brake -- assuming dry conditions. In wet conditions, the brakes may get so much water kicked up from the front tire to negate this advantage.

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  • Thank you. Yes, I've already looked at that but it needs modifications and/or welding. I will try to find a way to feed the cable from the top. thanks again.
    – Adrian
    May 3, 2017 at 18:35
  • If one were sufficient motivated, all it would take is a piece of sheet steel or alu bolted to the center stand hole with another hole in the right location for the brake caliper.
    – RoboKaren
    May 3, 2017 at 18:38
  • I am sufficiently motivated, with time on my hands. So, I shall look at your suggestion when the new caliper has arrived. Thanks again.
    – Adrian
    May 3, 2017 at 20:17
  • I like this as a solution - worth trying and if it fails then the caliper can be removed, cleaned, and returned to the original location.
    – Criggie ♦
    May 4, 2017 at 20:44

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