_ForceD_

I’m doing some work on this mixte for someone. They’re complaining about the rear brakes not working great. Understandable, and inherent for a mixte because of the weird cable routing. I’ve read that there is a device that clamps onto the seat tube, above the front derailleur, or above/below the “top tube” that the rear caliper can mount to, and thereby eliminates the big bend, and makes the cable straighter, and brake operation easier. Does anyone know where I can get such a device?





Dan

Andrew R Stewart 

Unsure what mounting location or method you're referencing. But first a term correction. This is not a mixte frame, it is a dropped top tube ladies frame. If it were a mixte there would be a third set of rear stays from the dropouts to the dropped top tube/seat tube joint. If it were a mixte the third pair of stays might have their own brake/fender bridge that a caliper might be able to be mounted on. However this location can sometimes result in heel strike of the brake caliper as it's would be closer to the feet.

My usual way to deal with this bike's rear brake is first make sure the cable is freely sliding inside the casing, especially through the casing loop that is just above the chain as this is where water will end up and cause rust. I strongly suggest both lined casing and stainless steel inner cable. The next is what most will think of as being first (and if it weren't for the low loop on the cable casing would be first) is to install good pads. True the rim so the pads can be set as close to the rim without rubbing as possible. Make sure the caliper pivot is freely moving with no slop between the arms.

If the rider must retain those unsafety levers (the secondary ones that look like old fashioned dental braces) at least make sure they freely pivot but still their pivot hardware is not coming loose.

After all that I hope the rider will become more confident in using the brake that might actually save their life, the front one. Andy (whose dominate hand controls his front brake)

ARider2

I would first change the cable and housing using good quality parts and also check the brake pads and replace them if they are old and hardened.

bboy314

Kool Stop Continental pads can go a long way with this setup.

mpetry912 

so this part might be what the OP is referring to.

you'll have to figure out a relay clip on the seat tube - should be doable - to route the cable up to this pulley

and then use a center pull brake.

if you don't want to go that route, then I'd suggest new housing for the part that makes the U - bend at the brake, and a new teflon coated cable.

Also adjust the tension nut on the sidepull brake to ensure that there is no play in the arms.

and of course the "safety levers" must go. they are more dangerous than none at all !

/markp

dedhed

I believe he is talking about an actual mount for the caliper not the cable.
Honestly from the look of that bike, I would venture it'll be a putter around the neighborhood type rider that the safety levers won't be an issue. Generations of kids survived riding with those even during the CSPC years of things like front fork wheel locks.

grumpus

I think the device you're referring to is a cable pulley that allows top-pull routing, this has no advantage for a sidepull caliper with swappable anchor points. The main problem with the rear brake on an open frame, particularly one that is used in all weathers or kept outside, is that the cable casing is a trap for water and grit. The solution is to clean and lubricate often. Some frames make this easy by having slotted cable stops, so you can pull the casing off the stop and slide it up the cable. Wipe the cable and smear grease on it, run some oil into the casing, refit cable. Or you might prefer to replace the exposed cable setup with full casing - this is less likely to catch water but more hassle to clean and lube.
​​​​​​Edited to add: I note the "suicide" levers - if she's relying on those instead of braking from the hoods or drops she might benefit from a flat bar conversion.

dedhed

And a stainless steel inner cable

veganbikes

Not just stainless but a good polished stainless uncoated cable and also good stiff compressionless housing. I would also go with Kool Stop pads. Normally I would say good pads and shoes but in the case of the Continentals or similar fitting pads they are all generally come as one piece (or metal shell around the pad)

Some people with odd bends also will use a linear pull brake noodle to help mitigate the issues.

Andrew R Stewart 

Not an answer to the OP's questions but this bike has one of the worst case brake systems that were far to common back in their day. Low leverage caliper design with thin and flexi arms, chromed rims, cable/casing loops routing that allows water/grime to enter the insides of the casing from gravity alone then sit and not evaporate off quicker then the rust can develop, secondary brake levers which can loosen on their pivot studs and also take up primary lever travel so that often the levers bottom out on the bars before enough clamping forces can be applied to the rim.

If the rider can't ride the bike with their hands on the tops of the lever bodies or in the drops with comfort and confidence I would say this bike's set up is wrong for that rider. It might well be the case that grumpus commented on, a switch over to flat bars might make for a safer bike for that rider. Andy

_ForceD_

Thanks for the responses all. My hope is to make the bike generally more rideable. I plan to replace the entire brake system with some old components I have laying around (old but better than what’s currently on the bike) — levers (eliminate the “safety handles”), cables, and the calipers/pads. But that rear caliper is problematic. Besides the cable routing, it’s actuates from the bottom. I don’t think a regular caliper will work when attached to the mount on the seat stays. That’s why I’m investigating a mount that would clamp to the seat tube.

Dan

sweeks

This x100! Many bicycle (and motorcycle) riders are taught, wrongly, that use of the front brake will pitch them over the bars.
-
I also endorse having the rider's dominant hand operate the front brake. All my bikes are set up with the front brake on the right (like a motorcycle).