icepick_trotsky 

Are there any dual-pivot calipers out there that can operate via bottom-pull? This is for a mixte frame, where the cable routing runs down the mixte stays then up the seat-stays, comme ça:



It looks like most older single-pivot brakes could be modified, but modern calipers thread the barrel adjuster directly into the upper arm. Any ideas? Worst comes to worst I'll just run a dual-pivot in front and update the pads on the rear caliper, but I'd rather update both.

degan

I'd be very surprised if any exist that can be switched. I don't think I've ever seen a dual pivot that didn't just have a threaded vertical hole where the cable stop would have to be to make it work.

icepick_trotsky 

I don't know why any bicycles were designed this way. Any sane person would have put the brake bridge on the middle set of stays -- straight shot and normal cable routing.

gugie 

+1 That long housing swoop is a pain in the rear and makes the brake less effective. A really bad brake setup is a J-frame/mixte with cantilevers on the chain stays, and a pulley dingus hanging off the seat binder bolt. Now you've got a big S shaped housing that generates almost no stopping power.

On the other hand, cantilevers on that middle set of stays can hit the riders heels. A good alternative is a V-brake. My daughter can lock up the rear wheel without much effort:

icepick_trotsky 

Neat frame, @gugie. What is it?

smontanaro 

Which is what the few modern mixtes I just checked out do. Is moving the rear brake to the middle stays an option?

miamijim

Remove the cable fixing bolt and thread in a barrel adjuster. Up top you'll need to rig up a pinch bolt.

noglider 

Some calipers allow this, and some don't. I disagree that it's a bad way to route a cable.

rhm

+1. Replace the cable fixing bolt with a barrel adjuster and its anchor:



Thread the cable through the existing barrel adjuster backwards, and fix the end with a cable knarp.

gugie 

This was my very first "upcycle" project. It started life as a Nishiki Olympic 12 mixte. Here's how I found it - notice that the picture is upside down - it was hanging in an open-air car port. Rear derailleur had been ripped off, hanger was bent, rear wheel taco'ed. I gave the guy $25 for it. Basically reused just the frame and stem. Build story here.

miamijim

Tektro 800a should work with a simple swap of the pinch bolt and adjuster.

The Golden Boy 

I know that routing the cables like that make it much easier for water to get into the housing, stay in the housing and cause problems

noglider 

Hmm, good point. That's why they stopped making front derailleurs with housings that went into bottom-pull type mechanisms.

Grand Bois

The reach of the 800A is much too long for his application.

nlerner

Hey, that's my wife's bike. What's it doing at your house?!

icepick_trotsky 

Not necessarily. I'm planning on moving from 27" to 700c, so they might work. I need to measure.

icepick_trotsky 

Used for cable routing demonstration only. Nice work!

Grand Bois

I tried running the cable up the seat tube to a clamp and then down to the brake. It works, but I don't like it. It looks goofy to me. It wasn't easy to find a cable clamp that fits a seat tube.

The bend at the top is pretty tight, but you can get away with that with lined cables.

non-fixie 

Subscribing, as I'm facing the same challenge with this Cornelo. I've looked at Sheldon's solution, but that's a little too crude for my taste.

nazcalines

Another way to do this is insert a noodle into the brake caliper's cable stop. This makes the cable bend much easier. I went this way instead of of using a knarp and reversing the cable stop.

miamijim

Good point.

Tektro 539 looks modifiable. Sunlite 420 as well.

Bicycle Addict

I have converted a few to top pull, where your last cable guide is start you loop there, then get a chrome down tube guide for the seat tube, voila done.
Less ability for water to get in, I compared the cable after a year to the old one from the lower routing and there is significant discolouration to the lower routed inner , and some rust starting to form when it was taken out, both cables were in use for the same period of time, so water is a factor in lower routing.
Just my 2c.

Jeff Wills

I modified a Shimano 105 caliper for a bottom-pull cable to work on a recumbent with a very crowded fork crown/headtube area. I think you can buy bottom-pull dual-pivot calipers from Bacchetta recumbents: Bacchetta Front Brake

JohnDThompson 

That's what I did with my daughter's FrankenSports: