Tell me if this is a genius idea or stupidity

[mickle]

I really like the cantilevers on my touring bike but they do run out of puff at the extreme of hill and loaded panniers. I've enjoyed fannying about with brazing additional rack eyes and water bottle bosses onto the frame with some success. And on the frame builder parts supplier's website they have a braze-on disc mount. I've built plenty of tandems with a third 'drag brake', usually located on the stoker's bars, so within easy reach of both captain and stoker. So the principle would be the same. Using a friction gear lever allows the brake to be activated and left on, like a drag anchor, just to take the speed off. On a tandem it can also function as a quick parking brake and a rudimentary (low security) parking lock.

I have a spare left side down tube shifter, I have a braze-on down tube shifter boss, I want new wheels for it anyway (front built around a SON dynamo hub that's been waiting patiently). So I could built a regular rim brake rim onto a disc hub. Second hand cable discs are cheap as chips and run the cable straight under the bottom bracket to a stop on the left chain stay.

And yes, I could just fit V-brakes. I have a full set including compatible drop-bar brake levers, but I don't want to lose my loverly Cane Creeks wot are on there now.

No I don't care if it adds weight. Have you seen my gut?

 

[JhnBssll]

My concern would be the additional loads put on a frame that wasn't designed for them. I suspect most frames are over engineered to the point that this won't matter but am not sure.

A constantly dragging disc will generate a lot of heat too.

Oh, and disc hubs are wider are they not?

I think it could be made to work, but needs some thought

 

[classic33]

I really like the cantilevers on my touring bike but they do run out of puff at the extreme of hill and loaded panniers. I've enjoyed fannying about with brazing additional rack eyes and water bottle bosses onto the frame with some success. And on the frame builder parts supplier's website they have a braze-on disc mount. I've built plenty of tandems with a third 'drag brake', usually located on the stoker's bars, so within easy reach of both captain and stoker. So the principle would be the same. Using a friction gear lever allows the brake to be activated and left on, like a drag anchor, just to take the speed off. On a tandem it can also function as a quick parking brake and a rudimentary (low security) parking lock.

I have a spare left side down tube shifter, I have a braze-on down tube shifter boss, I want new wheels for it anyway (front built around a SON dynamo hub that's been waiting patiently). So I could built a regular rim brake rim onto a disc hub. Second hand cable discs are cheap as chips and run the cable straight under the bottom bracket to a stop on the left chain stay.

And yes, I could just fit V-brakes. I have a full set including compatible drop-bar brake levers, but I don't want to lose my loverly Cane Creeks wot are on there now.

No I don't care if it adds weight. Have you seen my gut?

Yes.

What hand would you use to pull the third brake, or will it be part on once applied.

Pashley have the lever, pull to brake, on the top tube.

 

[davidphilips]

Sounds like a lot of work for little gain, I know you wont like my view but i would just go for V brakes.

 

[classic33]

Twin brake cables work on your planned setup?

 

[twentysix by twentyfive]

Just don't stop

 

[Soltydog]

It could catch on

 

[Old jon]

Great idea. My only wonder is why such astronomically expensive brakes, the Cane Creeks, do not work well enough in the first place.
Anyway, to throw another idea in there, why not try a retarder? A fluid or powder drive coupling would be possible, nah, this is becoming silly, who wants to throw engineering at slowing down?

 

[Levo-Lon]

Great idea. My only wonder is why such astronomically expensive brakes, the Cane Creeks, do not work well enough in the first place.
Anyway, to throw another idea in there, why not try a retarder? A fluid or powder drive coupling would be possible, nah, this is becoming silly, who wants to throw engineering at slowing down?

could go reverse thrusters, and extra thick Spokey Dokeys!!

 

[Old jon]

could go reverse thrusters, and extra thick Spokey Dokeys!!

If it was good enough for Campbell, fit a parachute!

 

[classic33]

If it was good enough for Campbell, fit a parachute!

Anything close behind could stop it working though.

 

[Hugh Manatee]

I would think heat would build up and fry the pads? Do drums dissipate heat better than discs in drag mode over a long time of being applied?
I have never used disks but, there has to be a reason others aren't doing it.

 

[froze]

Disk is an automatic no no due to the bike isn't built to take disk brakes. I'm not sure why you have issues with your canti's, I have cant's on my touring bike and I don't have any issues and all I have is vintage Dia Compe 960's. I had some issues when I first got the bike (I bought this bike used) with the brake being too stiff when applying, I dinked around with it for a while but couldn't figure it out so I took the bike in and they replaced the cables with newer slicker cables, lubed all the pivot points on the calipers and the levers (which had I did myself as well), replaced the yoke wires with either slightly longer or slight shorter wire, (I can't recall), and put on new Kool Stop Salmon pads, and adjusted them and the brakes work great now. Maybe try that stuff I mentioned if you haven't already.

I would say if all that stuff I mentioned hasn't worked then I would go with V brakes, must people seem to prefer them over Canti's. I have a bike with V brakes and I don't really care for them! But that makes me the odd duck out. Most of my issues with the V brake is my failure to understand how to adjust them, and they go out of adjustment much more frequently than Cant's especially after opening them up to get a wheel out then closing them once you put the wheel back on, something happens in that process that screws up the adjustment and then I have major issues trying to get them back into adjustment. Granted my V brakes are a mid level brake, but I simply don't see a big difference between the types.

 

[mickle]

Disk is an automatic no no due to the bike isn't built to take disk brakes. I'm not sure why you have issues with your canti's, I have cant's on my touring bike and I don't have any issues and all I have is vintage Dia Compe 960's. I had some issues when I first got the bike (I bought this bike used) with the brake being too stiff when applying, I dinked around with it for a while but couldn't figure it out so I took the bike in and they replaced the cables with newer slicker cables, lubed all the pivot points on the calipers and the levers (which had I did myself as well), replaced the yoke wires with either slightly longer or slight shorter wire, (I can't recall), and put on new Kool Stop Salmon pads, and adjusted them and the brakes work great now. Maybe try that stuff I mentioned if you haven't already.

I would say if all that stuff I mentioned hasn't worked then I would go with V brakes, must people seem to prefer them over Canti's. I have a bike with V brakes and I don't really care for them! But that makes me the odd duck out. Most of my issues with the V brake is my failure to understand how to adjust them, and they go out of adjustment much more frequently than Cant's especially after opening them up to get a wheel out then closing them once you put the wheel back on, something happens in that process that screws up the adjustment and then I have major issues trying to get them back into adjustment. Granted my V brakes are a mid level brake, but I simply don't see a big difference between the types.

This:

 

[froze]

Adapters are never as good as something that doesn't require adapters. In the case of forks, while you can use an adapter on a normal fork built for rim brakes realize to that a fork built for disk brakes has the entire length of the leg reinforced not just near the dropout at two attachment points which is all the adapter is going to do, after prolonged use of a disk brake with a fork that only has an adapter you increase the odds of the fork failing. The same is true for the rear stay. In my opinion using an adapter is mickey mouse. When a disk brake is applied the front fork will twist a bit toward the rotor side, on road bikes, due to making them as light as possible, even disk brake forks are seeing more twisting, this isn't as evident in more stout bikes but even with mountain bikes they still had to reinforce the forks; this twisting thing is also one of the reasons why there is more issues with spokes breaking.

https://www.velonews.com/2017/04/bikes-and-tech/technical-faq-disc-brake-wear-fork-twist_434593

https://janheine.wordpress.com/2018/07/12/myth-12-disc-brakes-work-better-than-rim-brakes/

Now having said all of that the original poster said the brakes were be put on a touring bike to which I must assume he tours on. Touring in developed countries having disk brakes is not an issue should you need parts, but in third world countries finding parts for a disk brake system could be a huge issue; a V brake, or cantilever brake is much more simpler and parts would be easier to track down. Also with disk brakes if you're rotor gets bent you'll probably be walking, and if you're in a third world nation when that happens you will be walking for quite a ways.