Disc vs. Caliper continued - How about both?

[smead]

Originally Posted by Mark McM

Drag brakes aren't controlled like normal brakes. Instead of being momentarilly applied, released and modulated like standard brakes, they are more typically applied and left on at a constant drag level.

If you take a look at the first photo, you'll see what looks like a bar-end shifter at the end of the stoker's handlebar. But instead of being attached to a derailleur, the lever's cable is attached to the drag brake. On a downhill, the stoker will set the drag brake control setting to a fixed position and leave it there (instead of shifting to a specific gear, the lever with "shift" to a specific drag force). For speed modulation, the tandem captain adds additional brake with his standard levers as necessary.

As I mentioned earlier, this was a common system when the "shift" lever controls a special drum brake, in conjunction with rim brakes controlled by standard brake levers. These drum brakes were designed for continuous heat dissipation, just for this purpose. But rim brakes usually aren't designed for as much heat dissipation as those drum brakes work, so I don't know that this is a wise set-up.

Yeah, I know, but it would be so absurd to drag a rim brake that I just assumed the stoker would use it like a normal brake to scrub off speed here and there. Goofy setup either way.

[thirdgenbird]

Originally Posted by flying

Aside from the cool tandem....I have often wondered why the industry didn't go this route anyway

Think about how many cars even now have disc front & drum rear

Same for many motorcycles.

So for bicycles the industry maybe missed a level of profit...That being introduce disc capable forks & let road rider keep a rear rim brake.

Save them having to buy a whole new frame set to try disc
They could even offer a complete upgrade kit to fit most bikes etc

Then again they probably feared the obvious.... that folks would half try disc & say forget it

I assume the driving factor was feedback and feel.

Cars have linked braking systems and motorcycles use one hand brake and one foot brake. On a bicycle, you control each brake independently with the same style inputs. Matching travel ratios and lever feedback is easy if both brakes are the same type.

I am a bit surprised we don’t see more mullet setups in the aftermarket. Disc front and rim rear has some practical applications with old frames.