Wireless disk brakes

davidof

The technology exists already. Will it come to cycling ?

jgsi

and what is Plan B, shoes on the tarmac like the 1960s? (me when my rod brake snapped)

PhilipPirrip

It's been done. Last example I saw was 7-8 years ago.

Not only was the primary braking system more complex and weighty but as suggested you'd need a secondary failsafe system, say Bowden cables actuated by levers on the bars.

shortfall

Presumably it can be engineered to have the same fail safe as existing hydraulic and cable operated brakes? ie keeping the front and rear brakes separate?

First.Aspect

Shortfall wrote:

Presumably it can be engineered to have the same fail safe as existing hydraulic and cable operated brakes? ie keeping the front and rear brakes separate?

What problem would this idea be a solution to?

figbat

What advancement is this offering though? Wireless devices are usually created to free the device from a physical tether, to allow convenience of placement, installation and/or use. A brake caliper is always going to be in the same place relative to the lever and never more than a meter or so at that. I can just about see the benefit of wireless shifters in terms of clean installation but let's look at the requirements for brakes:

- a battery at the lever and at both calipers
- a transceiver at both ends
- a motor/solenoid/actuator at both calipers capable of high force generation.

And what of failure? If a e-shifter battery fails, you're stuck in one gear; you can still move but not optimally. If an e-brake battery fails... then what? No brake on that wheel; you're then relying on the remaining battery for ultimate safety. This is all assuming you can establish a 100% reliable connection between the devices. I'll also assume that the batteries and motors needed will weigh more than a length of cable inner and outer.

There are no cars doing this and they have had access to brake-by-wire for a while. Aircraft have had (largely) reliable electronic control systems for decades, yet they are all hard-wired (or the safety critical ones are anyway) with redundancy built in.

I'd also wonder at the feel and modulation you can generate in an electronic system, wireless or not. This may require the insertion of virtual feedback into the lever, meaning more actuators and power use.

Fay those reasons, ahm oot.

proto

@figbat, great post.

shortfall

First Aspect wrote:

Shortfall wrote:

Presumably it can be engineered to have the same fail safe as existing hydraulic and cable operated brakes? ie keeping the front and rear brakes separate?

What problem would this idea be a solution to?

Someone else posted wireless braking as a topic for discussion. My suggested solution to total failure of the system is only offered as a counter to those who were questioning their safety on the grounds that such a failure could occur. I offered the counter that mechanical and hydraulic braking systems are fail safe because front and rear braking are isolated from each other which is a solution that can also be achieved with an electronic system.

figbat

One difference though is that the chance of failure for a cable or hydraulic system is very low and has very few failure modes. For a wireless system the chance of failure is guaranteed if you exceed the shortest available battery life, plus there are numerous failure modes to choose from.

navrig2

Benefit - nil
Likelihood of failure - determined by operator user so high
Impact of failure - catastrophic

No thanks.

step83

Basically wireless would be way way to dangerous, what could be done is better internal routing so from levers into the bar and so on. Main problems there are going to be the actual cable/hosing. All possible in theory just be an absolute pig to work on.

pamplemoose

Step83 wrote:

Basically wireless would be way way to dangerous, what could be done is better internal routing so from levers into the bar and so on. Main problems there are going to be the actual cable/hosing. All possible in theory just be an absolute pig to work on.

This is one of the big advantages of hydraulic discs and electronic shifting for me. The inside of the bike can be spaghetti junction but it has zero bearing on performance.

zest28

Since people somehow forget to charge their electronic shifting once every few months (no idea how they do this), you are going to have people who forget to charge their batteries for their brakes.