Crazy idea? Brake by wire - not cable!

[Clancy]

Just saw the post on the Argonaut w/SRAM e-tap with hydraulic brakes.

Made me think of the simplicity of set-up except the hydros.

Which made me think.... possible one day to do break by wire as in new cars?

Or, Bluetooth breaking with hydraulic discs?

Imagine the ease of set-up

[batman1425]

Imagine the force of impact when the transmitter/receiver drop their pairing mid ride from interference or battery loss. I'm sure such systems could be made to be nearly as reliable as cable or hydro system, but the consequences are quite different from losing shifting performance. It will take quite the body of evidence to convince people that e-braking is as safe and "better" than the already very good cable and hydro systems.

[JWDR]

Originally Posted by batman1425

Imagine the force of impact when the transmitter/receiver drop their pairing mid ride from interference or battery loss. I'm sure such systems could be made to be nearly as reliable as cable or hydro system, but the consequences are quite different from losing shifting performance. It will take quite the body of evidence to convince people that e-braking is as safe and "better" than the already very good cable and hydro systems.

Safe enough for cars but not for bikes, got it.

[54ny77]

no thanks. call me a luddite.

[batman1425]

Originally Posted by JWDR

Safe enough for cars but not for bikes, got it.

Cars have a bit more liberty with respect to the size and weight of a safe and effective brake by wire system. Integrating that tech into a bicycle where weight and aero are major concern will vastly impact the viability of it in a bicycle application application.

Additionally, the current brake by wire applications in hybrid and electric vehicles frequently have mechanical/hydraulic backups in the event of a electronic system failure.

[mt2u77]

I'm amazed at how much faith is put in WiFi/Bluetooth reliability. Those devices operate in the ISM band, where there are literally no limits on radiated power and no requirements to play nice with bandwidth consumption. There are lots of legit industrial, scientific, and medical equipment that will blast any Bluetooth signal away for a half mile radius. Even without such interference, signal quality is unreliable and subject to a lot of buffering to keep things flowing.

As an engineer in the field, it will be a cold day in hell before I let Bluetooth control my brakes. A dedicated band, with enough redundancies designed in, and automotive level reliability standards, would be a slightly less cold day in hell-- but the bike market is way too small to merit that type of investment.

[Mark McM]

Originally Posted by Clancy

Just saw the post on the Argonaut w/SRAM e-tap with hydraulic brakes.

Made me think of the simplicity of set-up except the hydros.

Which made me think.... possible one day to do break by wire as in new cars?

Or, Bluetooth breaking with hydraulic discs?

Imagine the ease of set-up

Are the electronic braking systems in cars and trucks wireless, or do they use hard-wired connections?

For the cars and trucks, there is a significant amount of electric energy continuously available to operate the brakes. For a bicycle brake by wire system, what energy source do you propose?

[batman1425]

Originally Posted by Mark McM

Are the electronic braking systems in cars and trucks wireless, or do they use hard-wired connections?



For the cars and trucks, there is a significant amount of electric energy continuously available to operate the brakes. For a bicycle brake by wire system, what energy source do you propose?

Every one I have seen is hard wired.


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[Nooch]

Originally Posted by Mark McM

Are the electronic braking systems in cars and trucks wireless, or do they use hard-wired connections?

For the cars and trucks, there is a significant amount of electric energy continuously available to operate the brakes. For a bicycle brake by wire system, what energy source do you propose?

Next development, etap/di2/eps powered by dyno hubs...

[batman1425]

Originally Posted by Nooch

Next development, etap/di2/eps powered by dyno hubs...

That's one application where this might work, regenerative braking from a dynamo hub, but you would still have to supplement with a mechanical system of some kind.


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[54ny77]

This all sure makes cycling sound like fun.

[bicycletricycle]

I think that the rear brakes on formula one and some hypercars are fully electronic. They have gone this way so that the systems can integrate in the regen braking smoothly. Apparently it is really hard to get them to "feel" right.

I am not sure if they still have a physical hydraulic system, perhaps the "electronics" just actively manipulate the hydraulic pressure being created by the drivers foot.

I think brakes that don't work when your batteries run out seem silly. They would have to make them so that they locked up if any of the systems failed (like air brakes). That would be interesting

[Mark McM]

Originally Posted by bicycletricycle

I think brakes that don't work when your batteries run out seem silly. They would have to make them so that they locked up if any of the systems failed (like air brakes). That would be interesting

I don't think that idea would be safe at all - you don't want to be driving down the highway at high speed and suddenly having your brakes lock up.

Instead, this issue is more likely to be addressed by redundant systems - which even mechanical systems have. Current cars have to independent hydraulic systems (that work on diagonally located wheels), plus a cable operated emergency brake.

[bicycletricycle]

Air brakes on trucks auto lock when the system looses pressure, I think.

Originally Posted by Mark McM

I don't think that idea would be safe at all - you don't want to be driving down the highway at high speed and suddenly having your brakes lock up.

Instead, this issue is more likely to be addressed by redundant systems - which even mechanical systems have. Current cars have to independent hydraulic systems (that work on diagonally located wheels), plus a cable operated emergency brake.

[Mark McM]

Originally Posted by bicycletricycle

Air brakes on trucks auto lock when the system looses pressure, I think.

Only the parking brakes. The normal operating brakes use air pressure to apply the brakes (and won't work if pressure is lost).