Wireless Hydraulic Braking Systems

[mattr]

It certainly shows that you haven't got a handle on the differences between the aero industry and the cycling industry.

[prendrefeu]

Every Airbus in the last twenty years has had fly by wire. So their flight controls use the same system. How does that fit your public liability model? If an Airbus control fails, 300 people die in a fiery crash. Guess that is a decent amount of liability.

First, airline industry ≠ cycling industry. You may want to read up on liabilities inherent in the airline industry, especially as a passenger vs. operator role.

Second, we're talking about braking here. So, "brake by wire" correct? https://en.wikipedia.org/wiki/Brake-by-wire
We'll get into the whole "wireless" thing in a second, but let's go to your notion of brake-by-wire (THAT IS THE TOPIC).
What happens when brake-by-wire (Electronic Braking System) fails on a vehicle? Oh guess what, there is an actual physical hydraulic line (air or liquid) creating brake actuation. In other words, manual backup. EBS exists so braking can be modulated in conjunction with the other electronic safety systems in place, such as ABS, EBC and others... you know things that do not, and will not, exist on a bicycle by the shear nature of difference between a 2-tonne vehicle and a ~6.8kg bicycle trying to come to stop.

Ok, so let's go back to the bike - this is Weight Weenies, a cycling forum, not an aviation forum or a car forum.
First let's start with the notion of electronic braking. The whole idea of electronic is to *not* have wires actuating a mechanism. So let's say electronic brakes come out... what will be the backup? Oh a physical wire? So you want a physical wire and electronic at the same time on the same brake caliper running the length from handlebars to caliper? Why bother with electronic then?

But, hey, we're talking wireless braking here right! I mean, yeah! Totally a great idea for saving weight and making the whole frame cleaner, right?
So wireless braking. Let's say it exists... then what happens when it fails? Where's the manual backup? If you locate the entire piston/pressure on the brakes at the caliper are you expecting the operator to reach down towards the hub of a wheel (presumably moving at a fast enough speed, hence needing an emergency stop) and actuate the brake caliper (rim or disc) manually? Really?? Let's say it's a rim brake: the next time you're descending at a fast speed (or let's say riding flat at 30km/h with other people/riders/vehicles around) try taking your hands to your calipers and manually closing them against the rim. Let's see how you do with that.

But wait, there's more! What if the system itself is wireless, but we'll run a cable (hydraulic or mechanical) from brake lever to caliper as backup... that'll solve everything, right? right? .... what's the point of going wireless braking again?

Then there's the whole issue of weight. Running an electronic system (wireless or otherwise) on brakes will add weight on top of that backup line. So... why, again?

Getting back to the issue of weight, and coming from someone who has serious interest in the wireless shifting notion of eTap:
The weight penalty for going wireless shifting is 70g. The result, besides the eTap tech of shifting, is a cleaner looking frame/bike set up.
Another benefit is being able to switch out handlebars/levers quickly on a bike to set it up for someone new. But what you'll need to do for the brake cables is add one of these to each line (http://jtekengineering.com/other/cable-splitter/ as an example, they come from a few companies). The weight penalty is 4-5g each. So wireless with fit modality is roughly 80g penalty.

But what if we just went with a straight mechanical set up and ran two sets of cable splitters instead, both for shift and brake, and placed them closer to the handlebars for ease of setup change? 20g penalty.

[prendrefeu]

Follow up post on another reason why wireless braking (and possibly electronic braking) is unlikely to exist on a bicycle:

1. You're probably reading/writing to WW on an electronic device. Please tell me, honestly, that your device has *never* had any glitches, coding issues, or failures of any kind ever. I'll wait.

2. Force applied over a length of time is what braking is. You just don't pull a lever once, release, and the bike (or vehicle) comes to a stop. Mechanical pressure, whether actuated by a wire or by hydraulics, is applied over time continually until the user is satisfied with the goal of the operation (ie, how much they want to slow down or stop). If this task was given to an electronic device (aka slave), your slave is applying a continuous mechanical force over a length of time. Large vehicles have batteries/alternators that can power electronic devices continually without issue. A bicycle electronic system tries to keep the batteries small and low power. When you shift the slave moves in one quick motion and that's it. There is no continual exertion of effort (electronic power being used to operate the slave) over a length of time. Ever use a cordless drill? You can drain the battery quickly if you just drill continuously for a length of time, even more so when you're asking the motor to apply more force/torque in its drilling action. That's what will happen on a smaller scale when you're applying brakes frequently on any given ride, you'll drain the battery (wired or wireless) comparatively quickly to the shifting action. So what happens on a ride where you've drained the battery from braking? You may stop shifting, which is totally fine you won't get hurt... but that whole braking part... how will you come to a stop now?

[spookyload]

Every Airbus in the last twenty years has had fly by wire. So their flight controls use the same system. How does that fit your public liability model? If an Airbus control fails, 300 people die in a fiery crash. Guess that is a decent amount of liability.

First, airline industry ≠ cycling industry. You may want to read up on liabilities inherent in the airline industry, especially as a passenger vs. operator role.

Second, we're talking about braking here. So, "brake by wire" correct? https://en.wikipedia.org/wiki/Brake-by-wire
We'll get into the whole "wireless" thing in a second, but let's go to your notion of brake-by-wire (THAT IS THE TOPIC).
What happens when brake-by-wire (Electronic Braking System) fails on a vehicle? Oh guess what, there is an actual physical hydraulic line (air or liquid) creating brake actuation. In other words, manual backup. EBS exists so braking can be modulated in conjunction with the other electronic safety systems in place, such as ABS, EBC and others... you know things that do not, and will not, exist on a bicycle by the shear nature of difference between a 2-tonne vehicle and a ~6.8kg bicycle trying to come to stop.

Ok, so let's go back to the bike - this is Weight Weenies, a cycling forum, not an aviation forum or a car forum.
First let's start with the notion of electronic braking. The whole idea of electronic is to *not* have wires actuating a mechanism. So let's say electronic brakes come out... what will be the backup? Oh a physical wire? So you want a physical wire and electronic at the same time on the same brake caliper running the length from handlebars to caliper? Why bother with electronic then?

But, hey, we're talking wireless braking here right! I mean, yeah! Totally a great idea for saving weight and making the whole frame cleaner, right?
So wireless braking. Let's say it exists... then what happens when it fails? Where's the manual backup? If you locate the entire piston/pressure on the brakes at the caliper are you expecting the operator to reach down towards the hub of a wheel (presumably moving at a fast enough speed, hence needing an emergency stop) and actuate the brake caliper (rim or disc) manually? Really?? Let's say it's a rim brake: the next time you're descending at a fast speed (or let's say riding flat at 30km/h with other people/riders/vehicles around) try taking your hands to your calipers and manually closing them against the rim. Let's see how you do with that.

But wait, there's more! What if the system itself is wireless, but we'll run a cable (hydraulic or mechanical) from brake lever to caliper as backup... that'll solve everything, right? right? .... what's the point of going wireless braking again?

Then there's the whole issue of weight. Running an electronic system (wireless or otherwise) on brakes will add weight on top of that backup line. So... why, again?

Getting back to the issue of weight, and coming from someone who has serious interest in the wireless shifting notion of eTap:
The weight penalty for going wireless shifting is 70g. The result, besides the eTap tech of shifting, is a cleaner looking frame/bike set up.
Another benefit is being able to switch out handlebars/levers quickly on a bike to set it up for someone new. But what you'll need to do for the brake cables is add one of these to each line (http://jtekengineering.com/other/cable-splitter/ as an example, they come from a few companies). The weight penalty is 4-5g each. So wireless with fit modality is roughly 80g penalty.

But what if we just went with a straight mechanical set up and ran two sets of cable splitters instead, both for shift and brake, and placed them closer to the handlebars for ease of setup change? 20g penalty.

I started riding before you were likely born. When index shifting was talked about, there were naysayers everywhere saying that it was a fad. Ten years later, not only was it the standard, but on the brake levers. Next step was electronic shifting. That started about a decade ago. Not the standard yet, but getting very refined. Now we have SRAM wireless. Big actuators and batteries. It is out though. After a first release, things get refined. Now you come in with your assumptions that it will never happen. Sorry, but I have heard that song before. Went to the concert, have the tshirt. TRP is step one into the process with their mechanical hydraulic brakes. All it needs is the wireless actuator, which honestly isn't that big of a jump from what is being used on the derailleurs.

Yes, if a battery dies, you lose your brakes. What will you use as a backup? How about the other brake? Last time I checked, bikes have two of them. Much like etap, they will each have their own battery likely. So yes, if a unicorn jumps in front of you, both brakes could both dies at the same time.

[mattr]

Wireless shifting to wireless braking, hydraulic or electromechanical is a massive step. You may have been riding since before Kirkpatrick MacMillan got his first two wheeler. But unless there is a massive change in electronics tech, we are probably 20 years away from wireless braking.

[ergott]

TRP is step one into the process with their mechanical hydraulic brakes. All it needs is the wireless actuator, which honestly isn't that big of a jump from what is being used on the derailleurs. .

Except if you read all the posts above you would have caught the part that unlike shifting, braking requires tactile feedback in order to modulate them. I have both mechanical and electric shifting. I see the advantage of more consistent shifting in more challenging conditions (under load). There may be naysayers, but it is an advantage.

Now look up the weight of brake hose and hydraulic fluid for both the front and rear brake runs. Think about all the extra components involved on both the lever and brake caliper not to mention the sensors needed, the brain to control pressure and feedback to the hands. This isn't just a button telling the shifter to move one position. It's an actuator with no direct connection to the brake. It's pressure sensitive. Heck I challenge anyone to make this work even with wires. It's so far fetched in comparison to shifting it's not even funny. At least we had wired shifting for many years before wireless (speaking of working production in volume, not the crap like Mektronic that didn't last).

[Calnago]

+1 ^

[ergott]

Vehicles and planes may have braking systems that are "by wire", but have you looked at the ABS system in a car? It weighs more than some of the bikes posted here. That's just one system that would be required to prevent lockup.

[spookyload]

Vehicles and planes may have braking systems that are "by wire", but have you looked at the ABS system in a car? It weighs more than some of the bikes posted here. That's just one system that would be required to prevent lockup.

Maybe that is because you are slowing a 2000# car and not a 20# bike. Do you have ABS on your current disk brakes? How do you prevent your brakes from locking up? Modulating force isn't super challenging. Digital control pads for video games give varying levels of input force based on input, and do it with almost zero effort. In fact, they are also wireless and utilize constant input pressure while gaming. Two double A batteries last in a game controller for hundreds of hours of gaming.

[spookyload]

Wireless shifting to wireless braking, hydraulic or electromechanical is a massive step. You may have been riding since before Kirkpatrick MacMillan got his first two wheeler. But unless there is a massive change in electronics tech, we are probably 20 years away from wireless braking.

I agree, we are 10-20 years away. It does still involve merely a piston pushing a short distance. There isn't massive fluid and cable movement in the TRP brakes. What is left to improve on when wireless shifting gets sorted and standard though? The industry won't stop and say, "we are done creating and inventing".

[ergott]

You really can't compare the feedback from a video game controller to the feedback needed to stop a bike and rider doing 50mph on a descent.

You haven't even explained why you think hydraulic is even necessary since you need a servo motor to actuate the brake caliper anyway. As you say you aren't stopping a 2000# vehicle. An electric motor could easily apply enough force to the brakes with the right leverage. Why have a motor actuate a hydraulic piston and add even more complexity to the system? That's how wireless shifting works.

Next time you ride, take not of the hand pressure you apply to the brake levers and imagine the feedback motors required in the lever to simulate that. That's a lot more than a video game and your life depends on it. Ever brake enough on hilly terrain that your hands got tired? Make the touch lighter? No ABS to prevent lockup? Yes an ABS system would be smaller than a car but it still has to be robust enough to put someone's life in its hands. Then you need speed sensors on the wheels to monitor wheel rotational velocity. You also need a brain to put make it all work.

Also, do you really think a haptic feedback system can adequate translate the feel of the brakes in you hand? Once removed you absolutely need ABS since you hands can no longer feel the grip levels of the brakes/tires.

Since you continue to defend this idea why don't you give us all an idea of how it would all work?

This is what's needed to make it work. Now put that all in a bike.

https://en.wikipedia.org/wiki/Brake-by-wire

What about this?

Missing data compensation[edit]
In a by-wire car, some sensors are safety-critical components, and their failure will disrupt the vehicle function and endanger human lives. Two examples are the brake pedal sensors and the wheel speed sensors. The electronic control unit must always be informed of the driver’s intentions to brake or to stop the vehicle. Therefore, missing the pedal sensor data is a serious problem for functionality of the vehicle control system. Wheel speed data are also vital in a brake-by-wire system to avoid skidding. The design of a by-wire car should provide safeguards against missing some of the data samples provided by the safety-critical sensors. Popular solutions are to provide redundant sensors and to apply a fail-safe mechanism. In addition to a complete sensor loss, the electronic control unit may also suffer an intermittent (temporary) data loss. For example, sensor data can sometimes fail to reach the electronic control unit. This may happen due to a temporary problem with the sensor itself or with the data transmission path. It may also result from an instantaneous short circuit or disconnection, a communication network fault, or a sudden increase in noise. In such cases, for a safe operation, the system has to be compensated for missing data samples.

Oh yeah, you want to make two, separate systems for front and rear so you have redundancy?

[spookyload]

Oh yeah, you want to make two, separate systems for front and rear so you have redundancy?

Yes. Redundancy is a good thing when talking brakes. Just like the SRAM system for shifting which uses a battery in each derailleur (interchangeable BTW, and you can replace it on a ride if needed). The hardest part will be the force feedback in the brake levers. I would assume there would simply be a negative spring of some type. Be it mechanical spring or electromechanical. Have you ridden hydraulic disc brakes? They have very little force feedback if you are riding a high quality system. You get the brake lever feel from the rate with which you put the force on the disc/rim and decelerate. The amount of lever squeeze isn't drastic with a high quality system. When driving, how do you know how far to push your accelerator? Many new cars no longer have a cable attached to the fuel injector. It is a signal from the pedal through a BIU to the computer. Translating analog to binary isn't a new thing. You would be amazed how many devices in your life use them.

[prendrefeu]

Spookyload, you might be better off just driving a car. It requires little to no effort, I'm sure you'll be fine.

[ergott]

Have you ridden hydraulic disc brakes? They have very little force feedback if you are riding a high quality system.

In fact I just got off my bike with Shimano R785 Di2 and Ice Tech 160mm front/140mm rear. What makes it so good is the fact that I really do feel the grip level in the tires. Nothing to do with force feedback at all. I can modulate my rear brake just up to lockup much easier than any road caliper I've ever used including Dura Ace, Super Record, and Force 22.

If you have hydro or access to it, try that simple test. Brake with just the rear wheel and see how much better that system is. Now think of all the added noise of a remote system that would get in the way of that. And for what?

When I mention redundancy it's not just the batteries. You need redundancy in the sensors all around so there are no lost packets. Seriously, read my other post.

[spookyload]

Spookyload, you might be better off just driving a car. It requires little to no effort, I'm sure you'll be fine.

I am also not a person who says it will never happen. I promise you I will dredge this up in a few years when we are seeing early prototypes of what you are saying will never happen.