Bicycles are the most efficient machines for moving a person around, and wireless drivetrains have been heralded as a way to make shifting more consistent and require less maintenance. [Blake Samson] wondered if the same could be true of wireless brakes.
Inspired by the controller for an RC car, [Blake] picked a 150 kg servo attached to a cable-actuated hydraulic disc caliper to apply the braking force. The servo, receiver, power stabilizer, and batteries were all mounted on a custom steel plate fabricated to mount under the caliper. [Blake] cut up an old set of mountain bike brake levers to reuse the handlebar mounts and then put the batteries, controller, and finger triggers on them.
Confident in his hacking skills, [Blake] then took the bike out on some trails to test the brakes. As a prototype, there were a few surprises along the way, like one of the triggers staying locked in the braking position, but they performed admirably enough that he’s mulling over a Mk. 2.
Bikes are one of our favorite hacking platforms. Be sure to checkout this dreamy cargo bike build, an awesome bike camper, or what can happen if your bike is dependent on the cloud to work.
Thanks to [FedX] on the Hackaday Discord for the tip!
Wireless shifter? Ok cool. Brakes? Absolutely not
All of the best safety equipment comes in wireless, like Wireless Anti-Static Wrist Straps!
And the Tiger-Repelling Stone! Even works without a battery!
Same Thing I was going to comment.
Are you aware most of the controls on jets work on similar principles, including the steering?
Triple-redundant though…
“you were so preoccupied with whether you could, you didn’t stop to think if you should.”
Bicycles have a long tradition of unnecessary changes but this might be the strangest one yet.
Works great – until the batteries fail.
Also, what does this actually do for you over a cable? There’s a sentence about it making shifting ‘more consistent and require less maintenance’ but I don’t recall my bikes ever requiring much maintenance in the first place and certainly a *wireless, battery-powered module* isn’t going to be less than occassionally spraying some lube on the cable ends.
I *guess* this could be the first step towards ‘abs for bikes’.
Electronic control of braking, coupled with dual-channel control of both wheels (along with the sensors) would allow you to get maximum braking capacity across a variety of surface conditions.
People who ride bikes way more with my can chime in if this is something desired.
Though ABS for bikes have been DIYed before by having a servo tug on the cable or lever. Allows still to keep the mechanical path intact for when the electric system fails.
https://hackaday.com/2019/02/17/anti-lock-brakes-for-bike-might-make-rides-a-little-safer/
There already is ABS for bikes, Bosch offers it on some of their eBikes.
My only question, when the battery goes dead, do the brakes default to always on or always off?
Neither option is really desirable, but there is a big difference in “undesirable by how much”.
IMO the correct model is the one brakes on large trucks have: springs with enough force to apply the brakes, then you use the electronics to release the brakes. That way it fails safe.
On the wireless side, you’d want an affirmative heartbeat from the handle, and if the receiver doesn’t get one every so often, it automatically brakes (probably gradually with a warning tone first).
If it sounds too complicated, it probably is. But anything else (unless you have backup mechanical actuation) isnjust a recipe for disaster.
The spring wont fail safe. It will send you flying over the handle bar.
The only fail safe is servo assisted mechanical brakes.
Brakes on truck/train are not really fail safe. They fails always in the same way: applied.
Which means that if you are on flat ground you will stop safely.
But in a steep decline, it means that you can also burn your brakes and fail catastrophically.
Lemme take a stab at that one. No.
Although I’m always interested in the implementation! I’m all for testing probably bad ideas as long as it’s not akin to solar roadways on a public street.
Who knows? Maybe it’ll meet some corner case perfectly.
Lolololollllllll. Lolz.
No no. Noooooo. No.
While I agree with most of the comments questioning the safety of a remote control breaking system, I don’t feel like the experimenting should cause so much concern. [Inhibit] mentioned corner-cases this design might be died for, and I agree: imagine a “brake-by-wire” system powered by an on-board generator (perhaps backed up by a manually actuated emergency brake for redundancy). Now imagine that system on your children’s (or disabled family member’s) bike, but with the addition of a wireless remote control to enable to the parent to override and apply the brakes. It might be a niche use, but could be helpful.
I don’t want my children to get used to remote disabling of their vehicles;)
Good point, I had a nasty bike crash when I was really young because I became afraid and couldn’t press the break. My father ran behind me to try to catch me up (we were downhill) but he wasn’t fast enough and what happened happened.
If he had a remote break, I might not have crashed!
You could also argue that it learned me a great lesson about what not to do if I didn’t want to crash…
Brakes, dammit. You don’t want to break your brakes.
There is an emergency break system for parents https://mystopy.de/ (only german, sorry) “stop” but it seems to work :-)
A simple cable from the handlebars to the wheel is lightweight and reliable.
Batteries and servos add weight and uncertainty.
Do not want.
They actually aren’t all that reliable in my experience. Sure, if you squeeze hard enough they’ll engage, but I for one think there’s too much flex in the system (at least in the mass-produced bikes) to feel fully comfortable relying on them in traffic. Is this the answer? Probably not, but I think innovating in this area is a must for the future of.
“Sure, if you squeeze hard enough they’ll engage”
That sounds pretty reliable to me… sounds also pretty easy to fix too. You can start with the adjustment screw on your break handle, which takes 5 seconds and doesn’t require any tools.
Manual hydraulic disk brakes are a thing, and they offer plenty of stopping power and good feedback through the handle.
Lighter than cable systems, too.
When they are sealed and working properly, they are amazing. I can lock both wheels with one finger on each brake lever if I am foolish enough to apply the moderate amount of force it requires.
I don’t know if they’re any lighter than cabled brakes, but hydraulic lines/calipers/levers can leak which affects braking performance. When they leak you get air bubbles in the line and then they become squishy and lose stopping power. If it happens to leak with the oil ending up on the rotor, it loses even more stopping power and becomes very noisy. Ask me how I know…
Intellectually, I think the remote-concept experimentation has merit: maybe leave a backup “emergency” cable connected.
With such an implementation, would one need to be concerned about space-weather, solar flares, and EMPs?
With a backup cable, what’s the point of having it also wireless?
Just make it wired only….
Wireless brakes are a bad idea all round.
Two likely use cases:
1) When you are already going to have an electrically-dependent braking system, such as computer-controlled 2-wheeled vehicle. I’m thinking autonomous vehicles, remote-control vehicles, and vehicles controlled by the user’s eyes or brainwaves (think disabled bicyclists).
2) When, for whatever reason, you want the primary breaking mechanism to be one that is already dependent on electricity (e.g. power-assisted brakes on an e-bike). In this situation, you will still need a non-electrically-dependent way to safely stop the vehicle in case of emergency.
For almost all bicycles whose existing braking system doesn’t already require electricity, the existing system is good enough and almost anything that adds a dependency on electricity won’t be worth doing except for certain use cases.
That said, hack on my friend, hack on.
Having tried full-hydraulic, cable-to-hydraulic, and full-mechanical bike disc brakes, the full-hydraulics give vastly more braking power for a given amount of lever force than the other two, so I’d think having the servo push on a hydraulic master cylinder going to a full-hydraulic caliper would be much more efficient. It should be easy enough to do just by modifying a hydraulic brake lever.
Of course this was done mainly as a joke, the only real advantage of a brake-by-wire (err, wireless?) system would be making some automated brake control systems possible, like ABS and descent control. On an MTB being able to run your rear brakes up to the limit of lockup automatically on a descent could be really handy. ABS with an anti-OTB system on the front brake could also be useful.
Oh. Hell. No.
I’ve limped out of losing a hydraulic line, snapping my spare cable, losing the front caliper bolts, pad retainers, pad material (in very mucky-crunchy conditions) but I can’t imagine enjoying the failure mode of control-less brakes. Yuck. DOT 4 and cables forever \m/
I’d rather drive a damn cybertruck than muck with my brakes. No, wait…I’d rather ride binary feeling Shimano brakes than drive a cybertruck.
This is a terrible, terrible idea. The added weight alone makes it ridiculous, but as others have pointed out it is also considerably less reliable on probably the most important function of a bicycle … that being the ability to stop. Some hacks are useless but cool. This isn’t one of them.
There was a curmudgeon dude named Jobst Brandt that was an engineer and wrote a lot on Usenet about all things bicycle. Even wrote a book called The Bicycle Wheel. Over the years he gave a lot of engineers level descriptions of the physics of bikes and bike design. A little gruff sometimes but hey.
Anyway he would have a field day with this. For one- the amount of brake lever force with a cable is plenty to easily lock a back wheel. Locking a back wheel is very controllable and as a child you learn to rip rad brodies and wear out tires at a record pace.
Later in life racing bicycles I learned that during edge of performance descents the back wheel stepping out a bit is recoverable too as long as you have road left to recover. If the front wheel slips even a little, down you go.
I’ve also, plenty of times, done maximum performance braking with front brake only and only realized the back wheel was off the ground an inch or two when i let off the brakes. It’s perfectly and fully controllable the entire time. I rarely use the back brake because it barely works and when you actually try to slow while racing it’s to SLOW down. The back wheel just locks.
Sorry that’s a long winded way of saying that normal boring reliable brakes are an entirely mature if not perfected technology much like the bicycle itself.
I live in Cambridge Massachusetts where bikes are driven through red lights a thousand times a minute.
Brakes? They done exist here.
If it were a BMW bike they would love this. Think about it for a minute, subscription based braking on bikes. You could charge a monthly sub just to use them. This idea is Genius and for everyone putting it down shame on you……….
This is already a thing in china, the brakes lock up when the rent expires, throwing you over the handlebars
http://www.youtube.com/watch?v=TCC13EyR79c
I have a even better business plan idea: charge per use. I would call it “HP Instant Break”, it starts at $.99 per month for up to 10 brakings!
A physicist, an engineer and a programmer were in a car driving over a steep alpine pass when the brakes failed…
Physicist suggests dumping excess weight;
Engineer suggests trying the handbrake;
Programmer suggests turning the car off and then on again to see if it fixes the problem.
You mean a Windows .NET programmer? The Linux guy wouldn’t think of that!
He would be too busy checking online for the correct systemd command for this time-critical situation…
oh come on, some bored teenager with a cantena is going to create a whole new episode
of “wacked out sports” with a few riders on this!
I can’t help thinking about “darwin award” and “kiss”.
I also can’t help to fantasize about this going main stream. Imagine a world where wireless brakes encounter directional radio jamming systems. The perfect way to create dangerous chaos at busy intersections. A nice plot for a serial killer movie: the target on its bike approaches a very busy downhill intersection and the killer deploys the jamming system making it all look like a silly accident, this movie could go on for hours.
Just a thought….
Not to burst his bubble, but they’re definitely not the “World’s first” wireless braking system:
https://newatlas.com/wireless-braking-for-bicycles/20150
Article from 2011…
I can’t help noticing that on both versions (which are referred to as wireless) have a lot of wires hanging out of it.
I also couldn’t help noticing that in the linked article was written “the system should offer 99.999999999997 percent reliability – that means it would fail three times out of a trillion braking attempts” I seriously wonder how they determined that. as there is only the first prototype and no serious statistical real world testing. Now it could have been that they tested it in the real world and noticed that on their initial testing scheme of 1 trillion test brakes, it failed the first 3 times. But seriously, how many charges does the battery hold, how much brake actions can you do one one charge. I’m pretty sure that the battery is dead before a million is reached, I consider that a pretty big failure. Mentioning fancy computer algorithms intended for airplanes and factories has no serious overlap with the real world of bikes, which are being thrown around all day in all sorts of weather without serious maintenance or care. A number of 99.999999999997 percent reliability is pure bogus if you ask me. What also doesn’t help is that the system is designed by computer scientists at Germany’s Saarland University, what do they need to focus on bikes, 99.999999999999999999999999999999999999999999999999999999999999999999999998% of the bikes function pretty perfect without software.
I mean this version could be totally wireless had he spent a load more time tidying the project up, somehow integrating the entire thing into one package so to speak (no battery wires showing, built-in charging port etc… But for a prototype, I would say this is wireless.
I tested enough automotive ECU’s to know that brakes sit at the top of the safety relevance pyramid.
I wouldn’t ride such a bike above speeds at which I could stop it without the brakes.
Almost everyone who is saying “hell no” here is overlooking the fact that bikes have two sets of brakes and you mostly use the front one. I could see using a wireless system where both the back brake and the shifting was wireless IF it weighed less and gave me the same ability to feather brake. I’d always want the front brake to be cable/hydraulic actuated but cutting out the cable between the handlebar and the back brakes could have some advantage both for maintenance and safety. Hack on dude!
Unfortunately a very misguided idea on many levels.
1) There’s no failsafe
2) Servos are not designed to be operated in a stalled condition, which this application would be.
3) water ingress is highly likely to be an issue.
4) Excess weight
Hell. No. We’re (and I speak for us since you spoke for us) not overlooking “the two brake situation”, some of us ride technical trails, or, you know, in cities where needing to stop in a predictable fashion can be very advantageous.
Have fun, try it! I’ve ridden with 0, 1, and 2 brakes and I most enjoy rides that start and end with 2 _working units_. Bikes are not only fair weather tools and environmental abuse is not so kind to critical systems that will eventually meet rocks or metal with significant momentum.
You pointed out the hacker spirit, which is rad! I love it also. Keep hacking, there might be a good application for this learning. But to be an old hacker you need to know a poor application when you see one. Or just don’t piss on the third rail.
Better use: use the servo to rotate a playing card into the spokes – provides that pleasing retro noise from childhood plus VERY mild braking.
Sing it with me “Nothing’s going to stop us now…” (Thank you Jefferson Starship)
Nice to play around. At least in the EU practically impossible to implement commercially due to EN 62745:2017+A11:2020
Leaving aside all the safety and reliability concerns; as person who loves machines I would miss the feedback cables provide to my levers from the brakes, very important when modulating 2 brakes with minimal traction.
Also possibly the worst application for wireless, something less than 24 inches away normally operated by a lever 🤦🏼♂️.
Blake, I appreciate your ambition to do a cool thing. Congratulations on making it onto Hackaday! I prefer cable, even over hydraulic. It’s the thought that counts though. You had an idea, and you made it happen! Surely you can use it for something, if not braking. KEEP BUILDING!
Yeah, don’t take a break!
now lets put torque-control (VESC-like) ESC and a brushless motor instead of potentiometer servo, ring of magnets on disk-break and HALL sensor for an ABS-like speed sensor and finally implement ABS for an MTB. So many “fly-over the bars” will be avoided
is fly over the bars common from braking authority? i have biked a lot and i have only actually taken a header from more severe control problems, such as my feet slipping off the pedal while accelerating hard, or the front wheel going in a ditch. i’ve done emergency stoppies a few times and fwiw i have always landed right from them.
basically if you nail the front brakes and have the traction for it then you have a moment of lifting the rear wheel off the ground but still with good control authority. so long as you feather your brakes during that moment (or come to a stop with the wheel in the air), it isn’t that bad.
but i’ve also learned how to manage a limited amount of front wheel sliding so maybe i’m just unusually lucky i don’t know?
it just seems like something you worry about because it’s such an obvious problem, but in practice doesn’t the worry serve the function of preventing people from actually getting bitten by front brakes?
Next up, IoT brakes where your bike has to be in constant contact with a server so you can request braking via an iPhone app as long as your subscription to the braking service is paid up and the company hasn’t gone bust or invested it all in crapto and been rug pulled.
The internet seems to believe it was Woody Guthrie who said:
“Any fool can make something complicated. It takes a genius to make it simple.”
That would suggest the obverse is also true and this article does nothing to disprove that.
The only way I can see this being useful is maybe like a dead man’s switch. So when you lock it and walk away the breaks lock on. But imagine passing a source of rf interference whilst riding at speed and suddenly having it unexpectedly apply the breaks of it’s own accord.
Personally I think I’d rather stick with a good old cable actuated break.
Brakes, brakes, brakes, brakes, brakes, brakes, brakes, brakes, brakes, brakes, brakes, brakes, brakes, brakes, brakes, brakes, brakes, brakes, brakes, brakes, brakes, brakes.
Dammit.
I feel better now.
*brakes
It’s even in the article, and the title.
Also, *its.
Wonderful article!
There was a similar effort at a german university around 12 years ago:
https://cordis.europa.eu/article/id/33925-scientists-develop-wireless-bicycle-brake-
I don’t understand. What was wonderful about it?
I think he meant Wunderbar
In the immortal words of Homer Simpson “Eeeeehrrrmm Noooooooo.”
Somehow, I feel that wireless brakes will get me on the Darwin Awards list.
obviously i agree with the people saying “no” to this hack but…
looking at the design, i think it’s simply wrong…a servo controls position, not tension. so it seems like it would be very hard to feather at all through a servo. add in the lack of feedback and i think it would be nearly impossible.
but that’s a prediction, and while i’m sitting here in my armchair making predictions, i’m thinking “gee wouldn’t it be nice to *actually know* what it feels like”. and this intrepid hacker got to experience it first hand. so just for the experience, i figure it’s a neat hack…buy the ticket take the ride. you won’t find out what it feels like without hacking!
So planes flying with millions of people every day, have wireless and fly-by-wire controls without direct connection from the controls, but people would not put it on their bikes interesting logic.
such an enormous number of differences. first, so far as i know no airliner uses wireless electrical signalling for control surfaces. their big innovation was switching from tension wires or long hydraulic runs to electrical wires, but they still have wires. also, they have a lot of redundancy…sometimes a critical signal is reduced to bits and bytes on a wire but that wire is duplicated through other routes on the plane, and so are the control servos.
but the biggest difference is just the motivation. airliners are so big that long runs of mechanical connections become a liability on their own. and they are so big that the pilot doesn’t have the strength to move the control surfaces without significant powered assistance. and they have so much autopilot that it’s already been decided to involve a computer in the control path. and they have such a wide flight envelope that they often desire the computer to be involved even when it’s not on auto-pilot. to make the airplane more flyable even though the control surfaces act in a radically different way at 150 knots than 450 knots.
the bike has no autopilot — ABS would be the next incremental step over the status quo. and the brakes don’t require any more strength than the pilot can provide. and the 2 feet of brake cable between the left brake lever and the front brake caliper isn’t a technical challenge to manufacture or maintain and it doesn’t represent a significant source of failures. and there isn’t much redundancy, and we’re not inclined to add more redundancy in response to new introduced failure points. there’s no pressure to just plain old make the bike twice as big that makes it worthwhile to add more control overhead.
anyways i just think it’s interesting how the much different needs lead to much different solutions
This moment when you remember, that you forgot to charge your brakes !
As long as there is a mechanical fallback, go for it. 100% for innovation, even if it looks “risky” sometimes.