Imagine the neighbours watching him through the window, "yeah Bob hes doing it again, riding up and down his garden skidding on his bike"

My ABS is called "the brakes aren't strong enough to lock up" and it's never given me a problem

"DIY" and "braking" are a precarious combination

As an auto mechanic, I finally felt fairly intelligent watching one of your videoes.

Why even in commercial devices the brake is released so significantly? The best choice would be a PID control to release slightly the brake to get the best possible deceleration according to tire friction, the deceleration would appear as constant (the PID loopback can be done thousand times a second).

I thought this was going to be a video of you 3D printing your own bike out of ABS

Great item to have in our weekender horse trailer!

This guy just ruined his backyard to teach us stuff. Respect.

This reminds me of a problem I faced trying to tune my brother's turbo Miata. We were trying to get the boost to hold a steady 10psi, but the controller was extremely finnicky, sometimes it'd overshoot to 14psi (hitting 'boost cut' where the ECU cuts fuel to save the engine from damage) or it would wander around 7psi. It was using a PID loop with a few tables and miscellaneous values to help prevent excessive lag or overshoot. The output from the controller was a PWM signal, 0-100%. After many frustrated tuning sessions, we finally found the problem. The controller was using the entire 0-100% output range, but the valve was fully closed below 70%, and fully open above 80%. All we had to do was "clamp" the output between 70 and 80, and it immediately started behaving normally. I feel like this clamping could have been used on your setup so it doesn't have to spend any time with the rope slack or so taught that it takes a moment to get the wheel unlocked again, if that makes any sense. I know these projects are usually one-off, but I think the response time of the system could be improved massively with a bit of tweaking to the software ;)

16:03 nice demonstration of abs giving you back control over the bike, balance and steering wise!

love it. I was stocked about the ABS on bikes, but maybee its still a nieche. Wow you did great work, fantastic!

Impressive that you were able to make something so simple and useful so complex and dangerous

This was fascinating to watch. The biggest improvement to motorbikes over the last 20 years has been in brakes, and I've often wondered how difficult it would be to create a retrofit kit to fit to older bikes that are still more than fast enough, but stop like a grayhound on a polished floor. One of those things that seems conceptually simple, but evidently complex in practice.

Well done mate! It really shows how hard is to replicate such easy to understand mechanisms. The first brake release mechanisms looked way cooler though ;-)

Someday you should also go through the programming aspect of these projects. Would be really interesting.

Electronic brake lever instead, have the electronics pull the brake cable directly depending on both the signal from the lever and wheelslip, you can even have different response times dependent on the signal from the brake, for example a lot od slip od allowed when pulled slightly, less allowed when fully pulled

"Maybe third time's the charm?" - unnamed ABS manufacturer

My abs is called "dont pull the lever all the way" and it works perfectly fine

You could put a wheel on the rope to change the response time mechanically. The rope needs to coil up on a small shaft requiring a longer linear throw, put a cam on it

the image at 3:46 with the entirely destroyed high current device is hilarious!

Physics is the greatest teacher of brake control on a mountain bike. Crash enough times and you'll figure out what you're doing wrong to fix it. Ideally, you'll be a one trial learner.

Your data should also allow you to calculate the friction of the surface from the first lock. You can then use this to predict the maximum safe breaking force and release the break to the ideal position. You'd just need to adjust the break pressure curve to allow the wheel to speed up again before clamping to the ideal pressure.

Way back when some kids bikes and adult comfort biles had a small spring in the brake elbow. Supposidly to prevent them from flipping over the bars, but it came at a cost of stopping power.

This man is a genius, some company should snap him up

16:51 i think he broke his leg

Tom, how about using a solenoid for the actuation? The response times would be very quick

nice, extremely complex and quite expensive solution for a problem we never had.

Skid and deal with it. Easy and more fun that way!

Superb job man, I'm greatly impressed with the amount of work that went into this one! Looking forward to the next project. :)

Love this kind of experiments, it takes a lot of time though, but research is worth it.

You're one smart cookie. I wouldn't have the patience.

I have that hot air station. It actually works really well.

Glad you ditched the first prototype, as you were running into the prpblem with this being a cable based abs braking system. When you look at a cars abs system, it uses hydraulic brakes and a very expensive abs pump to quickly and precisely pump individual brake circuits. You want the fastest possible mechanism controlling the pulse and release part, like a solenoid or high end RC servo. These slow stepper motors arent cutting

This is just fantastic. This video had me thinking about all sorts of things including why the ABS judders your wheels in an emergency braking situation.

On the mitsubishi starion the abs system is single channel and uses an accelerometer that measures lateral acceleration of the rear of the vehicle. It assumes if you exceed a certain lateral acceleration you're spinning and cuts brake pressure to the rear wheels.

Love what your doing.

This was far more interesting and technical than I first expected. Loved it! From a control systems engineer.

Very cool work! Perhaps a solenoid or other linear actuator would have better mechanical response time than the motor. Very good points about real-world applications too

I could see tom doing a MTB trail series one day

You can buy little force limiters for bike brake cables. Much smaller and simpler and doesn't require electricity

Hi Tom. I see that the motor turns around 180° or so, in and out to allow or disallow you to pull back on the brake lever. It looks binary, either it's on or off.. My question is.. Why don't you program the motor to turn slower on the way back and also not turn all the way back. It would reduce your delay. Thanks for your great video. Very inspiring.

Dude, you have one of the best hobbies ever! I wish I could come up with stuff like that by just tinkering around.

Cars do not use the wheel speed sensors to calculate the vehicle speed. The wheel speed sensors are for the abs. The vehicle speed is monitored through the vehicle speed sensor. Usually located in the transmission somewhere.

My antilock breaking on my motorcycle also ties the the breaking system of the two wheels together so if you apply pressure to on one lever the brakes are applied to both wheels

Tom your topics for videos are extraordinarily excellent. I am studying automotive engineering and the actual ABS works in a manner very close to what you were trying to achieve. Of course the hardware response time there is ridiculously high. But the theory remains the same. Enjoyed the video. I might just try to make my own abs bike someday. Preferably hydraulic. Also difficult to achieve higher response in cable operated brakes as they have longer travels. Hydraulics on the other hand have negligible travel.

Rather than having an ABS system that releases when it senses a locked wheel, would it work to make them completely fly-by-wire where the brake lever is just an input to the computer to indicate percentage of braking force? At 100%, the computer would only apply the maximum force that would still keep the braking of the wheel within the ideal slip ratio portion of the graph. So, instead of trying to modulate the pressure after it's locked, only enough braking force would be applied to maximize deceleration without the lock up.

you could also get the right tires for the riding conditions and imporve breakdstance

I just had an idea for solving the mechanical issue: Compressed air. It would probably only work with rim brakes, but basically, you shoot a little jet of compressed air through a hole in the brake shoe, temporarily lifting the shoe off the rim on a cushion of air. You could modulated the braking much more quickly just using an electronically controlled valve. Of course you'd have to have a small tank on board, but it would probably weigh less than that servo and its battery.

I wish you'd show controls without abs so we can see how much the abs improved braking distance

You could add a value for brake force and combine it with wheel speed to sample the break force right before the wheel skids, so the abs tries its best to avoid locking

To make a big difference you'd need to pre-load or stiffen the front fork too.

Cool project for commuting snow and ice.(fun of sliding wears off after a while) though it should have a fun mode (abs off)

After watching this again, I think the system could benefit greatly by having a force sensor mounted to log tension along the brake cable or hydraulic pressure in the brakes. I'm thinking that a logged force could be used to find a target for the stepper motor during slip events. My thinking is that once the abs activates, the swinging between stopped and rolling can be reduced. Might not be able to prevent the wheel locking the first time, but maybe could prevent the wheel from locking a second time.

i've had to emergency break a few times on my bike and i've skidded on ice a few times too but i've been biking daily for 4 years

This deserve 30 million views.

I think the rope is adding to delayed response because it acts like a spring and making the sevo travel extra distance

Wet grass? In England? Where did you find it? 😂😂

1:17 I cracked up when I saw that

good effort, looks like it works like my motorbike

Also, you won't go over the handle-bars if you just make the front brake slightly weaker that the rear brake. Works a treat. Sometimes the best solution requires nothing but practice and an Allen wrench.

Long before ABS, as a professional emergency services driver (fire) we were taught cadence braking; essentially manually operated ABS. I used that when driving my own car pre-abs and do the same with the front brake on both motorcycle and bicycle. It is an acquired skill but still very effective. It works best on hydraulic cycle brakes but I have also found that the front disc is so easily contaminated with road muck that it effectively turns itself into ABS by alternately slipping and locking but it is very noisy! I used to clean my front disc and pads very regularly but found it locked up on gravel far too easily so I left it alone. It works!!!! It's noisy but very effective (self) cadence braking. No need for expensive ABS as long as you can stand the noise plus the noise itself turns you into a very careful breaker; effectively a verbal cadence braking warning. It works for me and has done for many years. I'm 71 years of age and still riding 100+ miles per week safely. 😀

try using a gearbox and a brushless or brushed motor, with some math you'll find that you don't need a very powerful motor so you won't need to spend too much if you calculate right the gear reductions. you can cut the cogs with the cnc cheers!

Tom, have you ever considered making Eddy Current brakes for your bike? An Halbach Array of Nd/Fe/B magnets could replace the brake pads… and when pulled close to the spinning aluminum wheel rim.. you’ll get an effective non-contact brake… perhaps a thin film of PTFE sheet could cover the braking surface to allow “close contact” with no wear…

Put a piston in line with hydraulic breaks via a tee and push the piston in and out rapidly using an eccentric.

I did use a bicycle to go to work after 10 years of driving abs-enabled motorbikes. I did end up doing 2 stoppies during emergency breaking, one of which did send my flying over the bars. that's the price for getting used to ABS.

Are you sure the motorbike uses an optical sensor for the wheel speed? I've only ever seen vehicles using hall effect sensors, since the optical sensors would be subject to dirt and grime blocking the light emitter or detector. I've been looking forward to the next video, so glad it came out! Another fine video presentation. Nicely done!

Realistically on a bike it would be much more efficient to just gain the skills to not lock up the wheel, but this is just super cool

For a very slippery test surface, try dry sand on one year old dry asphalt on downhill. If you can get ABS to work on that, it will be good.

It probably need a PID controller to prevent oscillations of breaking force.

Next time would be good if you walked through the code on the next one of your videos like this. Can you do traction/ ESP on a remote control car??

Wau un mini laboratorio de ingenieria , primer mundo .

If you increase the step motor shaft size by 3 times (adding some sort of sheave) you will increase the response at least 2 times.

While mounting the stepper motor like you did is probably the easiest way to do it, I sort of wish that you had mounted it closer to the actual break instead. Also, perhaps it would be possible to attach something onto to the breaking wire. I'm thinking a small clamp that you could attach the stepper motor lever to. Your code is doing its job, but there's a lot of mechanical delays in your design. Since you're using a rope, applying tension to it requires a lot of time, and the stepper motor has to rotate a lot to apply that tension. I know that you're on a budget, but a high torque servo might serve this purpose better than a stepper motor. The horn of the servo would then be attached to the clamp. I think that you'd drastically reduce the mechanical delay this way, and you'd see a breaking action closer resembling that of a car. Apart from that, this concept and execution is probably your most interesting project yet, and that's saying something! Cheers mate.

So using the same knowledge you could create a traction control system for an electric bike like mine. I have a hub motor in my front wheel. If I'm going up a slippery hill and the front wheel loses traction while under power I may go down. If you could sample the speed of both wheels and cut power to the motor when the front wheel is going faster than the back wheel it would prevent some crashes and only require some code and the speed sensors.

You want a system that will use the motor to drop out a part of a tensioner with a cam. The pulsing will periodically add length to the cable, making the calipers let go. You need rigid linkage and the shortest distance between the abs and the caliper. Work with the force needed to lock your brakes, not push your hand up.

ABS actually stands 'antiblockiersystem' as it was German engineers that first brought the idea to a production motor car. Of course the English translation also fits the abbreviation and has taken over

You could use a servo controlled pressure unloading cylinder ,just put it in line with the caliper and move it in and out with a servo....

Hey Tom, it's quite impossible for a commercial motorbike to use an optical sensor for wheel speed, that must be an inductive sensor. Keep it up!

"Don't ride in the snow" is the only ABS system I can afford. this is cool though.

I've got a simple solutionish for skidding. Put a bigger grippier tyre upfront like a Minion DHF, you won't be skipping you'll just stop. The anti over the bars system might be appreciated then

My abs work most of the time, it’s called full suspension and it’s saved me a couple of times from going over the handle bars.

As soon as the wheel speed drops below the vehicle speed, fire reverse thrusters!

On a vehicle it requires a computer, in other words an ECM. the ECM measures the speed of the vehicle though the cruise control system. and also measures the wheelspin though wheel sensors. this information is sent to the ECM. and the ECM works out the variables and sends a signal to a hydraulic control unit. that is usually near the master cylinder. there are two reasons for this. one is so the pressure from the master cylinder is not interrupted. causing a pulsing sensation at the brake pedal. and the second is the ECM is sending a signal to the hydraulic control unit in milliseconds. which supplies the correct pressure to each of the four wheels as needed. most all automobile ABS systems require an ECM for the ABS systems to operate properly.

My ABS is "stop pressing the brakes when it locks and press the brakes again, repeat that until the bike stops" It works fine, faster than your mecanism in the video, and it saved me from many crashes. Pd: Sorry if i wrote something bad, I'm still practicing my english.

My bike has rim brakes, and it stops instantly if I squeeze the brakes all the way, at any speed. So, in that case, this system would prevent unintentional front flips.

Couldn't you use the delta of the velocity to determine where the deceleration is heading, then slowly let off the breaks until the deceleration returns to a safe range? This would make the breaking system more fluid rather than jarring.

Add a speed sensor to the back wheel and program for speed differential between front and back wheels.

making a hydraulic abs system using solenoids would be fun. you could make the high pressure go to a reserve tank when it kicks on then have it switch back to pressure and so on

I was getting concerned when half way through the video you hadn't mentioned accelerometers yet.... You were just trolling us though!

bro this guy got so much in his head

Bosch actually makes ABS for e-bikes, mainly intended for S-Pedelecs.

The abs has saved many a life in the commercial driving industry, but your real best bet without them is "stab braking" press hard, when it starts locking, let go, and repeat. Does the same as an abs but manually instead of automatically

I was waiting for a proper comparison of break time/distance with and without the "ABS" !

15:00 How about using an arm from the actuator to brake handle? It seems that the rope hack added so much stretching that it causes extra lag to the system. Another way would be to use actuator to move *pivot point* of the brake handle instead of moving the handle itself. With adequate movement of the pivot point, the same handle pressure can result in different hydraulic pressure. For example replacing the brake handle pivot bolt with a part that has off-center middle section it could move the handle pivot point a lot with only 180 degree rotation from the actuator (you obviously cannot ever get more than 180 degree range from actuator with this setup, note that you could also get faster on/off cycle with running actuator full speed in one direction).

also after the first break you can take up the slack on the motor and reduce the time to break

You should consider DIY frictionless brakes!! They already exist in concept, just isn’t used on bikes.

Spray some wd40 on the brakes then they wont lock 🤣🤣

FYI ABS is preferable on all road surface types (dry asphalt, wet asphalt and ice), but not on fresh, uncompacted snow (or sand) as when you are breaking snow is pilling up in front of the locked wheel and is providing additional friction. Here is an image I was shown at uni when discussing ABS, x axis is slip ration, y axis is tire coefficient of adhesion, A, B, C and D are surface types (dry asphalt, wet asphalt, fresh snow and ice) and green rectangles are slip ratio values ABS system tries to maintain: www.autoexpert.pl/img/15/rys_04-e51264c5d4b321edf9b6842ba2d8afc1.jpg

And here i am never having used the front brakes on my bike, i always used the back ones, no problem with braking and turning at the same time plus nice bike drifting action

I ride a lot in places were you would be prone to brake locking but the more experienced you are the better and the good thing about bikes is you feel what the bike is doing knowing how much brake to apply your fingers will do a much better job at it really, it comes natural to me you can hear it and feel it starting to lock up in a car or motorbike yeah its needed you don't feel the things as good in them since there heavier and more sturdy