Oh, Boy! A homemade, high-speed flywheel rotating just beneath my groin!

Achievement Unlocked: Tom Stanton has advanced into the Iron Age

Tip for the flywheel: Because the mass at the outside of the flywheel has more rotational inertia you would have better performance using a thin central disk, and welding or bolting thick rings on both sides to make the cross section an I beam. For the same volume/mass you would have a much higher rotational energy saved up at the same RPM. :)

The sound coming from these gears made me appreciate how well made bicycles are

Amazing, I love a bike build/project and this was spot on

Lube. Lube those gears. You’re losing a tremendous amount of energy in friction on those chunky cogs.

You need a 19lbs plate and a transmission to a higher gear ratio to get more value out of the discharge. You'll see a dramatic change in how aggressive the takeoff will be. A sort of tapping of the clutch can get you up to a pretty high speed. I'd recommend doing the transmission from the other side of the bike. A sort of 2chainz bike if you will.

Going down a hill you could get the RPMs up really high, then use it to help with going up the hill on the other side.

There's a HUGE problem with flywheels, as a large mass rotating at high speed introduces unpredictable changes in behavior of the entire system, when turning left or right.

Hey, that sounds like an amazing Sack Shredder

I think a viable use-case for a flywheel is on a trike. You pedal at a constant speed more or less, not exhaustingly hard (< 200W), including while stopped. Then you have hopefully cached up enough energy while sitting at traffic lights to have decent accelleration without needing a lot of Li batteries that are too expensive for their service life. A flywheel applied this way should last forever. Probably there is a known name for this concept.

I found myself nodding in understanding multiple times through this video lmao you're so good at explaining these things without having to dumb down the concepts

Get the flywheel up to high speed when going down hill, then use that energy to assist when climbing the next hill.

0.086mm error when drilling holes, 2cm error when hanging pictures on the wall ;-) priorities!

Cool concept! What if you used a torsion spring instead of a flywheel? Might be lighter, plus there would be no time limit on stored energy. Could add some kind of ratcheting mechanism so that it can’t propel the bike backwards while tensioning the spring, and then probably another handle would be needed to engage some kind of reversing gear and release the spring tension 🤷‍♀️

Thanks Tom. I'm glad to have found your channel. As a wannabe engineer, it's fun to live vicariously. This project brings to mind an idea I had long ago when I learned about angular momentum: it would be cool to design a bike with weights that ran along the spokes that you could adjust radially to affect your speed. Cheers!

"However, you can't charge and discharge this batterys not nearly as fast as this flywheel..." Sounds like a new Super Capacitor Project :-)

"from breaking loose at high rpm" - he means: "from slicing me in half"

Your videos are truly inspiring... You try and learn. Truly a role model for young people venturing into engineering

A bolt on kit could probably be made or combined with an existing engine based design to help improve efficiency. It is quite impressive that you've managed this with simple machining tolerances limiting you. You should try a design with the flywheel weighted towards its edges (i.e. thicker towards the edge or with a heavier metal bracketed around the circumference of the flywheel!

I can already imagine V2 of this bike: Tom pedaling next to you at a red light. You look at him weird. Then green light > clutch engage > zoom away. You in dust.

UKpostsr: talking about raid- Literally every soul in this planet: *SKIP 10S SKIP 10S SKIP10S**

My full respect for all your experimenting and doing such things.

I had an idea like that before, but have never been disciplined enough to invent things. My main idea was for the gyroscopy to help with balance at red lights, but releasing the power for a head start is pretty clever too.

Why not use a circular spring to store rotational energy while braking, so you can store the energy for a large amount of time without the flywheel slowing down? That'll come with the added advantage that you're not adding as much mass to the bike, you only need engage the mechanism while braking, and it won't be as noisy.

has the added bonus of sounding like a TIE fighter as you ride by your friends.

Super cool! Not sure what settings you have on your fusion 360 CAM setup but if you haven’t already, adding a finish pass after the rough cutouts for all the CNC router parts would likely improve the circularity of the bores and overall accuracy. Having an aluminum sub plate vs MDF would also help with the overall rigidity and improve surface finishes. Keep it up!

I like it. I have a downhill mountain bike. Imagine this concept on the downhiller. You brake all the time. Could use the flywheel to boost off jumps or when it’s time for a short pedal between downhills. I think you got something here if you refined this. Although I wonder about gyroscopic forces on the bike and how it will effect turning and stability.

Needs a sprag clutch on the flywheel in series with the clutch, so that when decelerating it automatically disengages when the flywheel exceeds the bikes speed.

Tom, you need 2 gears for the fly-wheel, a high gear-ratio for slowing down and a low-gear-ratio for speeding up, think of this this way when equilibrium is reached you want fly wheel speed high relative to wheel speed, but when speeding up you want the wheel speed to be high relative to fly wheel, anything inbetween can "solved" with your clutch.

wow... I love the thinking and work that went into it.

I saw this video a couple years ago and I always wondered if it would work better if you put a heavier flywheel in the rear wheel between the spokes and use a clutch to engage it. Spin it up with the pedals once you’re moving and then engage the clutch when it gets up to speed to either accelerate or cruise.

Must be nerve wracking knowing there's a heavy metal disc rotating at thousands of rpm right below your nuts.

That floppy chain kills me

You could try building it inside the rear bike Hub in between the spokes. You could also then put some of these aero plastic covers over on top of the spokes, making it basically invisible and also more aero dynamic and the flywheel wouldnt have to fight against as much air as it had to before. Im thinking of a mechanism somewhat similar to drum brakes they used to have inside of bike hubs

Flywheel effect applied with electromagnetic force on the flywheel and on the bicycle rear wheel, and a dynamo to power the electromagnetic field should work. So you're pedaling is directly into a dynamo and the flywheel, and the energy from that goes into the electromagnetic force propelling the bike. Can use a clutch to disengage the dynamo.

That’s great. Now I know why bikes never use flywheels.

Adds heavy disc to capture energy when stopping. Increases mass of bike so it takes more energy to accelerate again.

This is awesome! I'd like to see the difference in amount of time it takes to accelerate a certain distance with and without the flywheel being charged while accelerating.

Hi Tom, how about a clock spring (mainspring) placed within the rear wheel spoke area which gets wound by braking ,stores energy , which gets utilized when the brake is released.

UK Guy: I found people selling steel discs on eBay. US Guy: targets. You bought targets.

When he began to say "because steel", there was a small stop, so I was honestly expecting for second for the sentence to continue with "because steel is heavier that feathers"

My personal opinion is that you are onto something. Even thought it may not have worked out exactly as you had hoped, mad props to the effort that went into this.

It would be some what dangerous...but I wonder if there is a way you could store the energy in a strong spring instead. The way garage doors do. Springs are the best at storing mechanical energy. Because they are essentially like mechanical batteries. It would make an excellent braking system for sure, because it would brake with progressively more force the longer its engaged. And if it had a locking gear system, that only released upon command, you could store that extra boost as long as you needed. It wouldn't be quite as dangerous, if the spring could be stored some how within the tubes of the bike frame itself, so they couldn't shoot out, if snapped. Its not something I could build, because I lack the tool and experience. But based upon what you made, it seems entirely possible. In essence turning your bike into a wind up toy. Except it would wind itself up while braking with a clutch. Seems like you have most of what you need for the idea done. If you modify the flywheel to wind up wire rope instead, conceal some springs safely in the frame or in a sealed add on container, and run the wire rope with welded pulleys. This concept would be much more effective. Another benefit is that you could utilize the boost whenever you'd like, from a dead stop to get you going, to help you up hard inclines, during the middle of you peddling when you're tired, or even while you are peddling at your top speed for like an rpm boost.

This seems like it would be useful on hills, gathering momentum in the flywheel downhill to help uphill

I'm actually curious as to how effective the flywheel could be in maintaining the speed while coasting rather than using the energy to take off from a start. Just a thought.

I work in electronics and my solution would obviously be regen braking. The idea is ridiculously simple: you have three half-bridges powered by the battery that provide voltage to each phase of the motor. The higher the voltage, the higher the RPM. If you intentionally reduce the motor voltage below what its RPM should dictate, then the motor will charge the battery. The only additional component needed would be a dual stage brake lever. Pull the brake slightly and you send a signal to the controller to start regen braking. Pull hard and the lever pushes the master cylinder as well so you have a combination of regen and friction braking for a shorter emergency stopping distance and a failsafe if the battery craps out.

This was so cool to watch , obviously could be improved in many ways but damn its fun to watch this type of prototyping kinda stuff. Well bloody done !

While I'm sure it's perfectly safe, I'm not entirely sold on the fast spinning metal positioned under my nuts.

Now you need to design a CVT to transfer more more energy into the flywheel instead of wasting the remainder of the momentum in brake pad heat. Also, with a different spoke design you might be able to place a 26" flywheel concentric in the wheel. The larger size could store more energy at lower rotational speed.

There was a tractor that had those matched sloping spiral ramps on it, like the thing you built. It needed repair as the ramp steps got beat down over tyme. P.t.o. reverser it was called. Im sure you have heard this already, but methinks you need a machinist to make your dreams come true. Wonderful show, really. Well made

This is a righteous design totally saving those valuable energies my dude

That's a nice idea. I quite like it. I imagine spinning the flywheel when going down a hill and then using it to help accelerate up the following hill again when I'm losing speed.

Oh great, it's RAID season again. They must be losing money.

I have an idea, the gear ratio that is used to charge the fly wheel will affect the force of braking, it may spin the fly wheel even faster, and that mean the bike will accelerate much faster (if the fly have enough torque) and reach a higher speed. Also if we use a gearbox which contains 2 speed (low and high), i think it will much more affective than that. Those are just some thoughts, may i be stupid.

A great concept and design. I had a similar idea but had thought it best to drive the flywheel from the crank and engage the drive sprocket to the flywheel. Of course, the flywheel would require more mass.

I think I would LOVE this arrangement on particularly hilly rides. I'd use gravity on the downhills to spin-up the flywheel then release that energy for a boost at the base of the hill and the start of the next climb.

"Speaking of raid-" *SKIP*

With the flywheel spinning at a stop, how long were you able to balance before putting a foot down?

I've had this dream for over a decade! thank you for doing it!

For more efficiency, I think you need two different gears, one for decelerating, and one for accelerating.

That's surprisingly efficient! But I do think you should still try building a CVT some time because it would really benefit this and a lot of your other projects, you might be able to recover more like 70% of the speed. Since you have access to a CNC machine, I don't think it would be as complicated to build as you might think.

I can see this being part of an enduro bike. When going down the hill, with gravity the energy from the rpm of the wheels is stored at the bottom of the hill, and when you start to go up, you can release it and get quite a boost to get up to speed

Love the bravery of this guy to test out an experimental, self-modified, imperfect prototype bike while not wearing any safety gear whatsoever. Engineers scare me.

I mean, there's no point in spinning it up while pedaling. The entire idea is to recover the energy that would otherwise be wasted as heat by braking with conventional friction brakes. Instead, you're doing nearly 7 times as much work to store that energy as you would have used just to accelerate from the stop that much by pedaling, due to the 15% efficiency (a loss that isn't present in the pedal-only method). What this _could_ potentially be used for is for storing energy while coasting downhill while maintaining speed, to then be used to continue to maintain speed on the way back up the next hill... but I think you'd need a real CVT for that. And a much better flywheel that isn't quite such a rickety, terrifying mess, and that can preferably go to _much_ higher RPM to store a whole lot more energy. However, I think by the time you do all of that, just adding a regenerative braking system with a capacitor and either a large enough electric motor to reuse the energy, or a smaller motor driving a flywheel electronically, would be much simpler. The electronic systems would basically behave like a CVT but with a lot fewer wear parts and a lot less noise. Also, just FYI, tire weights are designed to go on the inner surface of rims, so centrifugal force helps keep them _on._ That adhesive is in no way designed to hold them against pure shear force like that! Finally, all that noise is also wasted energy. Not a significant quantity for the quick stop-go runs you were doing, but waiting at a stoplight or a crosswalk could see a rather large chunk of your hard-earned kinetic energy sapped away by parasitic friction effects.

Thank you! Interesting video, now, after years, I kind of understend what the KERS system is actually doing when Ferrari introduced it to their F1 cars.

love to see you combine the magnets from the gearless magnet bike idea, with this some how

Tom have you done a video where you describe what kind of CNC cutter you are using with aluminum? Would you buy the same cnc system again?

Just like the old friction, toy cars we had in the sixties………still a good idea if it works full scale.

This would be a great concept for those who live in a neighborhood full of hills where you would need to go up and down frequently. The flywheel could be used instead of the brakes when going downhill (for the most part), then the flywheel could be used to (somewhat) assist with going uphill, thus making the climb a touch easier.

This explained SO much to me! Thnx!

I could see myself charging up the wheel going down hills and using it sparingly whenever

Sounds like you were losing an insane amount of energy from vibration and friction

This is awesome. You just got a subscriber, sir.. I can't wait to watch the ebike one tomorrow

Really like the flywheel concept knowing that it can add some weight. i also like the air bike, some years ago I considered using the bike frame itself for the air can.

An infinite CVT would enable you to minimize energy lost to friction within the clutch system. It would be REALLY awesome to see you design a compact CVT. You would also be able to transfer more energy into the flywheel than just matching your half initial velocity magnitude of the bike.

So when your normal bike is not giving you enough exercise just add a flywheel to it.

Cool. i did this too in 2003. My flywheel was a 26" mtb wheel with 6 guage copper wire wrapped around to evenly distribute weight. I removed the top tube and installed a split top tube for the wheel to slip thru to fit it on a mtb. I left the cassette hub with 7 speeds on it so I could really get it up to speed. So Yes I had a pair of grip shifters and an extra thumb shifter on the bars.I did not use a clutch, though my friend wanted me to do that to do "burn outs". The end result was it was too much of a workout. It did seem to help getting up a hill after running down a hill.

50 years back my dad built a bike with a flywheel mounted in the same orientation as the wheels but as you rode the back wheel spun the flywheel in the opposite direction via a chain and cogs. This bike was used as a party trick as it was nigh on impossible to ride.

This would probably only make sense when going up and down hills, as you wouldn't want to go down hill too fast, but would want some assistance going up

It requires quite a lot of energy to get going for standstill. KERS is more useful for storing energy from slowing down before going into a corner and then using that energy to recover momentum (or building up speed) as you are coming out of a corner.

Appreciated man 👍🏻 keep going this kind of creative things!

Flywheel Ultimate Cycling Kinetic Energy Recovery System Got your acronym sorted

I would love to see how this might work in a situation where you have a downhill to uphill road segment, and see how the flywheel might assist and help propel you up the hill… by like engaging the flywheel to build up energy on the downhill segment and release that on uphill

I would really like to see this when going down a large hill.

I make small engines and windmills for a hobby. I use compressed air as well as steam to spin up a flywheel, which doubles as a generator rotor, having permanent magnets press fit about its circumference and passing through a pickup coil. Doing this allows me to take advantage of steam when it's overpressured as well as when it's not. It works pretty good. I manufacture the steam from a tracking, concentrating solar mirror I designed and can generate free electricity on clear, sunny days.

Cool ! And what do you think of the idea of a spiral spring that would be tensioned during descents and released during ascents in order to climb more easily?

I would imagine that the applications of this would be better in a more hilly area, to help with climbing using the declines to charge the fly wheel

Raid: Shadow Legends follows me like a curse. Will I ever escape it?

The amount of extra work your putting into the pedaling to only hardly save work starting again really shows me why I won't need a flywheel on my bike.

If the flywheel could capture enough energy to accelerate you back to the original speed, you’d have a perpetual motion machine.

this would be perfect in a descent followed by an ascent, you store the energy when descending then release it on the ascent

Haven’t heard your conclusions but mine would go something like, “In this video we learned there’s no such thing as a free lunch.”

Brilliant 👏 👏 👏. Not easy to do things like this at home. I wonder if something like this could be done with a thick coiled spring like that in a clock .

Wow, very interesting. I am quite fascinated by energy harvesting by regenerative braking system. You mentioned that it collects back 15%. How much would it be actually if you consider added weight by the harvesting system that requires more energy for the initial acceleration?

Braver man than me to have a home-made steel disc spinning in-between my legs near my tackle.

Our boy Stanton: "I heard you liked spinning wheels, so I put a spinning wheel between your spinning wheels so your wheels can make the wheel spin when they spin!"

If that flywheel was perfectly balanced, and it had better bearings, that thing could probably spin pretty fast. Having a perfectly balanced flywheel on a vehicle is pretty important.

Could you not make it a dual clutch mechanism where you keep the conventional clutch assembly but use add one to either side and also add 2 separate ratcheting/centripetal clutches (one for each direction) then connect each conventional clutch to its own handle. One to brake one to accelerate. Or is there something I am overlooking?

When he said that the bike parts are cheap and easy availeble I really felt that.