1175 How To Make A Dual Freewheel Differential For A Paper Trike 

Ingenious use of those freewheel assemblies! I love it!

Brilliant, thanks Rob. For those rummaging through scrap yards.. The spin-on clusters / cassettes are typically found on old bikes. Newer bikes have the free-wheel built into the hub.

Hi Rob. I played with this idea to go onto a recumbent delta trike based on a design sold by a family design team here in Canada. Their build projects (and there did quite a few) used square tubing for many fabricated parts. I came up with another 'version' of the differential you describe there after getting my hands on two large "finger ratchet wrenches" - these are like a conventional square-drive socket ratchet wrench, but with no handle. They're meant to be used in tight spaces. I got a pair that took 1/2" drive sockets (I later revised the design to use 1" square drive socket wrenches) and after more than the usual messing around trying to do for 5 cents what any fool can do for $5, I had a differential real axle that worked quite well. At the time, I was planning to use 48-spoke 27" rimes for my rear wheels. A machinist in Australia very kindly made up a set of 48-spoke hubs, and (miracle of miracles) I found some high quality 48-spoke rims for sale by a British maker. At the time (2010-ish), the pair of rims cost just over CAD$110, plus 6 pounds 95p for postage. They arrived in three days - some kind of record in anyone's book. Since we have ice and snow about 8 months of the year, one over-riding concern was/is cold-weather operation. I also hoped to have an "electric assist" system that could be activated for steep hills, etc. The rear end - axles, bearings, ratchet-based freewheel/differential(s) plus the necessary frame were pretty much complete by 2013, along with about 2/3 of the rest of the frame and front end. Then someone stole the whole works, plus all of my welding gear. In the same period, I became permanently disabled and so was retired from engineering (cold-weather methanol fuels among other things) and there were two deaths in the family, all in a very short amount of time. My disability required quite a bit of revision to the basic recumbent delta trike, but I did get some plans drawn up. However, not being able to work (and therefore being without income), plus dealing with two separate family wills pretty much put the whole project on hold. Since then, because of an accident and new factors arising from disability, plans will be changing yet again. It was suggested to me to consider using motorcycle wheels for the rear pair, rather than bicycle wheels and rims. This idea has some merit, but make a home-brew differential more difficult. Reason #1 was simply tire and wheel strength. The most frequent points of failure on bicycles and tricycles here are flat tires and damaged rims. Of people who commute using a bike or trike, 44% report at least one flat tire every 10 days. The other main reason for considering motorcycle wheels was better traction and (by using Aluminum) a lighter overall rear assembly. If an electric assist was still a possibility, weight is a major problem. Being poor (where I once was not) has really made this proposition difficult and unlikely. There are very few "free" or inexpensive sources of modern batteries to be had. The cost of material and welding equipment for at least part of the frame being changed from steel to aluminum tubing is a big obstacle to this idea as well. Road conditions here are not ideal much of the year, but I mention that proposal in the interest of completeness. It seems unlikely and unaffordable at this stage. Anyhow, I love your design for this simple implementation of a working differential, and I have seen actual examples on hand-built trikes locally. Cheers from northwest Canada.

I made both types of trikes back in my youth (1970's) It was a baptism of fire when I figured out about the issues of not having a differential :O

This man has helped me so very much. I'm making a Delta trike camper and this made it a peace of cake, thank you!

That was cunning. I love lateral thought.

For most users, 2 wheel drive trikes are overcomplicated. I built a semi recumbent delta trike with one wheel drive over 12 years ago and have done more than 25,000km on it. I have only ever had traction problems in mud and snow. Making it single wheel drive made loads of problems go away and gave a load of advantages. To move the drive from the centreline to the left wheel, I used a technique from Atomic Zombie. This adds a separate drive shaft half way between the pedals and rear wheel, with one chain from the crank to this shaft and another chain from the shaft to the driven rear wheel. The shaft is made from a bicycle wheel hub, split it in half and a tube welded between the 2 halves. A 10mm steel rod is easily threaded with the standard bike axle threads and the old bearings reused. If a rear wheel hub is used, rear derailleur gears can be used in the centre shaft, as well as the rear wheel, doing away with the dreadful front derailleurs, which are always unreliable. By using this technique, I have 6 front gears, 7 rear gears, giving a total of 42 gears!!! Other advantages are an open area between the rear wheels for a cargo box, shorter chains (recumbents often have very long chains) and everything is easy to access for maintenance. I am thinking of adding electric augmentation on the currently undriven rear wheel by simply replacing the wheel with one with a hub motor.

What a lovely bloke! Pleasure to learn from you sir!

Thanks for the update on the wheel ideas 😊 out standing buddy 😄 thanks again.

Awesome explanation & walk through demonstration 👍

Wow now that was some really good info!!

That welder has come in really handy. I use mine more than I thought I would. I need to get a large spring clamp out the other day and one blob of weld and a pair of grips and away it came lol

Hi Rob. That is so clever! And so simple.

Great video. I’ve been thinking about building something similar for my grandsons. I was stuck on the rear axle. Pretty sure they are not ready for a drift trike lol This video was as if I had ordered a sandwich and you were telling me what is on it Thank you, kind sir

Simply brilliant!

Brilliant, thanks for sharing the information 👍

That's genius

Awesome! So straightforward. Thank you Thank you Thank you!

Remarkable idea indeed!!!

Absolutely clever!!

Thank you for the great information and I'm hoping to be able to follow you, and make this as well Andrea, Jasper and George the Pigeon. XxX

Ive thought about doing this but the only way I can figure out braking would be a disc brake beside each wheel with a brake cable splitter to y out one cable into two so that both rear brakes would be operated by one brake lever. This is better than a normal differential because it's still a positive traction rear end. Using hydraulic brake line would be better than a cable to split and it would be a more equal pressure to each rear caliper.

Great Work Earthling Bless Up :)

Un maestro... No hablo inglés y lo endendí igual. Muy Genioooooo

VERY CLEVER HOW YOU MADE THAT LEFT DRIVE WORK AROUND, HOWEVER THEY ALREADY MAKE A LEFT HAND THREAD FREEWHEEL THAT COST THE SAME AS A RIGHT HAND OF ABOUT $10-$15 EACH. LET ME KNOW IF YOU WOULD LIKE A LINK TO THEM.

Just brilliant!

Good idea but I think the brake won't work the axle will stop spinning but the wheels will continue to rotate

Having driven a rear wheel drive road car with a locked differential I can tell you unsurprisingly it did not like roundabouts. On a comedy note you appear to have a disc brake on the rear axle kart style, I suspect that you have spotted the issue with that. Keep up the good work, some great ideas.

Great explanation.

I thought about it, but i couldn't solve the "wrong" turning direction. Well played, mate. By the way, how did you solve the breaking problem?

Awesome project... I do have a slightly silly question. Is the brake attached to the axle that the cog is attached to? Would this not lead to the freewheel engaging when you brake, meaning no brakes on the back?

I've been thinking about delta drive arrangements also. My idea is to have 2 wheels mounted on non driven axle. The wheels on ratchet drive are attached with one wheel reversed so both drive cogs are facing inboard. You then drive each wheel from a common drive shaft. This should allow one wheel to travel faster than the other around corners, but drive both wheels when going straight.

That's beautiful. Using a tool to modify the hub, it looks fairly simple I wonder does it need two brake discs to keep the vehicle from pulling to one side, when you apply the brake?

Awesome idea

Thanknyou for this relaxt video..best wishes from the middle of the Netherlands

Thanks sir greatly explained

Thanks Rob, i want to make a trike, and have been thinking about drive arrangement.

this is amazing. I'm working on my alt ev also at the moment

Great way of making a freewheel very inventive thinking only one question when you apply the disc brake it will stop the axel but surely the freewheels will just carry on so the brake will only work if the trike is going backwards or am I missing something

pretty good idea, am gonna try it...one day

I'm building a tadpole 3wheeler using two 16in rear bike wheels. The have freewheel coaster brake hubs. The wheels are still driven by the chain and pedal cranks, but I cut the cranks to just stubs and are connecting the two with a shaft. So the shaft spins the cranks that drives both wheels. I thought this will work like a differential, but it isn't the same, as when the shaft is powered, both wheels must spin at the same speed, but if you stop powering them they will freewheel and can turn at different speeds. So you can't power through a turn like a true differential. Just thought someone might like to know about this setup, will have this project on my channel soon.

Great work 👏 👍 👌

Excellent! Thanks!!!

as a MadMax fan I just love this video

Damn, you're a smart cookie. Need more like you in this world. About the only topic you haven't covered is DIY fuel for a home made missile / rocket, lol. 🤣

Brilliant!!!

Thanks Rob.

Thank you! Thank you! Thank you!

This looks like a nice application for unidirectional roller clutches. They're simpler to make than a freewheel and they don't click. Sometimes they are called "one way bearings". I never would have thought to use a freewheel as a differential though! :-)

Brilliant idea. Although I do not totally get how it works, I am sure I will do at some point. The diff problem has always been a biggy when it comes to 2 wheels at the back. I have tried a cart with one powered wheel, but even that system works best when the powered wheel is on the outside of the corner.

I used sprag clutches to do exactly the same thing. These are like bearings that engage in one direction and free wheel in the other. Also, you can use 2 on each wheel in place of the bearings. I got the sprag cluches off old printers.

that is miracle !

Said 'freewheel' so many times! Seems like a cool design, putting 2 freewheel things on one side to reverse direction doesn't make sense intuitively, but it seemed to work i guess.

The brake on the axle is not going to work now!

Not to nitpick, but with that arrangement, it looks like the brake would be ineffective (unless you were rolling backward).

Up to the welding I was entertaining hope for my cambered rear wheels with independent axles.

Good stuff 👏

If you appky braking to the axle you wont stop, because the wheels will free wheel, you need to brake from the rim or outer sleeve of the hubs, or come up with another solution.

ı really wanted to see this tested in real life conditions it would be very cool

Wish I had seen this video earlier for one of project. I have been struggling with angle grinder grbx.

oh my god, you sir are a genious! that's so simple that I was not even thinking about doing this kind of solution :D but one question though, the threads on the wheels are in a different order once they are flipped, so one wheel tightens as it spins, the other one will untighten, or am I missing something? also, will the brake be usable on the shaft once it's all mounted up?

hi, first comment; I came with that solution days ago and marvel myself because this arrangement doesn't have the problem of the xhausting power through the fasttest wheel. So the power alway goes with the slower wheel which have the less weight in a corner. In case the inner driven wheel drift in a corner, then the other wheel automaticly engage as magic. Isn't that awesome?. The only problem is that in a turn always will be just a driven wheel. I think your brake is doing nothing, it had to be attached directly to the wheels or you will need a two way freewheel. Then, also you'll be able to pedal backwards. Cheers, and thanks for be so caring with your audience.

cool, now someone attach a 6" Rhombic drive Stirling engine to that axal with a paint on heater end, & vacuum flask cold end in the right orientation, + mostly magnetic Stirling cycled copper coiled heads+ magnets+ caps to feed the encased heater, call it good as a base low energy input amplifying device to be optimised ^_~

That’s cool, a couple more steps and you could make an independent rear suspension for a quad.

Brilliant ...

This is essentially exactly how a detroit locker works.

So, unless Ive got this wrong, the drive goes to the inner (slower) wheel not the outer wheel? Which is the wrong way round for a trike because the inner weel will lift off the floor in a curve and all traction will be lost. You always need traction to the outer wheel.

3:58. You don’t use a punch to remove those, you use a chain spanner

I have noted you have some physical aspects of you design presented backwards. The inner wheels is the drive wheel in turns with your design.

How do you get all that to pass through the frame holes ???

For the next video you can show us the crash when the brakes don’t work.

Modern high performance motorcycles often have two discs for braking, there is a valve body that the lines attach to, so that the master cylinder activated applies equal pressure to both slave cylinders at the same time. I forget what the part is called, in an automobile it is called a metering valve, I think. Its mounted to the frame rail of the auto chassis, near the main cross member that holds up the transmission. It's not a serviceable part.

Genius.

Pardon my ignorance here but I’m looking into making a 2 stroke converted trike from a run of the mill, inexpensive 7speed trike. I’ve been trying to figure out how to fix the rear sprocket (the drive cog that comes with the conversion kit) to the axle without f’in anything up. I might have to get rid of the rear brakes but I’m not worried about that. I haven’t gotten the bike itself yet but was wondering if the newer bikes (getting it brand new) are two freewheels on the back and not a fixed axle so I wouldn’t have to worry too much about slight turns at speed. I won’t be going very fast anyway but just wondering if the motor being fixed to the middle of the axle will mess that up. Maybe a stupid thing to ask I hope some of that made sense. But thanks to videos like this my understanding is steadily growing!!

06:15: How did you preserved the oil in the freewheel as long as you heated it?

A question regarding the "no reverse" statement (6:32): As far as I know, "normal" (two wheeled, geared) bicycles also don't reverse, and pushing them backwards engages the pedals and rotates them back. Obviously there's a reason, or you wouldn't have mentioned it, so why did you? Thanks

Genius

It's basically, the angular momentum, in forward directions cannot be slower than that of the axle. But since it its a freewheel, it can alway be faster. So the wheel wit less angular momentum, will always receive 100% of power.

The inner wheel on a corner will be the driver, meaning there will be either a slowdown through the pedal system or an acceleration of the trike. We may also see that if the velocity through the corner is sufficient there will be an overturning moment about the outer wheel which causes sufficient decrease in traction of the inner wheel that the outer wheel drives while the inner wheel spins faster! I await the practical evaluation with great interest!

The nice shiny brake disk is now useless! no brakes on the rear axle, BACK to the drawing board!

Or just install one way bearings in the bike hub (they only rotate one way)

Nice and good

Hello Robert what axel are you using for this project please

You would assume that cars could use a similar free wheel and lose the geared differential.What am i missing as cars could pin the rear wheels when reverse is selected? Great show 🎉🎉🎉

Wonders aloud, “I wonder what welding rod/electrode was he using?”

we need a fixed sprocket drive arrangement so the wheel can be driven backwards too (for an autonomous land rover). do you know of any such axle that would work with these hollow axle wheels for trikes maybe? needs to drive the wheels independently too so maybe two short axles

The big problem I have had with the delta trike is the pitch of the road, need a suspension so I don't fall over and so it doesn't veer off the road either.

Possibly the most ideal design would be to get hold of two single speed freewheel hubs that have internal drum brakes too from the design of the 1930s. They are still being made to this day in countries where low maintenance and harsh environments are the main concern like in India.

With this upgrade over lock differential, turning radius will be definitely improved by a significant amount

What's the brake disc for?

What if you use a one way freewheel, will it be able to reverse?

Where did you get the parts ?

i was trying to figure out how to make one. thank you. do you have video of building a trike?

Done with the rest yet? lol Good stuff!

Can you explain the best way to introduce air to a wood or gas burner .using the hot air from the room you are trying to heat causing drafts. or the colder air from from under the floor Alex.

Where did you get the axel from

You held a piece and said because of this bit. What I want to know is where do you get this bit?

why not power the back tires with separate drive motors and still have reverse, no slippage and more torque

That break disk is useless now though

can we use this system front steering ( TWO WHEELS ) trikes?