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

[William_Hada]

Ingenious use of those freewheel assemblies! I love it!

[stevesimpson]

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.

[flyingbeaver]

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.

[RavenBlood-bnux]

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!

[stubluesjhb]

That was cunning. I love lateral thought.

[lisakingscott]

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.

[karlmyers]

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

[JANDLWOODWORKING]

Wow now that was some really good info!!

[Xayuap]

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.

[brysonwood]

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

[zacharycawthorne-nugent]

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?

[ALIBABU]

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

[Makermook]

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

[pablouvedoble]

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?

[RaperJason]

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

[cristianjoaquindiaz]

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

[gfvt]

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.

[dizzygardener]

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

[MrVince]

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.

[DRUMSBOOKS]

as a MadMax fan I just love this video