New Member, New Quad, Questionable design choices...

Telknor

Telknor

Greetings,

New here and looking to start work on a quad cargo bike with attachable trailer for doubling the cargo capacity when needed. Prior to joining up and posting I was poking around at other projects here and must say that lotharko's wooden quad project and Popshot's 4WS 4WD quad project both caught my attention. I'm thinking of a mixture of the two as I have a full woodworking shop at my disposal and don't have the means or skill to weld metal. I was originally looking at the Velove Armadillo with a trailer. But the price on that monster quickly ended that. $22,000 USD. Then looked into the Pony4 with a trailer and again the price was way too much for my liking. Nearly $7,000 for the bike and an undisclosed amount for the trailer. Years ago, I had a three wheeled rowing bike with lean tilt steering, and it didn't cost me over $1,200 USD. To be fair though it did have very little in terms of materials and most of the hardware was off the shelf bicycle parts. The ground clearance was little over three inches under main body and about two inches under the rowing arms when full vertical. Each arm provided power to the rear wheel on that side of the main frame. The seat frame was able to swing inside the main frame and a right-angle gear setup and small gear box to steer the standard front fork off a kid's bike. The front wheel was 12 inches, and the rear wheels were 20 inches. The row arms adjusted up and down in the pivot points to change the amount of pull on the chains around the single speed freewheel sprocket on each rear wheel and bungie cords pulled the chains and handles back to the default before row stroke. Back then I was living in Florida so very flat terrain and this kind of bike was ok. Where I live now, I wouldn't even strap my worst enemy in this kind of bike. Too many hills to climb in the mountains. For the last few years, I have been using a regular mountain bike with a modified two kid trailer. The trailer was stripped of the fabric covering and the seats for the kids. I bolted on a couple large totes to carry stuff in, and this was my main hauler. About a month ago during a large storm a tree toppled over and destroyed the trailer. This put me on the quest to replace it. But lately I've been needing to haul more than the trailer could handle so I started looking at dedicated cargo bicycles to do away with the standard bicycle and trailer combo. Plus, I'm looking for a more comfortable ride over long distances. Regular mountain bike is ok for short quick run to town and back for a few things that fit in the milk crate on the rear rack. But a full grocery run or going to get farm supplies you need more capacity.

Now looking at the DIY side of this all I want to stay as DIY as possible using off the shelf parts. Now I will splurge where needed for better parts for the job or in terms of safety. I do have Samagaga diffs, axles, and wheels on order. http://www.samagaga.com/ These would use disk brakes either mechanical or hydraulic. Also on order is a Shimano 11 speed internally geared hub and a Bafang 750-watt mid drive. The mid drive is for assistance on hills.

My budget for the project is limited to just $2,000 to $3,000 for parts and materials that I don't have on hand already. The already ordered parts have eaten a good chunk of that. But, if need be, I could add another paycheck or two over the course of the build. This isn't an over the weekend project and I expect it to take a few months.

Where I'm having issues are the suspension and steering geometry. I don't fully understand the needed angles on the front axle assembly. The suspension I'm at a loss on what kind to use. I can get the standard mountain bike rear suspension coil over damper style shocks easy enough. But the new bow arm suspension has my attention as does the torsion suspension that was on a strange 4WS bike linked in another post. Don't know where one would even get either suspension type for a bicycle project. They only appear to be on production bikes and not parts one can just buy. Also, the terms fiberglass and composite being used to describe the bow arm suspension automatically has me thinking they are expensive as hell.

So, any insight or pointers on the steering or suspension would be helpful.
 
Well you have already spent some dosh , however the above seems a little short on requirements ?
So :-
How wide can it be ? does it have to pass through a door , gate or street furniture ?
How long could it be ? longer means bigger turning circle , does it have to be transported by car or truck say if it breaks down ?
How high do you want to be sat ?

A trike is easier than a quad especially if it is a Delta

Are you sure there is nothing in Brads plans that could be a basis for a build.

Look here Wooden car project he builds a moving object with minimal metal work skills , the design is not what you want however the methods might be ?

It may be better to start simple and build modular like Lotharko or the Pony4 is , in other words get something rolling with just simple 1WD and steering.

It is far easier to improve an existing vehicle by riding it and listing it's short comings than it is staring at a blank sheet of paper.

The next level of complexity could be electric assist

More riding/testing !!! you can never have to much.

The level after that if you felt you needed it could be suspension.

Each level makes the whole project more complex/heavy and liable to turn down a dead end that it is possible you can't get out of.

Least you then have something to fall back on that you know works ?

Lotharko project unfinished , however he usually responds if you Private Message him from here ?

Anyway to much rambling , good luck we like pictures !!!

Paul
 
Yes, I actively follow the Way-out West channel on YouTube. Been following his little wooden cycle kart for a few months now. The bobbin steering is interesting, but I feel like it would eventually cause issues.

As far as dimensions on my quad I'm shooting for something in the 30-to-34-inch range for width and about the length of the Armadillo quad with trailer. 30 inches would fit through a standard door with room to spare while 34 inches (width of Armadillo) would technically still fit through a standard door, but you have to really be able to swing it open wide to get the clearance. The extra few inches in width would make it more stable in turns and I know I've seen reverse trikes up to 38 inches in maximum width and I think 40 inches is maximum your allowed by law for a bicycle or bike trailer of any kind.

Don't plan to transport by vehicle. The plan is to carry spare parts, tubes, tools, pumps, extra batteries, parts for solar system, and possibly a few full wheels and tire combos on board in a series of lockable equipment storage lockers not part of the main cargo area. Most of the trips a month are 12-to-15-mile round trip with only one trip being a monster two day nearly 400-mile round trip. Max load expected to carry would have been just below the maximum load capacity of an Armadillo with trailer.

Seat height would be about the same as a Pony4 or the Armadillo. Gound clearance the same as these two examples. Maximum height of bike and cargo boxes equivalent to Armadillo or maybe shorter to reduce roll over on sharp obstacle avoidance maneuvers. Have considered main cargo area of trailer to be dropped down to lowest point on main quad frame to lower center of gravity of the load.

This while my first quad is not my first time on a trike. As stated in original message I had a delta trike with lean steering and rowing powertrain. On another post I mention about the rough roads around here being bad on a standard reverse trike that I borrowed from a friend to get a feel for the laid-back recumbent riding position and see if I wanted to go that route. That trike was at most about 3 inches of ground clearance below the seat where the frame was too low, and it would constantly bottom out on the rough back county roads. Since I need to use these roads in addition to the paved roads higher ground clearance and suspension is needed.

I have a few adult sized soapbox derby racers and a cycle kart style racer at a friend's place nearby that I can go look at if needed. They are built with bicycle parts but are not street legal. The cycle kart counts as a go kart as far as Missouri is concerned which are not allowed on public roads. The soapbox derby racers have no means to propel themselves, so they are under ridicule by local law enforcement unless there is a race event. Though I imagine it wouldn't take much to make one pedal powered. The soapbox racers have a simple drop bar front axle on two single leaf spring suspension one on each frame rail. Much like the video here. Cyclekart - Part I (youtube.com)
 
Also, I've not been able to view any of Brad's plans as that part of the site has been down for redesign for over a month now. But he did say it's coming back soon so I'll be able to have a look soon.
 
No, I hadn't seen this one. I was at a local soapbox derby and cycle kart builders shop the other day looking at the simple leaf and drop front axle on the twin rail fame that they use. Light weight, strong, and works. They abuse the hell out of these things during the races when they have them. Haven't had any since covid started in 2020.
 
Also trying to figure out what to skin the cart with. Was looking at the various ways that velomobiles are covered. Coroplast while easy to get and work with leaves unsightly and rough edges since it basically plastic cardboard. Polycarbonate panels a few mm thick might work but after a bit it gets heavy and expensive. Though of using the skin on frame Kayak style of covering it. this would be waterproof and light.
 
Hey Paul, you see this video where the same guy is using a ladder as the frame for a different bike? I was actually thinking about if this would work or not just last night. Since I have like 20 of these ladders all over the property. Wasn't sure if they would be ridged enough in a laid down position to work as a quadracycle frame. But I guess once frame and wood floor for the cab and cargo area are on it then it would be ok. I can try it as I have plenty of ladders. Time to experiment.
 
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That has a very convoluted development life , and is still not ready !
I think it started out RWD then suspension on front which he could not get to work properly.
The IIRC he went to FWD which then necessitated RWS , that never goes well.
So you will see loads of videos/threads on the German form of a device with the same name but never looking the same.

The ladder may work however I think you are always up against it being hollow at most of the points you want to attach something ?

Paul
 
You could use recurve bow limbs for suspension arms. Cheap on ali-express. You'd need to line several up and fasten together to get a good rate. Equally you could buy 5 to 10mm fibreglass sheet and cut to shape. Ebay had / have some listings for this when Iooked at this.
 
Have you found this Forum ? Finnish projects list

Here are a couple taken from there that may have some ideas of interest to you ?

Quad load mover

14650692.jpg

1CV
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very comprehensive build instructions with suspension and electric assist and an unusual wooden chassis to boot.


Lots more to look at there.


Paul
 
Hey Paul, Yeah, I found the forum post for the woody with blue rims a few days ago. Was reading up on his issues with it not doing so well on snow as it only has one rear wheel driven by the pedals and the other by the e-hub turned mid drive. He's also battling with rain on the windshield as he went with a spinning disk on or in the windshield like large ships have on the bridge windows. As far as the ladder idea from the one fellow I've tested the ladder bolted to some boards about where the axles would be placed on buckets. Then mocked up the above frame bits with a kayak mesh seat and the cargo area with a sheet of half inch plywood. All of this bolted to the ladder with U bolts on the rungs and side rails in temporary setup. Then sat on it and did a bounce and lean test of sorts just to see how much the ladder would flex. The ladder by itself on the 2x4 "axles" flexed a bit in the middle but once the sheet of plywood was bolted on the flex went away enough that I'm willing to test this more. By end of the month, I should have a mockup rolling chassis to test by riding it down the hill on the back half of the property. It won't have pedals or drivetrain bits in just main frame, suspension, some 20-inch wheels that I have on hand for garden carts, steering, the seat, and the plywood floor to the cargo area. The hill is both semi smooth and rough terrain which is idea test for the back road conditions that I would be traveling on.

No, the actual quad is not going to have 2x4 axles. I only did that to get the approximate height of the seat from the ground and the cheap pine 2x4's had just enough flex to them to give a rough simulation to the suspension and effects on the ladder idea overall.

The other quad bike you linked is most certainly not bike path friendly by the state's rules. Several of my routes I would need to travel are reliant on hiking/biking paths. I have already been given the ok on anything up to the size of an armadillo with a trailer. Anything bigger and it starts to get into a gray area on the rules and if I have to tag it as a moped despite it not having an engine or the speed of one. While also having to follow the same rules as driving a golfcart on public streets. Which would mean no bike paths or some of the other roads I currently can be on.

Yes, I will get pictures of this crazy test setup and maybe a video if people want to see that.
 
I wonder if the flex in the ladder is beneficial if it helps keep all 4 wheels on the floor , although if the ladder is aluminium it is probably a good idea to eliminate flex as it has poor fatigue properties.

The other quad ? well I did not expect you to build a side by side 2 seater however the rest is all on spec for what you are trying to achieve ?

Paul
 
Yeah, the ladder is mainly premade aluminum I-beam frame rails with the equally spaced cross members. I would probably run angle iron or some other material with the predrilled holes some many inches apart on the outside of the ladder to give it a bit more rigidity and optimal places to mount stuff. The I-beam rails of the ladder would be the main load carrier, but it would be boxed in with more aluminum flat strips and sheets. I have the ability to cut, bend, and drill metal parts just not weld them as I lack a welder and the skill to use it. I was looking at taking the approach that XYZ Cargo did in a bolt together design that can be modified and added on to with ease rather than something that needs to be cut up or completely started over on once a part is too mangled with "errors". This way the error might just be moving something to the next set of holes and playing out or in the adjustment rods or links that hold things in place at certain angles or lengths.

The XYZ Cargo group uses aluminum square tubing both on the commercial units and the DIY plans for their bikes. The tube is 25mm x 25mm x 2mm wall thickness. My main concern with using their plans is that it's hollow and very easy to crush it while tightening the bolts. I have already tried to build a bike trailer based on their DIY plans. I also found that many points require you to drill out holes in the tubing that leave very little material supporting critical load bearing parts. For example, the tube sections that the wheels bolt onto at are 30mm x 30mm x 3mm wall thickness and you drill a 12mm hole through it for the 12mm single side mount wheel axle to pass through. There is nothing supporting that axle except the two 3mm walls which may or may not be crushed when you tighten the axle nuts to hold the wheel on. There is also only 9mm of that 3mm thickness above and below the axle bolt. This to me isn't enough when you factor in there is no suspension of any kind on a bike that this is how the steering wheels are bolted on and it needs to carry the rider and a couple hundred pounds of stuff on the cargo versions.

This is the free DIY reverse trike plans here. https://www.n55.dk/MANUALS/SPACEFRAMEVEHICLES/DIY.pdf My other fear with this design is that it's a ton of bolts and lock nuts that could over time loosen on rough terrain or crush the thin wall tube with all the flex points.
 
Also am I missing something here? It seams to be a trend for people to take the large rear hub motors and mount a front BB sprocket to where the disc brake would be. Is there an advantage to doing this over just leaving the hub motor in the wheel or using a motor at the BB crankset?
 
You can gear it up or down to better suit the application. Also a mid drive must run through bike chain so has a limit on what that will reliably take. Using a hub motor in the way Emil has on his quad gives you the option to use stronger chain so you can use a stronger motor.
 
Ok makes sense. This is why Velove does this with the mid drive unit on the Armadillo being installed in the frame right before the rear axle. They then run a double chain off the jackshaft that combines the pedal drivetrain and the mid drive into one output. Though being limited to 750 watts does it make a difference if it's a 750-watt mid drive at the bb crankset or a 750-watt hub motor at or near the final link in the drive train. 750 watts is still 750 watts no matter how you place it. Though I suppose I could use a stronger motor and limit it to 750 watts for the legal aspect just to have the higher torque the larger motor offers. I will have the ask the people that make the rules here.

I'm also looking into the pneumatic and hydraulic drive systems that have appeared on some bicycles. Someone I know is trying the hydraulic drive option on a reverse trike touring bike. Interested to see how his testing goes on that.
 
Found this about an hour ago and was wondering how practical it would be to use this in the winter. This company makes "snow bicycles" that have a ski in front and a caterpillar track in the back. They also sell the track units by themselves. Thought of getting two to stick on the rear axle in the winter and have a halftrack cargo bike when there is snow everywhere.

https://ebikebc.com/en-us/products/flex-snowbike
 
In theory a smaller chain will exert less drag so a motor close to the drive axle will suffer smaller losses. In practise I doubt you'd notice the difference given equal motors.
 
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