Instructables
Picture of Three Wheel Bike Car
IMG_0513.PNG
IMG_0519.PNG
IMG_0909.JPG
IMG_0903.JPG
P1000537.JPG
P1000520.JPG
IMG_0517.PNG
DSCF5425.JPG
IMG_0520.PNG
No gas pump for this car!  A Three Wheel Bike Car, with panniers, a cargo platform, 16 speeds, and a canopy. This project allows for worthwhile grocery trips, pleasurable joy rides, drive-through coffee or bank drive-ups, and the ability to carry what you need, whether that be croquet mallets, warm clothing, a load of groceries, you name it.
 
Remove these adsRemove these ads by Signing Up

Step 1: Get Inspired.

Picture of Get Inspired.
This was an idea bubbling at the back of this bike mechanic's head for several years.To be honest, a recumbent or sit-down design never had appeal for me unless the extra bulk of such a machine could earn its keep by carrying loads. The three wheel design differs from a "long bike" with two wheels, by proving to be awesome on snowy or muddy pavement; there's no fear of laying the bike down in inclement weather. Sketching, collecting cast-off parts, measuring bike path widths, assessing what needed carrying, these went into formulating a somewhat unique design. 30 years of professional wrenching experience made technical issues like drivetrain design and general bike part selection and set up easy.  Welding was required; my skills are rudimentary as to prettiness of the welds. This partly owing to using a basic flux-cored electric welder. But destructive testing showed that the joints have integrity. Mechanical ethics of good joint preparation and careful fabrication essential. Accuracy in measuring and cutting, and so on. The final step of painting the frame is waiting until I'm sure I don't have any more last minute add-ons to weld.  I've been riding the machine since January.
1-40 of 65Next »
reighmey152 years ago
would it be possible to build this out of pvc pipe?
estructor (author)  reighmey152 years ago
reighmey15,
It would be nice to think you could forego welding to build this bike car. However the main concern would be having enough strength at critical points if using PVC.
1. This frame is long by trike standards. In carbon steel, it has a degree of flex as built. This is desireable for comfort reasons. The length allows for more cargo capacity as well. If you just copied the frame in PVC it would certainly flex too much. In steel, the degree of flex is within what I expect it can tolerate for many cycles of use. This allowed me to have a fairly spare and uncluttered frame.
2. The use of quality bike industry parts creates the need to accomodate their inherent design requirements:
-Robust dropouts or other fixtures to firmly secure wheels. (Bolt-on axles, or quick release axles, would crush plastic fittings.)
-Firm places to accurately bolt on disc brake calipers; they have very narrow tolerances and will certainly rub if not precisely mounted. (rubbing is an issue even as delivered on industry bicycles.)
The are other considerations, but I'm not saying they aren't solvable...
I would guess that a PVC frame would need to be designed differently from the ground up. Instead of a few long frame tubes, I picture a truss-type frame for rigidity. Think of a box beam made up of triangulated angles meeting each other to effectively resist bending forces. This will be bulky; room for the rider and for key components will need careful planning.
In one iteration I would consider large-diameter tubing for rigidity. Go big. It does create bulk and space considerations but careful design might overcome that. I'd use 4" in early drawings. If that wasn't going well on paper, such as when trying to accomodate tolerances for the bike components, then revert to many small tubes in a truss frame. (I think this second idea more likely to succeed but no guarantee.) This takes more careful layout, more joints to prepare and construct. The weight would be similar, you'd need more tubes and more joints if using small diameter. Try building up a 7' length in whatever design you conceive, then place it over two supports. Sit on the beam. Is it flexing too much? This is not a very rigorous test but will reveal the obvious "fails" in early experiments. If it bends so much your bottom drags the ground, you know it won't work. However less bending may still be too much for bike part tolerances.
A way to unite the PVC to metal dropouts for wheels would be needed, say by using 1/4" aluminum plate. The dissimilar materials of plastic-to-metal call for a large joint area, I wouldn't make the plates too small. It would be hard to keep joints from loosening unless a good overlap of plastic-to-aluminum was made. I'd think about slotted tubes epoxied to large tangs of metal extending well past the wheel attachment area. (Note that slots for axles cut into aluminum will be more vulnerable than same cut into steel.)
My front wheels are attached with one-sided wheelchair axles and sockets. This puts a lot of load on a single attachment point, but is met by the steel knuckles I made. I don't know how it would go using plastic. I picture the wheels flexing and angling inward at their tops if the left-to-right frame in front isn't made very stiff. And whatever plate is created to unite the PVC frame here to a front wheel would be tricky to keep bonded & rigid. It has to hold wheel for rolling action, and be robust enough for turning forces at the same time. Any flex would lead to rubbing and scraping between wheel and frame. PVC is not built to endure cycles of flex. It has the job of resisting internal pressures on pipe walls, and in house plumbing it must be supported at intervals. So it lacks many qualities that efficient frame-building demands.
I think long-term durability will be lacking using PVC. It may be in the "disposable" bike car category. But it could still be a fun project!

Ok, I tried to make a PVC frame with lots of trusses and gussets and whatever, I want everyone to know that it will not work!! It has way too much flex and it cannot hold weight in the first place, don't try it, just get a cheap stick welder and make the frame out of mild or black steel, that is what I recently used for my trike and it's a little heavy, but it is STRONG. The only possible way to do it would be to buy a ridiculous width of PVC pipe and make a fat, and unorganized frame. Vehicles need to be made from metal!

Estructor, if its not too much to ask, can you please provide and underside view of the steering components under the seat, I'm getting confusing how the cables work with the steering handles. Thanks and again love the build!

Hello estructor, love your project and the background. I am currently erecting a three-wheeled vehicle with two wheels in the front as well. My design is similar to yours, however mine will have a five-horse tecumseh petrol engine on the back, the steering will also be different, but I love the cable idea. I really studied your project and got lots of inspiration, thanks for that! I'm really early in the build process, but I hope to make an entire instructable. Thanks so much!

estructor (author)  OogieMustBoogie4 months ago
Thanks for the comments, glad you gleaned something from my project. I look forward to seeing your result! Will it be motor-plus-pedal, or motor only? Either way, have fun with it.

It will only be petrol powered with a centrifugal clutch so the engine doesn't stall when I come to a stop. The rear axle is the rear portion of an old kent bike I picked up at a yard sale for $10. I'll keep taking pics and creating the instructable. Thanks again!

also with the wheels complete inflated I have about 9 1/2" ground clearance from the base of the vehicle...

estructor (author)  TheEbonieJeneus4 months ago
Hello,
I emailed you so you can send the pdf of project.

Meanwhile, the ground clearance you mention is comparable to a mountain bike's, measured from the center of the bottom bracket (crank hangar) shell. An upright rider pedaling from a saddle located vertically (as in a conventional bike frame, actually between 73° to 75° from horizontal) above this spot would have ample foot clearance, with their heels pedaling level or even with toes pointed down. However, if you are going to be seated recumbent on this trike you'll almost certainly need to raise the crank hangar above your 9-1/2" baseline, or your heels will drag the ground. (This is what I referred to in my first reply.)
Anyway, you've probably thought of this. I hope you're having fun with the project!

Okay Estructor... I am putting together some plans to show you images of the electric recumbent that I have already started modifying... The frame will be rigid with no suspension anywhere but I am using a hub motor built into a 20" chopper wheel that's 4 1/2" wide... My frame from front to rear (hub to hub) is about 6ft long... And it is about 38" wide between the two front wheels... And the center tube going from front to back is about 2" in thickness... I have a PDF but it is unfinished... Could you email me here to further discuss it...?

thelabnificentmediagroup@gmail.com

I am in the process of building an electric hybrid of this bike with 20" wheels all the way around... Any advice...?
estructor (author)  TheEbonieJeneus4 months ago
Hello!
I don't know enough about your build to give too much advice at this stage, but two things come to mind regarding your 20" wheel design:

1. What kind of electric motor will you use ? If using a hub motor, lacing the large motor into the smaller 20" rim may require custom-cut spokes, or else a crossing pattern more hectic than desireable in order to fit shortest stock spoke lengths. I use a Hozan spoke threader to cut & thread spokes when I build tight configurations. But you can also buy completed 20" wheels already built up with an electric hub motor.
2b. Conversely, perhaps you are looking at some other kind of motor which could be mounted on the frame and drive a transfer gear? But hub motors do seem pretty ideal for bicycle wheels and come in kits with good controls, seem well-thought out.

2. My drivetrain design with the crankset centerline comfortably located just a bit above the elevation of the seat (6"?-I'd need to measure) means my heels drop below the frame a bit toward the ground as I pedal. I have good ground clearance using 26" diameter wheels. My shoe size is 40 euro, many riders probably have larger feet & therefore more heel drop. I've used crank arms ranging from 155mm (pretty short) to more typical 170mm length without issue. You'll want to mock up or at least draw and consider your pedal-to-ground clearance using the 20" wheels. I assumed that even though electric, you'll also have a pedal-powered drivetrain? ("hybrid.") I don't think having the pedals located too high above your hips is terribly comfortable, while pedaling too low below your hips, if in a recumbent position, I think is a weaker body position for forceful pedaling. So examine this part of your design. You can create a higher seat mounting platform, & then a correspondingly higher crank hangar/bottom bracket set up. Remember your concern is more than just the length of your cranks; your heels will drop lower than your actual pedal location in most recumbent arrangements I can imagine.
--if you wiil be using a derailleur in your drivetrain, also check its ground clearance, as most long-chain recumbents require a long cage derailleur.
husamwadi3 years ago
WOW this is amazing!!!

I really want one, and if you add an engine on the back, you have an easy dune buggy!

keep up the good work, and good luck for the competition!
estructor (author)  husamwadi3 years ago
Husumwadi, thanks for commenting.

It would certainly be possible to put a motor of some kind on this bike car.

I think I would favor a battery type, and probably would run it to drive the jackshaft with an accessory sprocket. I would try to locate related hardware away from the back wheel, maybe set up the battery at least under cargo platform that is made of expanded metal mesh. But as it is, I am enjoying the freedom of just pedal power. Electric motors, and especially batteries definitely add weight.
The problem with electric motors is that the battery weighs 50 tons or something rediculous :P. And for the added weight, the range of electric motor is crap (10-20 miles at most).

Now here is what I had set up on my bicycle a while ago and it may work for you. The problem was on my bicycle I couldn't really add a whole lot of weight so the battery was only 36 volt (2 miles range at max speed :( .)

try hub motors they work well:

http://www.electricrider.com/crystalyte/
they are a little pricey
estructor (author)  husamwadi3 years ago
Husamwadi, (sorry I spelled your name wrong last reply)
You're right, the weight esp. of battery is considerable, and unless handicapped in some way, to my mind not worth it. Pedaling isn't that hard with this gear range. Might only gain speed--but for only a short range as you said. And then rider is stuck pedaling the weight of motor/battery home without assistance if battery dies. I am a fan already of hub motors. Good weight distribution, decent torque, etc. My desire to emphasize human power, and my specific desire to be able to use the lovely 8- speed internal hub in the rear drove my design in the direction I took. And I'm pretty happy with it.
If I was compelled to build same project with a motor, I would select a hub motor, with a freewheel on it or else a freewheel on the jackshaft. This would accommodate multiple speeds well enough. But I can't overstate the elegance and high function of the wide gear range Sturmey Archer internal 8 speed hub. Over 300% ratio. Better than most plain freewheel/chainwheel stock arrangements.

Aren't the many possibilities fun, anyway. Thanks for your comments.
Gas engines are still good, and they make kits specialized for bikes.

I prefer gas powered bicycles because you can add a very hard to pedal gear, so that when you reach 35mph with the gas engine you can still get exercise from peddaling.

Thats what I would do :)
estructor (author)  husamwadi3 years ago
Ah, husamwadi, I can see you might be a candidate for a land-speed record! I like the way you think.
andrew3185 months ago
I do not get how you made the thing that lets the wheels turn can u possibly send me more pics
charlie_r1 year ago
What you are calling "center point steering" is a quick method to determine Ackermann angle of the steering links.

THIS is centerpoint steering: http://www.atomiczombie.com/tutorials/Rake%20And%20Trail/Figure%206.jpg

Where the angle of the steering axis intersects with the contact patch of the tire.

Ackerman steering:

http://blog.autospeed.com/static/images/blog/2009/03/ackerman.gif
estructor (author)  charlie_r5 months ago

Thanks, charlie_r.

It is as as I said in the Instructable: "I used established principles for laying out the angle of the steering arms on the knuckles. (See sketch about Center Point steering.) You can research Ackermann steering for more about all this."

Hansj310 months ago

what you are describing is literally called bump steer. Some designs use dampners or tuned freq pendulums however increasing steering axis inclination by adjusting camber, caster, and to a lesser extent toe

I8mAll1 year ago
Nice, no better than that, lovely work.
One problem I have found with two wheel steering is that hitting a bump or object with one wheel causes a turning motion around its steering pivot which is transferred to the handlebars.
Recently I was shown an easy answer. Weld the pivot angled slightly outward so its axis points to where the tyre touches the ground. This negates any twisting force and even leans the wheel into the turn.
I admire your stylish work, drawings and directions.
billbillt1 year ago
great
2nup3502 years ago
Another idea for attaching the front wheels is to use a pedal shaft to replace the axle, old style metal pedals used shafts that would work for this. I heated and bent a pair of three piece bottom bracket arms into a 90 to make my steering spindles and used the bb shell as the pivot point. tack welds keep the pedals from unscrewing.
abadfart2 years ago
very nice i have been trying to build a tadpole for a while now. i had a apprenticeship at a recumbent shop and just fell in love with them. just a few quick note a rear derailleur makes a great chain idler. your best bet for visibility is moving color at eye level so a taller flag mast is better.
also smaller wheels up front like thoughts frome a chileds bike will improve stability
PENNY19992 years ago
i believe this is called a motorized tricycle.
i believe it needs a motor to be motorized
estructor (author)  PENNY19992 years ago
Hi Penny1999,
See my comment about my bike car being 100% human powered. (my reply to you was posted as a separate comment instead of as a reply.)
estructor (author) 2 years ago
Hi Penny1999,
Just to clarify, my three-wheel bikecar is 100% human pedal-power. There is no motor.
(I did once think of eventually adding an electric motor after recent knee surgery, but have since found I can get by without it.)
lf you look at other photos in the instructible you can see the pedals, cranks, chain, and transaxle. The bulky rear wheel hub is an internal-shifting 8-speed device by Sturmey Archer, allowing me to change gear ratios and make my pedaling effort match the terrain or desired speed. But all motion is produced by muscle power.

The only external power on board is a small solar panel on the rear rack, that can recharge my 5v music device, or else charge AA batteries for my headlamps and taillight.
estructor (author) 3 years ago
http://www.instructables.com/id/spyder-like-reverse-trike/

Check out this instructable, might be helpful...
Good luck!
mxalive3 years ago
ivebeen trynna make a bmx bike with 2 wheels in the front and front suspension but i need to make a arms and idk how to make them do u have any ideas if so plz email me @ kdtazdan@yahoo.com
thanks
estructor (author)  mxalive3 years ago
Hi mxalive,
Sorry I didn't answer right away. I don't have any experience with fabricating a-arms... But someone here at the site submitted a project that had a front end idea that I think they took from the front end of a quad..it had suspension that I think might be what you have in mind. I'll search here and reply again with name of that project. One thing I would say, if it will be self propelled, you will want to think hard about how to keep the assembly light weight. Even car manufacturer's list the weight of a-arm suspension as a factor. If you plan to scavenge parts from heavier motorized units remember that the weight was acceptable for that use, and that suspension was designed for motorized speeds and kinetic behavior.
You don't have to think too hard about that, except to try and spec frame member material that isn't overbuilt for weight of a self-propelled contraption. Thinner wall tubing, lighter spring assembly, things like that. The weight of a motor is a significant part of load you are trying to damp and control. Otherwise rider weight is main load if framework is appropriately lightweight. I don't know if you are going self propelled.

In bicycle industry, and even on some light weight cargo trailers, elastomer 'springs' have been used, no hydraulic shock, with coil-over springs if travel (length of up and down movement) is noticeable--sometimes no coil spring if travel is short. But a-arm weight I think wouldn't be worth having if only used for short travel..not enough suspension benefit to pay its way?
estructor (author)  mxalive3 years ago
Hi mxalive,
Sorry I didn't answer right away. I don't have any experience with fabricating a-arms... But someone here at the site submitted a project that had a front end idea that I think they took from the front end of a quad..it had suspension that I think might be what you have in mind. I'll search here and reply again with name of that project. One thing I would say, if it will be self propelled, you will want to think hard about how to keep the assembly light weight. Even car manufacturer's list the weight of a-arm suspension as a factor. If you plan to scavenge parts from heavier motorized units remember that the weight was acceptable for that use, and that suspension was designed for motorized speeds and kinetic behavior.
You don't have to think too hard about that, except to try and spec frame member material that isn't overbuilt for weight of a self-propelled contraption. Thinner wall tubing, lighter spring assembly, things like that. The weight of a motor is a significant part of load you are trying to damp and control. Otherwise rider weight is main load if framework is appropriately lightweight. I don't know if you are going self propelled.

In bicycle industry, and even on some light weight cargo trailers, elastomer 'springs' have been used, no hydraulic shock, with coil-over springs if travel (length of up and down movement) is noticeable--sometimes no coil spring if travel is short. But a-arm weight I think wouldn't be worth having if only used for short travel..not enough suspension benefit to pay its way?
urov3 years ago
Hello, I would love to build one of these, but I am struggling to find a way to attach the front wheels to the frame as you did, could you maybe post pictures or some instructions as to how you did it?

That aside, FANTASTIC Job!!

How much is the overall weight of your Bike Car? :)
estructor (author)  urov3 years ago
urov, thanks for the comment.
Good question, the wheel attachment is something many folks wonder about. Lacking special wheelchair or cart hubs, many builders try to fashion a fork type arrangement so they can use ordinary front wheel hubs. I don't like the way that forces you to use a caliper brake, is flexy, and it also makes for slower flat fixes. (with open-wheel attachment such as on a wheelchair, you don't even have to remove the wheel in order to change a flat because no fork blade is in the way of pulling the tire off to the outside.)
The system I used was from a set of quick release wheelchair hubs. I actually modified a pair of front disc brake mountain bike hubs, by converting them to accept sealed bearing cartridges and the solid, side-attach wheelchair axles. I got lucky and the aluminum disc hub's machined recess that came with steel press-in cup races for ball bearings, happened to be the same press-fit dimension to accept the catridge bearings. This lets the heavy steel rods from the wheelchair hubs fit into the disc brake hubs, giving me a clean and powerful set up. I laced the hubs to mountain bike rims.
So the support for the hub is all on one side, with a release coupler that bolts onto the steering knuckle I fabricated. This coupler has a chrome release sleeve that can be moved to release the solid axle for wheel removal. It works similarly to a fitting on a compressed air hose for a nail gun or such, you push the outer knurled sleeve aside and a captured, spring loaded ring of ball bearings retracts, releasing the axle from the sleeve.
However, there are cart hubs that bolt on from one side, instead of being this fancy quick release method. That would be less expensive. I've had the wheelchair hub parts for 20 yrs or so and so can't give you current prices, but retail would have been over $100. If I hadn't had QR axles on hand I would have pressed in some cartridge bearings to a pair of front mtn bike disc brake hubs and then fitted a high strength bolt through the I.D. of the bearings. The largest I.D. possible, to allow a large diameter bolt. Getting bicycle industry hubs ideal so you can use bicycle brake parts. A pure hardware store cart hub or wheel could work but you wouldn't be able to mount disc brakes to that.

When I get a chance, I'll make a sketch of the hubs, axle, and steering knuckle design.
As for the weight of the bike car, too unwieldy to weigh on a bathroom scale, but I'm guessing around 65 to 70lbs total weight.
urov estructor3 years ago
I agree the wheel attachment has(d) me baffeled as well... I just couldnt figure out how I should go about it, so your explanation really helps! shame those hubs are that expensive ;(

As a regular mtb-er I do know that there are axles with 20mm diameters for mountainbikes, there also are 14mm ones. I may look into those a little more to find out if I can modify them, or simply use a wheelchair axle IF they are the same diameter... I can already see, this Project is not something to start without proper research, and preparation.

Thank you for your thorough answer!!
urov urov3 years ago
I also just noticed, I think heavy riders should be concerned about the front axle bending, as it only is attached to one side. What is your experience?
1-40 of 65Next »