Cart Bike

Step 5 Test ride

The front brake lever won't be useful unless the shifter is attached to it. I will modify the left handlebar for the shifter when i find one without a brake lever attached.

On test rides it does not corner well. Steering is very wide turns and sometimes the cart teeters on two of the wheels on one side. I'll definitely be playing around with the details. This will make a great rig to make trips to the post office for the bike shop. The cart bike will be a great addition to our town parades.

Please note that this is not the first cart bike. See some of my inspiration here and here.

Comments

[clazman]

I'd hate to be riding this deathtrap when the little wheels attempt to navigate a sudden change in road surface. Rolling resistance is inversely proportional to wheel diameter.

Haven't you ever tried to push a shopping cart over a rock of only a fraction of an inch, oh I'm sorry, several millimeters in cross section?

Something to do with trigonometry and force vectors and all that.

[mrcurlywhirly]

I love your ingenuity but would not touch this design, looks pretty dangerous to me.
Seems to me you are comprimising the ridability of the bike and your safety by using the shopping trolley on the front end. If the basket is what you want then wouldn't it be safer to hack the unroadworthy trolley wheels and frame off, get a short axle and put some bicycle wheels (or lightweight bigger diameter wheels) onto the basket, then fashion a tube hitch and use it as a bicycle trailer?
Probem with this design is that shopping trolleys are relatively heavy, and only designed for short trips on smoothish surfaces. For anything to do with bikes you want something as lightweight as possible.

[bo88y]

The smaller diameter of the shipping cart's wheels make this unit unable to roll over any obstacle higher than about 1-1/2 to 2 inches. A temporary roadwork trench could send the rider end over end.
Years ago, when people still returned shopping carts back to the front of the store, I was doing just that, and because I was in a hurry, I was moving at a pretty good trot, and I hit a nicely cut little trench cut into the pavement of the parking lot, filled with asphalt to a couple of inches below the rest of the pavement. The handle of the cart got rammed back into my stomach, pinning my hands to my stomach, and I went head first into the cart as it went end over end with me in it.
Having entertained my friends during my misspent youth by taking head-first tumbles down staircases and walking away as if nothing happened, I was well prepared for the shopping-cart mishap, and didn't get hurt, but for those without specialized skills for rolling around on pavement, this sort of thing could be painful, especially with the higher speed of a bicycle.
This bike requires more alertness to conditions than most, and while it might be OK for short trips, ti wouldn't be good for commuting. Safety-wise, this project has "Don't try this at home" written all over it. But other-wise, it shows some great, um, imagination.

[Awesomeness in a can]

So is there some special class you have to take to learn how to roll on pavement or do you just learn on your own? Because I think I can join you in knowing how to roll on pavement, I've fallen a lot too.

[mrcurlywhirly]

I should probably expand on the 'dangerous' comment.

Suspension front end bikes do the majority of their braking on the front wheel - as opposed to solid front end bikes. How will you stop this machine with even a half load of shopping in it?

Imagine a slight downhill incline, fine misty rain, and the Volvo wagon of death slowly turning right across your path... maybe an airbag, ejector seat, or a parachute brake could be a good inclusion!

[adamantchess]

couldn't you remove the tires on the shopping cart and install a single tire to the shopping cart? then you could also get the entire cart to articulate and it would be a regular bike only with a giant basket.

[ginofultano]

Cool idea, however I wonder if cutting off the solid wheels and installing larger pneumatic tires would help with high speed stability. Harbor freight has wheels with for pretty cheap.

[BGreenHVAC]

Sure go with China freight. It would be better than tiny solid wheels. I'd weld a 5/8 rod (axle) a little bit in front of the existing cart's rear wheels. Then thread the ends for a nut and cotter pin. The "China freight" wheel should slide right on. Tighten the nut so the bearing will turn. Drill a hole slightly larger in diameter than the pin and use the pin to prevent the nut from coming loose. I would remove the cart's original wheel and use it for something else.

have fun

[arpoky]

Perhaps cutting off the back wheels of the cart, making a wheel-well, and leaving the front wheel of the bike on might make it work better? It will take out a lot of room in the cart basket, and may just defeat the whole purpose of attaching the bike to the cart. I don't know, its just a thought.

[george3092]

or stop the REAR shopping kart wheels from turning but allow the front ones to turn

[clisnek]

genius.... im going to make this and when i do, im going to do what you said but make a longer fork to use with a bmx wheel which would jsut take some storage space from the under carage

[themadtreky]

take that to an even smaller scale sing the front fork and wheel off of a child's bike, or perhaps adapting a child's bike front fork to accept a wheel barrow wheel. that way you could load more into the cart w/o running the risk of collapsing the rim or damaging the tire. you'd still be able to turn but would lose less space.

[scottishtommy]

mmm aint it hard to control and i think you would have to avoid shopping at asda

[Cimarron_warrior]

I built one of these about 10 years ago. Had a blast designing, scavenging, and then building it. A couple of things I did different was I cut the under carriage off the cart and used forks and front wheels from two like bikes and mounted them to the sides of the cart with muffler clamps. Then I took and hooked the front wheel mounting hooks on the fork of the bike used in this to the little bar running across the bottom of the cart basket at the back of it. It was a pretty stable ride but, as you have mentioned with yours cornering had a lot to be desired. My girlfriends youngest son loved riding it all over the neighbor hood and was always ready to head to the corner store just so he could show it off. You have done a very nice ible here too bad I didn't know of this site back then or I might have beat ya to this......LOL.

[Chris D.]

I once did this after getting a flat front tire in the middle of knowhere.. all I did was use my bikes front tube to tie the front fork down and onto the bar where the front axel would sit onto the cart, then tied it down as good as I could.. I made a 10 mile ride back and got all sorts of unusual looks lol

[candijunkie421]

what if you left the front bike wheel on then just cut pieces out of the shopping cart to accomodate  for the wheel.  with the cart handle through the handlebars the cart should still turn without the wheel getting caught in it. you could make some sort of cover for inside the cart to cover the wheel (older bikes had those metal protectors over the tops of the wheels) you could easily affix a wood box to fit over the wheel so you could store stuff in the cart and not get caught in the wheel. i dont think the structure of the cart would be compromised with as many places as they are welded and the strength of the metal and even more so with a plastic cart.  in that case you could probably raise the handle bars to lift the back wheels of the cart off the ground and make it even easier to turn with just the front wheels though that might make it off balance when you turn? just some thoughts. 
i also dont think it would work as well on the back of the bike unless the front wheels are off the ground because i think it would have problems turning with so many wheels having to turn.  hope these help improve it!

[candijunkie421]

my bf just suggested if you didnt want to take a ton of space out of your cart you could put a smaller tire on too :)

[daniel.b]

how do you turn

[Glockenator]

you can turn. the handle of the cart is on the fork allowing it to turn

[ReCreate]

you can't you just hope that you never get to any sharp turns

[dasdew2]

can you ad a softer seat and motor

[gitar586]

You should try and jump that.

[danamos666]

the main problem with the stearing would probably be coming from the anglae of the forks, ive done this before, and with 100% vertical forks it works better, if not completely wonderful

[sebberdreng]

Is it hard to ride when the front is a cart and can you turn good?

[Waldie]

I can see why it would be rougher to steer than an "Army Lorry". We're trying to turn a bike, which leans to turn, into a tricycle. A trike is inherently stable - three points define a plane. The situation could be eased with some means of flexing the frame, vis-à-vis the cart - Hmmmm - cut the handlebar post past the knucle, and rejoin with an internal spring? Yes, that would work, but a simpler fix, pending finding the spring on the "discount" market, would be a cut, with a sleeve inside that the stem rolls on. We then replace the zap-straps with springs. It might help to put a dummy axle in the drop-outs, around which the springs can wrap.

[zieak]

I did that - sort of. I put a threaded rod through the drop-outs and connected that to the lower part of the cart. The only problem came when the rig rolled over a rise or dip. Then cart wheels lifted off the ground because it couldn't articulate. I considered suspending the bike from chain so it could lean also.

[Waldie]

Yeah - I can see that that's what would happen then. The trick is to get a single point of articulation, the stem, and hten connect the forks with a spring system, so it would generally stay erect, but could lean and pivot back & forth as required. If one could eliminate the nose wheels on the cart, then one should be able to concentrate on the lateral flexion. However, that might (in extreme loads- but who are we kidding - isn't that the whole point?)put too much stress on the steerer and the handlebars. We'll have to think about this.

[Gridnack572]

ya know you could leave the front tire on and just rig the cart to the BACK of the bike you would still have style AND steering .... although i'm pretty sure most of you have thought that one over but still a "cartcycle" as i would call it looks cool

[heathbar64]

Hey cool idea! this would firmly cement my title of mad scientist. It seems like the small wheels on the cart would fall into the tiniest little chuck hole in the road. Why not install small bike wheels on the back of the shopping cart. If you, removed the front casters, the whole thing would then steer like an articulated machine. you would just have to fix the bottom of the forks more securely to make it work that way.

[enahs]

Replace the back wheels with one wheel in the center so that the whole bike could still lean. Leave the front casters on but make sure that they have some clearance so that they only hit the ground when you lean to turn.

[rotinaj]

You could use some old rear shocks instead of zip ties.

[nuentoter]

I think if you added a horizontal bar across between where the 2 rear wheels of the cart are, and placed small tires there, possibly 2 tires 2-3 inches apart, and leave the front as is. it might work a little better.

[Berkana]

You can't steer easily because the front wheels of the shopping cart are not casters. On its own, the shopping cart steers from the back, like a boat steering with its rudder, whereas the bike steers from the front, like a car. By hitching the two together, you're not going to get a very good steering effect; the front wheels of the cart will resist your steering because they won't want to slide. My suggestion is to hack the cart so it has one set of middle-mounted casters. Get rid of the front wheels of the cart and re-weld the rear casters to the middle of the tubes they're connected to.

[zieak]

This cart has casters for the front and the back are rigid. I think the head tube angle forces the rider to fight the back wheels a bit - but i'm no engineer.

[sweavo]

The important measurement here is whether a line drawn through the headstock to the ground hits the ground in front of the point of contact of the wheels and ground. If so (it looks like it does) then the vehicle will pull straight. So I imagine this vehicle is fun and stable to ride, requiring a strong arm to turn it at speed. Shopping carts here in the UK nearly always have casters on all four wheels. Imagine what I thought when I first saw the pic!

[Berkana]

Now that I've looked at it again, it does seem that the casters are in front. Hmmm. . . The head tube angle definitely will try to tilt the cart, which will resist that. Considering the head tube problem and the rest of the factors involving steering, I'm not sure you can hack a conventional cart to a bike and get ideal steering; a hack extensive enough to make that work would probably not be worth it; better to buy a cargo towing rig or massive panniers.

[jongscx]

...or it could just be that instead of moving a really tiny mass with a really small footprint, you moved to something really heavy (especially if the cart is full of stuff) with a pretty large footprint... just a thought.

[Great White- Shark Owner Of GWsFBA]

Jongscx, If your point is that creating such a bike that can hold more, is only encouraging more consumption and thus larger footprint, then that is a interesting good point, I did not even think of that, and I am a huge environmentalist. Now keep in mind, if your post is sarcastically pointing out the above, then to slightly counter this point is that by using these carts, you are either taking the carts directly out of the garbage dumps (like zieak points out; which is awesome) or one is indirectly pulling the carts out of the life span which will result in being in a garbage dump. I am sorry, if I miss-understood your point.

[jongscx]

Oh dear god... did I just get mistaken for an environmentalist? *shoot's self * (sorry, bad experience with extremist environmentalism using shock-and-awe tactics on my on my way to calculus... psh... dead babies...) No, you're thinking of footprint in the sense of "global footprint" or "environmental footprint". I'm talking in engineering terms, perhaps I should have used "wheelbase" instead. (Personally, I don't care if they're carrying cans to the recycling plant or over-packaged single-serving donuts from walmart.) My point was that if you built one of these , and carried, say hollow blocks in them(or an equivalent weight of sacks of organic locally-grown soybeans), and tried to turn it while riding the bike... it would be difficult because of the momentum of what you're trying to turn would resist turning. Another thing would be that you're effectively doing two things to decrease your stopping power, increasing the maximum carried weight and removing the front wheel (which if I'm not mistaken is responsible for a good 70% of braking power anyway) Oh and now that I reread your post, I appologize for my first sentence, but hopefully the second should explain it.

[Great White- Shark Owner Of GWsFBA]

jongscx, No problem; however, i must state that I understand why some environmentalist are more extreme than other environmentalist. It is not like they are fighting for earning more money, they fighting to prevent the lost of species (in just two-hundred years lost 90% of the species on Earth, that existed at that time) or global warming affects (the worse disasters human will have ever faced and the clock is down to 18-years to only decrease the disasters' strengths and way too late to stop it from happening) and our politicians keep worry about not upsetting the super rich business world and some customers backlash. JFK got USA in space in less than 20-years, where are our JFKs? Those are great points. I was wondering about how the turning work myself, because of the wheels are just so small and the cart is so big.