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As the title says. You would be pushing the 'trailer' rather than pulling it. Does this exist?

The one advantage over a trailer would be you can see your cargo.

My very basic design idea is to attach the cargo carrier to the axle of the front wheel (allowing up and down tilt to get over curbs) and have one free to castor 20" wheel in front. Steering would be harder since you have to move the whole "trailer" but it's hard to say by how much.

In summary I think it's possible to build and ride around with such a thing. But does it exist as a commercial product or diy project?

ETA: Apparently my wording was not clear enough: I'm not looking for a cargo bike with the cargo in front (like a bullit or backfiets or babboe or flying pigeon or or or ...) but for something that attaches to the bike unlike a trailer, namely in the front. Also I'm honestly at loss what to do with the answers - most of you point out relevant problems, none tackle the actual question (though the answer is likely no, and this is always hard to answer).

Weiwen Ng
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mart
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    With a castor front wheel, do you believe a person would be have the strength to maintain control of the steering? Have you ever tried to push a loaded supermarket trolley across a slope? Roads always have a slope.... – mattnz Nov 07 '21 at 20:15
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    And even if you have roads without slopes, (as happens in some cities,) roads have humps and holes (and often potholes which are big enough to eat most of a 20" wheel. – Willeke Nov 07 '21 at 20:20
  • I thought I'd seen them as an attachment rather than whole bike, but can't find an example of that now. And they're meant for children, not cargo. But there's: https://www.wintherbikes.com/product-items/kangaroo-luxe/ – OJFord Nov 08 '21 at 12:16
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    This made me think of..well, I don't know what its called, but basically an ice cream bicycle which is similar to what you're describing. However, this is not a detachable trailer..it's built in so perhaps off the mark. – rob Nov 08 '21 at 13:44
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    It's impossible to prove a negative, that is, it's impossible for anyone here to prove that such a trailer doesn't exist. However, there are fundamental problems with the idea that lead me to think that it would not be commercially viable. – Adam Rice Nov 08 '21 at 17:34
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    "Almost, but not quite entirely unlike" a trailer (after Douglas Adams) – Peter - Reinstate Monica Nov 08 '21 at 19:02
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    I don't understand the advantage of seeing your cargo. If you're worried that it might fall out, then it should be secured better so that can't happen (which is true whether it's a child, a dog, or groceries). If it falls out of a rear trailer, you can go back and pick it up, if it falls out the front, you're going to run over it. But if you really want to see your cargo, I can keep an eye on my dog in the trailer using the mirror on my sunglasses, I just tip my head up. – Johnny Nov 08 '21 at 21:33
  • @Criggie: Why did you change the question to be about a powered device? It's supposed to be something you push in front of you, not a powered device that pulls the bike. – user2357112 Nov 08 '21 at 23:43
  • @user2357112supportsMonica good spotting - I must have had a senor moment :0 – Criggie Nov 09 '21 at 01:11
  • @Johnny for city/utility riding, it's quite common (in Europe) to have a basket in the front in which you can quickly put your belongings. Having it in front and seeing it is more reassuring than having in the back, mostly related to theft. If it's in the back, someone can sneak and take your belongings without being noticed. – Rеnаud Nov 09 '21 at 08:03
  • and have one free to castor 20" wheel in front so you're practically going to double the length of a bicycle and convert it from a usable, portable, rigid framed thing that you can wheelie up onto its back wheel to fit in an elevator, or lean forward far enough to look into a stream of traffic without sticking your front wheel into said stream of traffic when crossing between parked cars, into a cumbersome, bulky, floppy frame that doesn't really fit anywhere? I'm not sure I understand the market appeal; can you list the positive aspects of your design or the problem it solves? – Caius Jard Nov 09 '21 at 09:34
  • The only time I recall seeing trailers extensively pushed is by special tractor units that load ferries. Having a tractor unit where the cab spins round so it can pull or push a trailer means that trailers can be loaded into corners and bunched up tight against each other without the tractor unit getting in the way of the operation. This is such a narrow use case though; pushing a trailer is inherently massively more unstable than pulling it – Caius Jard Nov 09 '21 at 09:40
  • Next time you're at the supermarket, try turning the shopping cart around and pushing it backwards from the front the whole time instead of the normal way. (Assuming it's not one of those carts where all 4 wheels swivel). It's not impossible, but it's a lot more difficult, increasingly so the more weight you add to the cart. A bicycle with a front trailer would be kind of like that. – Darrel Hoffman Nov 09 '21 at 21:52
  • @mart Hey there - its a year later now. Did you make progress on your plans? If so, its totally okay to post and accept your own answer sharing how it went. – Criggie Jan 19 '23 at 11:43
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    @Criggie no I didnt – mart Jan 19 '23 at 12:45

5 Answers5

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There is technology for this, has been there for many years, called 'bakfiets' in Dutch. A bike with a big load bed in front of the rider.

https://commons.wikimedia.org/wiki/File:Bakfiets_openluchtmuseum.jpg

The problem with containers which are not on the bike/trike itself but running on their own wheels is that you need pretty big wheels for the container to move over uneven bits of the road, and you need a good connection to the part of the bike you sit on, with a good option to steer, as you will need both parts to move together and turn the front part or the wheels under it in a way that will steer the whole of the combination.

As a recumbent rider I have ridden some 'strange' bikes/trikes and in the past I have rented a 'bakfiets' as the one in the picture (see link above.) And I have moved many loads on their own wheels as well while walking in front of them and behind them, and never found it easy to steer a load in front of me.

That brings me to two reasons to have big loads behind the rider.

  • you do not need to see over the load.
  • you have an easier time to steer a heavy load.

For smaller loads there are many different kinds of bikes, with load beds in different positions, before and behind the rider, before, above or behind the steering wheel(s). But I have never seen or heard about a kind of bike that takes up containers on their own wheels.

With one exception, there are several ways to combine a wheelchair and a bike behind it, sometimes using the big wheels of the chair, (tilting the chair so the smaller wheels are off the ground,) and most of those are a dedicated combination, where only one brand/make of wheelchair and only one kind of bike can be used to make a working team. A google search revealed at least three but no usable photos for here.

Willeke
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  • Good answer, but I think the problems with this design would be very different from the problems with a bakfiets. I think it would actually handle uneven bits much better, simply because the load is distributed over two wheels. But how well the steering would work, I have no idea. – leftaroundabout Nov 07 '21 at 21:44
  • With a traditional bakfiets the load is distributed evenly over two front wheels but heavy loads make for heavy steering. – Willeke Nov 07 '21 at 22:51
  • I've heard about those, "Urban Arrow" brand for example... – NoBugs Nov 08 '21 at 03:05
  • Urban Arrow are modern transport bikes. Traditional ones are a lot bigger and can load a lot more but are also heavier and harder to ride – Willeke Nov 08 '21 at 05:08
  • A well-built 3-wheel bakfiets is easy to steer, but requires some retraining of a cyclist's natural instincts and muscle memory. The first time I rode one, it took me all of 10 minutes before I crashed at full speed into a fence. But with a few days of practice, I could pedal it across terrain and roads all over Europe with little difficulty, with a load of almost 300 kg. – Sebastian Lenartowicz Nov 08 '21 at 12:41
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What you're proposing would not work: your design would effectively be steering from the middle of the (combined) vehicle. You would need to transmit the turning action to the frontmost wheel, which is what a bakfiets does. There are cargo bikes with small front wheels and load decks above them (and conversion forks for same), and there is a converter that turns the bike into a trike with a load deck between the front wheels.

Adam Rice
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    Additionally, the trailer would be pushed from one-side of the front axle, so its not even in-line. However it would be easy enough for OP to test by bolting a towball/hitch to the front wheel and try it in a wide-open isolated safe space with no obstacles. There's a certain finality to discussions when the theoretical is made real. – Criggie Nov 07 '21 at 18:15
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    @Criggie right. The more I think about this, the weirder it gets. In an articulated, leaning three-wheel, one-track vehicle, the middle wheel would probably bounce off the ground in turns and the vehicle would oscillate side-to-side around the middle wheel. It might be interesting in a sort of circusy "can you control this?" way. – Adam Rice Nov 07 '21 at 18:34
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    It would also depend on whether the "trailer" (leader?) was rigidly connected to the fork, or to the frame, or it swung freely. If it swung freely, it would jackknife immediately (like a semi backing up). If it was rigidly connected to the fork, it would be impossible to steer. If rigidly connected to the frame, I think you'd get the bouncing effect I described. – Adam Rice Nov 07 '21 at 20:36
  • @OP Do it! Take video if you can. Worst case I can try this in the weekend. – Criggie Nov 07 '21 at 20:40
  • @Hobbamok if I understand the original question correctly, it's describing something very different. – Adam Rice Nov 08 '21 at 14:11
  • @AdamRice i read OPs clarification and yeah I read it completely wrong the first time, sorry – Hobbamok Nov 08 '21 at 14:35
  • @Adam "jacknife": Exactly. You cannot have a (regular) joint between the "pushed trailer" ("leader"?) and the bike. It may be allowed to go up and down but not left and right, which means you have to steer the trailer wheel in addition to, and more than, the bike's front wheel. The "leader" then becomes integrated into the bicycle, making the composite a new kind of vehicle. The best bet would be to "load" the bike's front wheel onto the "leader", getting it off the ground, and steer the "leader's" wheel with it through some transmission. – Peter - Reinstate Monica Nov 08 '21 at 19:13
  • I think the only way to make it work is to not have a bicycle front wheel but to use the 'trailer' wheels instead. – Willeke Nov 09 '21 at 16:05
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Do cargo "trailers" mounted in front of the bike exist?

Later

But does it exist as a commercial product or diy project?

The design description in the original post:

My very basic design idea is to attach the cargo carrier to the axle of the front wheel (allowing up and down tilt to get over curbs) and have one free to castor 20" wheel in front.

Here is a rough sketch of the device in question.

enter image description here

An attachable "preceder" (since it does not trail the bike it can't be a trailer) will be difficult if not impossible to steer. The amount of leverage the handlebars provide to control the front wheel is much less than the leverage exerted by the preceder. With the added weight of cargo the situation becomes much worse.

Riding with 5 pounds of cargo in a handlebar bag dramatically effects steering but it's manageable. This would be orders of magnitude worse.

No, an attachable wheeled cargo device that mounts to the front axle does not exist as a commercial product or a diy project. (unless you start your own diy project)

It is much easier, cheaper and safer to attach cargo to the front of the bike using one of the multitude of front racks, baskets or panniers available.

Here examples designed for larger loads:
enter image description here
enter image description here
enter image description here

It would be wonderful if you built one and rode it with video of the whole experience. Please be sure to post a link in your question.

David D
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  • Ok you are probably the first to actually understand what I meant. Your criticism of my idea is sound - I don't think the analgoy with a front basket is 100% accurate, as with the preceder (great term) the weight would much lower (I think the problem with a heavy frontbasket is in tilting to the side while cornering). But: lower height, more weight = same problem. – mart Nov 09 '21 at 16:25
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Most of the steering on a regular bicycle is done by tilting the bike and letting the tilt turn the front wheel, so simply attaching a two-wheeled cart to a regular fork would not work. It would also be difficult to do a more radical aftermarket addition by replacing the entire front wheel because you would need to put weight on the steering mechanism of the cart.

In conclusion, you would be looking at a replacement of the fork itself and face some challenges in keeping the cart body steady in relation to the frame, so you would probably be better off getting a purpose built cargo bike or making the modification fairly permanent.

HAEM
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    My thinking was one wheel, free to castor, for the reasons given by you. – mart Nov 07 '21 at 12:31
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    Um, that about “letting the tilt turn the front wheel” is nonsense. On the contrary, what you do is you turn the handle bars to get the bike into a tilt in the first place, and then also to turn through the corner. – leftaroundabout Nov 07 '21 at 21:34
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    Countersteering is one way to tilt into a corner, but the other is ... just leaning. In that case, shifting your centre of gravity leads and the wheel follows. They both work, but the answer isn't wrong. – Useless Nov 08 '21 at 18:08
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    @Useless You cannot really shift your center of mass on a balanced bicycle because you can't exert any lateral force. That said, in the precarious balance a bicycle presents it takes only the flap of the wing of a butterfly to begin leaning ;-). – Peter - Reinstate Monica Nov 08 '21 at 19:07
  • The way I understood it is that a bicycle stays upright is that leaning the bicycle causes the front wheel to turn to steer the bicycle back under the center of mass. – HAEM Nov 08 '21 at 20:59
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    If I can shift my weight from one foot to the other while standing up, and I can bend from the waist, it's hard to believe I'm unable to do the same on a bike. The lateral force argument only works for static objects, not flexible ones that can alter their shape at will, like us. – Useless Nov 08 '21 at 22:58
  • @leftaroundabout: So, uh… how does riding with no hands work, then? I mean, I know it works quite well, thank you, with a little practice. And in my experience, I would describe the way you steer with no hands as "weight shifting", though I suppose the exact definition of that could be argued. In any case, it does involve putting the bike into a slight lean without using the handlebars (because you're, well, not using the handlebars) and then correcting the lean once you want to stop turning. – Ilmari Karonen Nov 09 '21 at 00:00
  • @IlmariKaronen it works by giving the bike jerks with knee- and arm movements, which impart a gyroscopic force on the front wheel. That turns the steerer, and this is then what's used to control both balance and steering, just as it is when the hands are on the handlebars. – leftaroundabout Nov 09 '21 at 00:06
  • @Useless the answer is wrong. — It's true that it is possible to ride into a corner without first countersteering – it works best by stretching out a leg in the direction you want to turn, because that “pulls” the balance in that direction. (That's also how it's possible to ride over a railing that's only just wide enough for the tyre.) But the actual steering still needs to be done by turning in the fork, whether directly with the hands or through those jerky movements that allow hands-free riding. – leftaroundabout Nov 09 '21 at 00:11
  • @leftaroundabout: Um… that's definitely not my experience. Trying to make "jerky movements" when riding with no hands seems like an easy way to lose your balance and fall over. IME it's more about using your leg and back muscles to basically steer with your butt: if you want to turn left, you move your butt (and thus the saddle) left with respect to your center of gravity so that the bike leans left a bit. But not too fast or too much, or you won't be able to straighten the bike again the same way at the end of the turn. – Ilmari Karonen Nov 09 '21 at 00:27
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    (Walking a bike by holding onto the saddle works in a similar way, and is a useful skill to learn. And, unlike riding with no hands, it works at any speed since you're not relying on momentum to help you straighten out of a turn. But it definitely demonstrates that you can steer a bicycle without turning the handlebars, or without any significant gyroscopic effects.) – Ilmari Karonen Nov 09 '21 at 00:28
  • When you lean first, the fork rake turns the front wheel to bring it back under the new centre of gravity. This stops you falling over sideways, but obviously the front wheel direction can't be the reason for turning, or countersteering wouldn't work. – Useless Nov 09 '21 at 10:43
  • Commenters: it is impossible to steer a bicycle without counter-steering. You don't necessarily have to turn the handlebars yourself, but the counter-steering takes place one way or another. If you think I'm full of it, find a bike, and completely lock up the headset and try to ride. – whatsisname Nov 09 '21 at 15:54
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Even aside from bikes, i cannot think of any cargo trailer in a push setup. Not with cars, trucks or any other wheeled vehicle. The inherent problem with pushed trailers is that you always have the extra pivoting point that you´d have to control, the same one that makes reversing a car with trailer more difficult than driving forward.

The only setup that i know of with pushed cargo is a push barge where a pusher "tug" pushes loaded barges along a river. This setup is only viable because:

  1. The barges are fixed to the front of the pusher, creating a rigid setup without pivoting points
  2. A ship naturally steers from the rear. Which makes this setup similar to a rear wheel steered bakfiets ;)
MadMarky
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  • One of wheeled vehicles I could think of are forklifts. They carry their cargo in the front as well. – Alex Nov 09 '21 at 14:58
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    When you learn to ride a forklift truck they teach you to go backward in many circumstances, like when you have a big load and when you go on a road open for other users. – Willeke Nov 09 '21 at 16:08