To show off its new TPU filament called PRO FLEX, BigRep GmbH posted a video showing a 3D printed bike tire that uses a flexible plastic structure instead of air. The video shows them driving the bike around Berlin.
According to the company, the filament will allow the creation of a large number of industrial objects not readily built with other types of plastic. Their release claims the material has high temperature resistance, low temperature impact resistance, and is highly durable. Applications include gear knobs, door handles, skateboard wheels, and other flexible parts that need to be durable.
The material has a Shore 98 A rating. By way of comparison, a shoe heel is typically about 80 on the same scale and an automobile tire is usually around 70 or so. The hard rubber wheels you find on shopping carts are about the same hardness rating as PRO FLEX.
Obviously, a bicycle tire is going to take a big printer. BigRep is the company that makes the BigRep One which has a large build volume. Even with a wide diameter tip, though, be prepared to wait. One of their case studies is entitled, “Large Architectural Model 3D Printed in Only 11 Days.” Large, in this case, is a 1:50 scale model of a villa. Not tiny, but still.
We’ve looked at other large printers in the past including 3DMonstr, and the Gigimaker. Of course, the latest trend is printers with a practically infinite build volume.
I remember some 30 years ago having airless tyres on my push bike – holy shit were they crap – hard as rock and if it was hot day and you went to fast the tyre would separate from the rim and as long as you didnt try and go around a corner you were fine but high speed corners often met with rim on road and down I’d go.
these look like they have a bit more flex than the lumps of rubber i used to have but with the high profile Im guesing high speed cornering would be a big no no! but alright for pottering around I guess.
Yeah, I’m curious as to how the tire is staying on during a turn at a decent speed as there isn’t any air pressure pushing on the inside rim. The video is only showing straight rides.
It’s like those thousands of indian quick turnout life hacks youtube videos showing how to build tools and stuff with particle board, soda can foil and hot glue.
Yes it apparently somewhat work at some point for the video. Don’t need to work twice or not to kill you as one would expect even for Harbor Freight tools.
May have other perfectly good uses but they seem to think that the (fake) killer app of what it looks like will sell it better. May be next they could add cgi turns at speed?
someone tell me what problem this solves…?
The problem where you have a giant 3D printer at home but not a tire pump?
Selling filament.
Nice demo of what they can do, not something one would ever buy.
The video makes it look like it’s that guy’s first time on a bike or the tyres are really sketchy, poor dude looks nervous.
The flat profile must contribute to it. They could easily have given it a rounded profile, at least up to say 45 degrees, without requiring support or anything.
I bet the hardness is an issue too, but trickier to avoid. Probably slippery death traps in the wet, like those hard budget bike tyres you buy for a couple bucks at the supermarket.
Still, I’m mostly just jealous because if I had a printer like that I’d be trying it myself…
great ! had the same idea, but printing on normal printer elements to be glued… now I know it could works before to try :D
This would be nice for a stroller or kids wagon, and might print on the average printer, and with a multi head printer you could integrate the rim from abs or pla to make it more robust.
I wonder how much and when this material will be available?
I bet you make a bike tire from individual rubber links similar to a tank tread. Could be 3d printed on a smaller printer (or silicone molded) and would require one of the joints to have a tensioning mechanism. Vastly more complex than a standard bike tire though, and would probably be heavier and more wasteful of material.
This is cool, but horribly impractical. There’s a reason every vehicle in the world that uses tires uses pneumatic tires
And almost every wheel is a standard size so you can easily find replacement tires.
This might be cool for having a custom tread pattern – e.g. to prototype new ones, or for some guerilla marketing – but even still, you’d probably be better printing a tyre and putting an inner tube in it.
Actually Michelin has something just like this for cars, called the Tweel. They haven’t put them out for sale for the auto market yet but they’ve been road testing them for years and they seem to do fine.
https://en.wikipedia.org/wiki/Tweel
This needs a few more iterations before it becomes viable. I’m concerned about what happens as rocks get lodged in the holes and then the location gets stressed every time the wheel goes round. Such rocks could slowly tear the tire apart. Some kind of liner/sidewall is most likely needed needed and/or the holes need to get progressively smaller as they precede into the interior.
indeed, while considering this, my idea was actually to replace the inner tubing of a tire, so to keep the outside rubber to contact the road and protect the inside structure…
@malfist : there is a reason why all the commercial tires are not this kind: it’s a different technique from just some decade ago only, and it doesn’t wear (so bad for the commerce ;) )
it works on robots, truck, bulldozers, jeeps, and here bikes… so let’s try
I’m quite sure that the Shore rating for bicycle tires lies around 60A. Lower than car tyres anyway. I would *never* ride a bike with Shore 98A wheels! I don’t buy that video. Show the guy taking a corner at 25km/h… And then consider that professional bikeracers take corners at 70km/h. I’m Dutch… I know my bicycles and tyres… :)
But of course, this tyre could be coated with rubber (or silicone), and then it will already be a whole different story (just remember that this was my idea ;)).
Stil not the same as a proper rubber tyre with air in it, as that deforms more under weight, which increases the contact area.
Skateboard wheels are often 98A, long as the pavement is dry they grip well enough and slide when you want them to. Other than the contact patch of a bicycle being way smaller than a skateboard’s as well as rattling the teeth out of your head; what is your reasoning for not wanting to ride tyres as hard as 98a?
Well, the pavement is often not dry, and the cornering forces are different, and the speeds are different. You’re basically already “walking” on a skateboard and can just jump off if it starts skidding, but if a bike starts skidding you’re just gonna have the wheel fall out underneath you and you’re gonna have a Bad Time.
I think it might be kinda interesting, dare I say fun, if the rear wheel was a bit slippery on purpose. Drifting with a bicycle, you can’t say that wouldn’t be cool (if we were a whole lot younger)!
Just cycle on sheet ice. I’ve done it and it isn’t fun any slight turn and you are on your side and sliding, without the sheet ice you would be bloody.
About the printed tire dis-mounting in a turn?
We’re going to have match the profile of a drop center rim, to hold it better.
But that defeats the purpose of the drop center rim mounting concept…
Soooo, the Fun part will mounting any tire that is tight enough to not just roll off again.
eh, At least it could put an end to spoke trimming and rim bands.
Could be that we just need to drive in some short screws, in the style of rim locking already seen with regular rubber balloon tires.
It will be similar to this idea, But you’ll need to use machine screws. The sheet metal ones shown will NOT stay tight in something as thin as a bicycle rim.
http://ipgparts.com/blog/tech-article-how-to-install-rim-screws/
I’ve personally been seeing proof of “concept” articles for the webbed core, airless tires, since the early 1970’s. Not sure how long the idea has actually been under study though.
John Deere & Michelin have paired up with the “tweel”(trademark)
on many zero turn machines. If curious, You’ll have to parse a few professional Lawn Care sites, to find out what users think of the “tweel”.
https://www.youtube.com/watch?v=CN4AjfoiZPQ
Regarding the ridged tires that Saabman mentions, I’ve never truly understood why those are officially called “Semi-Pneumatic”
They are hollow like a plastic pipe.
I’ve never seen one that didn’t totally rely on its material rigidity for support. Nothing to do with any contained air or other gasses.
A lot of them even have open holes left from the manufacturing process.
Most push mowers have this type of tires and we just chuck the entire wheel assembly when the tread is worn out, Because of the difficulty of changing the tire
Plus no one stocks the tire, separate, anymore.
Of course the plastic wheel center usually is badly wallowed out well before then.
The ones I had were semi solid – they had like diagonal ribs inside – they were hard as hell. But I never got any punctures – lol
Does it weigh more or less than a standard inflatable tire?
Ride thru gravel and sand and get a dirt shower for blocks. This seems like it would work with the skinniest tires, maybe. I don’t ride slim tires anymore.
looks useless at reasonably any speed.. They do realise that people get on a bike to go FASTER than walking pace don’t they?
There are skinned foam inserts for bike tires. Terribly difficult to install, add some weight, more rolling resistance than air in a tube, even harder to remove when a tire is worn out – but they never go flat.
Now if they were making a 3D printed version of that, with stiffness and cell size made to come closer to a tube and air, that would be worth a look, especially for off road riding.
Filament manufacturers: We managed to print a sort-of-working bicycle tire with our filament! Neat, huh? Imagine what else you could do with it.
A million hackaday commenters: That’s a terrible bicycle tire. Also, what was that whooshing sound over my head?
This development only serves to demonstrate that it’s possible to make a bike tire that can’t go flat. I don’t think the makers are claiming that it’s better than pneumatic tires in every other aspect as well. It’s basically an experiment to prove the viability of a new filament material across a range of applications. To gain a true grasp of how well it flat-out works (sorry) as a bike tire, a number of other factors need consideration. Will there be a need for special rims? How will the tire anchor itself to the rim? Will it be easy to replace? Will the openings pack down with rocks, mud, & debris? Does it offer good traction? Is it reliable & predictable when cornering or braking? Is the price-to-feature ratio competitive in today’s (or tomorrow’s) market? These are a few questions that represent just what needs to be addressed before it can compete with dozens of other tires that already do a really great job at reasonable prices. So, this is merely a starting point. The bike parts industry is highly competitive in just about all aspects and at all price points, and new designs have to be well-proven before they can make it to the dealerships. Then again, on the other hand, there’s an old saying in the bike biz, that asserts ‘When something works too well, it has to go’. Stay tuned, folks.