"Car and truck tires need tread, because these vehicles are prone to a very dangerous condition called "hydroplaning. At high speeds, hydroplaning is just possible for car tires, but is absolutely impossible for bicycle tires."
(Bicycle tires can't hydroplane, at least not at bicycle speed, and therefore road bike tires don't have treads. Treads reduce the contact area between the tire and the road, resulting in worse traction than a perfectly smooth tire.)
Treads are usually for harsh environments: hard rain, ice, mud, to increase traction and avoid hydroplaning.
In regular environments (see: driving on paved road) they actively work against speed by reducing road contact due to tread gaps. That's why racing vehicles use smooth wheels:
Plus most cars were still using slick (smooth) tires up until around the 1940s-1960s and (I don't believe) were fast enough to have a threat of hydroplaning.
ETA: Just remembered you were talking about the bike. Considering the background, it looks like it was used on dirt roads so if ever mud happened to be in the way, one could just carry the bike over. Dirt roads also don't usually require too much turning and are fairly sturdy, so there's little reason to believe skidding was a common problem.
Even if it were for sidewalk/road riding, you can easily get out of the way of puddles and slow down easier than cars.
I used to think that the treads actually ruin the road because it changes to contact surface on which you apply the power differential from a line (on a tire) to a rectangle(the tread), i.e. it tries to rotate a flat surface which can't be rotated, so somethings got to give. Arguably a tire wouldn't have the same problem.
Friction motors are not great in the rain. The tire tread type and width, the pressure on the tire and the material of the friction drive surface are all difficult to get right. These kinds of motors are very noisy too.
Tire tread is kind of a dangerous measure; you don’t necessarily want everyone switching to a super hard tire. Basically you can trade tread wear for stopping distance.
Do they? Tires only have significant contact area because they deform. I would expect that with the right air pressure, these would match the contact area.
I’m more concerned about the fact that the tires have no actual tread, which means they’re going to be unusable in the rain. Of course this whole thing makes no sense so none of this matters.
> The [forklift] tires often dont even need to be removed, as they have more treads that can be created by pulling out zip-tie like spacers in the worn tread
Wow, that's clever. But it does make me ask, tread is AFAUI for dealing with water on the ground, and I guess also when the vehicle's going at speed.
Forklifts AFAIK operate mainly indoors, and even then they never get up to any speed that I've ever seen, so why treads at all?
Love the comment about water evacuation through holes reducing hydroplaning.
I'd love to know what's holding these back. Perhaps it's just a higher cost:MTBF ratio, and one day it will surpass regular tyres. Perhaps they're really truly better, but pneumatic tyres are just Good Enough. Perhaps there's a fundamental flaw in the idea that only experts can see. Probably we'll never know.
> Tread doesn't do anything for traction and just makes you bury your tires faster.
Large textured tread is primarily about mud. When the size of the "lug" is large enough, it ejects the mud up & back, leaving the tread free to grip again. Without these, in the mud your tires become big smooth balloons with no grip.
Big tires are primarily about climbing obstacles. Loose sand rarely is a tall obstacle ;-)
One advantage large tires can have in the sand is that when you air them down, the surface area gets much larger, and that can keep you "afloat" on top of the sand better.
I wonder if there are low noise tire tread designs? Of course there are probably trade offs. Snow tires are known to be louder than the tires you use in climates that don’t get snow.
Because treads are worse than tires for compaction overall. As a soils expert explained to me (phd in the subject), compaction is a function of weight, but the function is something like 0.2*(weight) (obviously it is more complex than that and depends on the exact soil type). Compaction happens only where the tires/treads touch the ground, and tracks touch a lot more ground when you turn so even though there is less damage across the field you lose all of that and more when you turn around. Not to mention tracks have to slide sideways to turn and that is bad for your topsoil.
For examples, studded snow tires can tear up the road surface quite significantly, tend to kick up a lot of sharp fine dust. It's such a big problem they're often banned parts of the year in some regions where they're typically used.
It seems to largely suggest that GP is correct (see the figure in 5.3.8 for example), with the caveat that this is mainly a problem in colder regions of the world.
http://www.sheldonbrown.com/tires.html
"Car and truck tires need tread, because these vehicles are prone to a very dangerous condition called "hydroplaning. At high speeds, hydroplaning is just possible for car tires, but is absolutely impossible for bicycle tires."
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