At Hunter, we want to start engaging with the community at an earlier stage of the development process to get your feedback and learn what you’d like to see.
With that said, could you help us create a better esk8 tire?
So our priorities are:
Low rolling resistance and low weight as we want to keep our board as light as possible and with as much range as possible.
Now what are we trying:
1- Wide tire to keep rolling resistance low.
2- No tube to keep a low profile and to use as less rubber as possible.
3- aluminum wheel to keep the wheel as light as possible.
Now the reason for each point:
1- Rolling resistance comes from tire hysteresis, the compound plays a huge part in this energy loss but geometry does too. The more a tire deforms the more it loses energy. To counteract this we are doing a wide tire. For the same mass(rider+skate weight), there is more area distributing that force, which results in a smaller tension. Tension is proportional to extension (deformation) so a wider tire will lose less energy to hysteresis.
2- Air doesn’t waste energy like rubber when compressed so the more air you have and the less rubber the lower the rolling resistance, because of that we are thinking of eliminating the inside tube and keep a low profile. What do you guys think of that?
3- Well this one is easier, aluminum has a better mechanical resistance per kg than plastic and it is easier to work then carbon fiber, not only that but contrary to carbon fiber it has the same resistance in all directions.
In the end, we want to create a 5in tire that can compete in efficiency with a poliurethane tire will improving the comfort and being much lighter. (don’t know if it is possible)
many in this community have dreamed of this, and if anyone could pull it off, it would be you guys
Huh, I always thought that a narrower tire → higher air pressure → less rolling resistance, but from reading online it seems like that’s true only in a lab environment, and that in real life a wider, softer tire with less pressure actually wins. Cool!
when you look at competitive cycling, you’ll see that the tires are super narrow and high pressure for the minimum rolling resistance. i think a wider contact patch giving less resistance due to deformation is only true in urethane wheels.
So what you say in point 1 is true, less deformation = less resistance, but i don’t necesarily think a wider tire will aid in this.
what material do you want to make the wheel out of? rubber or urethane?
So from what I gathered it is true for every tire. The problem is that a rolling cylinder is really bad in terms of aerodynamics. So for speeds higher than 40-50 kmh the gains you get from rolling resistance are completely eliminated by the aerodynamic drag.
We are using rubber just because it is what the tire manufactures gave us an option. I would love to see a urethane tire but I don’t think that is possible due to the steel mesh. But I have to ask the manufacturers.
we just need wide square-profile tubeless tires with efficient rain grooves for daily urban use. not too big of diameter (125-175mm) and with a good rubber formula that’ll help avoid flats.
Isn’t this the opposite of conventional logic? Most efficiency oriented cars have as thin of a tire as they can go to reduce rolling resistance (same with those world record solar cars, they’ve basically got bike tires). I would expect that to translate in esk8 as well.
Another further upside to narrow tires is higher ground pressure, which means you can even run slicks in the rain. From Schwalbe:
Unlike a car, a bicycle will not aquaplane . The contact area is much smaller and the contact pressure is much higher. The floating effect of aquaplaning could only theoretically be achieved on a bicycle ridden at speeds over 200 km/h. On a normal, smooth road, even in wet conditions, a slick tire actually provides better grip than a tire with a tread, because the contact area is larger.
Thank you I really hope we can get a decent range on pneumatics.
We had a lot of work done with the urethane. A good urethane doubles your range, even with the same hardness.
I think we have to compare tires with the same air pressure because you can always put more pressure on a wider tire too. The thing is more contact area means less tension, less tension means less extension and less wasted energy.
The problem with big tires is aerodynamic, which I don’t think is such a great problem for esk8 velocities.
Well it is all about speed.
You have rolling resistance and aerodynamic drag. For speeds higher than 40-50kmh (or even less on cars) the aerodynamic drag outweights the rolling resistance by much. A rolling cylinder is really bad in terms of aerodynamics and that is why you want to keep tires as thin as possible.
For rolling resistance it is the opposite, more area means less tension because tension = F/A, which means less extension, which means less energy wasted.
The other thing is the tire form. Knobies will waste a lot more energy. So that was what I wanted to know too. What do you guys think of wide slick tires for esk8?
I believe the people who like to race buy exclusively that kind of tires Would definitely be a hit. Just need to make the hub bearings off-centered for people with short axles.
Would definitely be a hit. Just need to make the hub bearings off-centered for people with short axles.