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Efficiency of pneumatic tires vs Flywheels


#1

I’m thinking of getting one of the forthcoming single motor Trampa Urban Carvers with 7 inch pneumatic tires. I am now getting nearly 12 miles range with 75 millimeter Flywheels and a 12S 5Ah lipo setup. What kind of range could I expect with the Trampa, with the same batteries?


#2

Probably 75 to 85% efficiency


#3

I get quite a bit more than half (maybe 70%), but I keep my 8in tires at 80psi (Ground Industries MAK wheels)


#4

My 6" pneumatics roll nearly as well as all of the big squishy abecs and Kegels.

probably 75-80% efficiency


#5

I feel like I barely get as much range as I should be with 10s8p

Though I am using basically huge bike chain and pneumatics lol


#6

Thanks for your thoughts, gents. FWIW, I spoke to Ted @trampa and he said the tires (http://www.trampaboards.com/innova-inline-street-tyres--7-inch-tyre-p-12772.html) may be run at 75 psi, which should help.


#7

with my 5inch skike wheels I get like 50℅ of the range with the kegels. Pressure is 6.3bar.


#8

you can see the difference well in the range specs of the evolve. its seems to be about 60% range with at compared to longboard wheels.


#9

What is the main cause of the reduced efficiency? Is it the increased rotational mass of the larger wheels? Increased rolling resistance of pneumatics? Less efficient drive system from chains/wider belts? Higher gear reductions? I’d guess the extra overall weight of the board could factor in too, but that seems like it would have a minimal impact. I wonder if there is some ideal setup/combination of components that would maximize efficiency and range.


#10

the entire benefit of having pneumatics is the softer ride. That is due to the wheel “absorbing” shocks caused by stuff on the road. The way it does this is by transforming flexing energy in heat - and that is where the decreased efficiency comes from. This is also the reason why harder wheels give better range but ultimatively you need to find a balance between comfort and efficiency. Nobody will want to ride on wheels made out of metal I think :wink:


#11

The shock absorbent and larger diameter should increase efficiency, because such wheel will lose less speed when it encounters a small bump in the road.


#12

larger diameter yeah - shock absorbing no. Just read up on hysteresis:
http://www.atbsshow.com/rollingresistance


#13

So you are right that the rubbery compound of the pneumatic wheels is making it less efficient, but notice that shock absorbent is not mentioned here. generally speaking shock absorbent is not necessarily equal to soft wheels (for example piston shock, though it’s not relevant here).


#14

I respectively disagree. You might be in the group that doesn’t want to pay for billet pneumatics, but if you rode a set you’d realize how wrong you are about them.


#15

What? I was talking about wheels made out of solid steel - no rubber or air anywhere. Think train wheels!


I guess you did not understand my post.


#16

Ahh my bad…For the record, one of my first skateboards did have metal wheels (with no rubber). :joy: