# Wheel physics -- which scooter would be easiest to get to school and back?

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Greggl4321
I've got a physics question. I've been looking at scooters, one of them is light weight with a 98mm wheel, and several others are heavier with bigger wheels. I'm having a hard time phrasing my question, but what I'm wanting to know is what benefits are there too the bigger tired scooters?

They can roll over rocks better, so less friction/drag (not sure if these terms are used interchangeably)

But they are heavier, therefore, its going to take my thrust to get the scooter going.

How can I determine which scooter would be easiest to get to school and back?

Bigger tire seems to be less friction
and also less thrust

Would it be better to have a lighter scooter that I could get more thrust out of, or a heavier scooter that has less drag/friction?

How do I even bigger to compare and contrast?

At a certain point, bigger tires add weight and make a short trip long.

Greggl4321
Question is what is the best scooter?

Light weight with a small tire, or heavier with a bigger tire? ;)

My intuition is telling me the lighter scooter with the smaller tire is better than the bigger wheeled heavier scooter.

I'm thinking that the light weight scooter trumps the less friction/drag scooter.
Whatever energy is lost through friction/drag is easily recompensed by additional kicking. (Lighter scooter)

berkeman
Mentor
Welcome to the PF.

Is your route to school flat or does it have some hills in it? Is it all on asphalt or concrete, or is there some dirt/grass involved?

Greggl4321
Bigger tires = less rolling resistance,

This doesn't necessarily mean bigger tires equate to less resistance, or na easier journey for lack of better terms, because they add weight.

At what point does the weight from the bigger tire start to slow you down

berkeman
Mentor
Bigger tires = less rolling resistance,
Only on rough ground. For dirt and uneven surfaces, you want a little larger (and fatter) tire with some compliance. For smooth pavement, you can go with smaller/lighter tires that are very hard -- that's how you lower rolling resistance.

Greggl4321
I believe the problem remains conflated.

On my way to school I encounter hills, asphalt of varying poor condition, and sidewalk.

Why do you want some compliance for ruffed ground? (Im thinking okd asphalt that hasnt been repaved in a while that always has industrial trucks running down it with cracks in it ect)
There is a pneumatic wheeled scooter vs hard urethane, yet its been in my mind that these tires would be slower and have more resistance.

Where does it say bigger tires reduce rolling resistance only for smooth surfaces?

I think the problem is still unsolved, can additional people please chime in? Thanks for the response.

berkeman
Mentor
For smooth surfaces, hard tires minimize rolling resistance (picture Rollerblade wheels).

For surfaces with sketchy traction, larger and wider and softer tires improve traction at the expense of higher rolling resistance (think motocross tires).

For rolling over obstacles, larger wheels work better (at the expense of higher moment of inertia and weight).

Do your friends have any scooters you can borrow for a day each to try them out on your trip to school? You may be able to fine-tune your choice with just some practical experimenting on the actual route.

Greggl4321
Still cinfused, this is what ive been trying to get at
Is the bigger tire and its lower rolling resistance going to slow me down because of the added weight?

berkeman
Mentor
Bigger/wider tires do have more weight and a higher moment of inertia (so harder to get rolling or change speeds). That's why road bicycles use skinny 100psi+ tires, and mountain bikes use wider tires at around 35psi.

You should probably only use tires/wheels that are big enough around to get over the cracks and bumps without too much discomfort, and use the hardest tires you can without making them dangerous when traction goes down briefly (like hitting dirt patches on the street or sidewalk).

Can you post pictures of some of the scooters and tires you are considering?

Greggl4321
I'm unable to upload photos at the moment,

The scooters are the A6, and A4 from razor.

I currently own the A6, have owned the A5, and am now curious about the A4.

Another question is they say the A6 was designed for "taller riders", can someone explain what was designed on the scooter for taller riders?

berkeman
Mentor
Greggl4321
Yikes, I am filling a bit foolish. I can not recall why I got the bigger one, I liked the previous model a lot but wasn't thinking about the weight.

Yikes

So the smaller scooter will slow down quicker without kicking and will be more dangerous? I'm 6ft, 220lbs, what's the best scooter?

Someone mentioned that the bigger scooter would be better for distances, not sure why that is.

Another question is they say the A6 was designed for "taller riders", can someone explain what was designed on the scooter for taller riders?
Larger wheels adds more stability, and longer handlebars for more comfortable posture... I'm 6'1" and riding shorter, smaller wheeled scooters gets uncomfortable really quick.

I liked the previous model a lot but wasn't thinking about the weight.
More weight takes more energy to get it moving but it also coasts further per push...

The weights of the A4 and A6 are 3.4 kg and 5.0 kg. When you compare it to your own weight however, that difference isn't significant. The difference in wheel weight is even less significant. For riding experience I would pretty much always take the A6. I think the smaller wheels of the A4 would be very uncomfortable on sidewalks or bicycle paths with tiles, or streets with bricks wich are common in the Netherlands. The only reason to choose the A4 would be the price or if you have to fold it up and take it with you inside.

Greggl4321
I fell today. I've noticed at times I lose traction. I don't think it was like this on the A5, why would that be?

Greggl4321
I'm particularly losing traction around turns, why would this be?

I'm particularly losing traction around turns, why would this be?
Tires are too hard to maintain grip and lack of suspension makes bumps particularly dangerous.

Greggl4321
Are the tires of the a6 harder than the a5 ? Cause the a5 didn't slide

Greggl4321
No, I had the a5 lux, it didn't seem to lose traction like the a6 does.

Not quite sure that this was answered, but which scooter is easiest to push back n forth from school? It'd be the a4 right? Since its the lightest? Can someone elaborate as to which scooter they think would be best?

Not quite sure that this was answered, but which scooter is easiest to push back n forth from school?
For overall efficiency the lightest is best if you're zig-zagging low speed with little straightaways, and something with meat and a motor and batteries and torque on your traction wheel guided by your air filled, low rolling resistance, recharge braking/ inertial absorption system would be optimal for every advantage.

Greggl4321
Even on straightaways it would be more efficient too though right?

was thinking this was the case, wasn't sure if I came to the realization on my own or through the article. I've (I think) decided to just push the bigger one, might get stronger. (or maybe I'd get stronger pushing lighter weight more often?)

Also, I'm wondering this.

Is losing a few pounds the same as the scooter being a few pounds less? (I'm not thinking so)

Is the weight on each wheel balanced?

What'd cause the A6, with bigger wheels, to lose traction -- unlike the A5 lux.
I notice that the diagonal piece is much longer on the A6, not sure what that'd affect. Also, the axels are much higher, not sure if that gives a higher center of gravity, or puts more torque on the wheel when going diagonally.

Hope razor isn't out to get me now

Would they be?

I had some more written but I lost it.

I feel foolish for not getting the A4,

I just

Thank you all

Greggl4321
Which scooter out of all of razors scooters do you think would be best ?

The a4? Or something earlier

Would the 143 recommended weight limit be too little for 200lbs to 220 lbs? Or would I be OK?

Greggl4321
The person who reviewed the a5 said a kick would push him further on the a5 then on the scooter with the 100/110mm wheel (razor A4)

How could this be? I thought people are saying the contrary is true?