Author Topic: Physics smarties, apply within  (Read 375 times)

0 Members and 1 Guest are viewing this topic.

DaleCooper

  • Trade Count: (0)
  • Jr. Member
  • **
  • Posts: 55
  • Rep: 4
Physics smarties, apply within
« on: October 08, 2020, 07:27:58 PM »
53mm og formula 99D with reds
56mm F4 99D with bones big balls

I understand that smaller wheels have better acceleration but lower top speed output at the same RPM as a big wheel. And big wheels have higher top speed output at the same RPM.
However, I hopped on my 53's yesterday and that thing goes waaaay faster than my 56's.

So does this boil down to bearings? And just as well, does that fact about the same RPM hardly apply to us as skaters at the lower speeds we're at? (Minus the SF guys)

johnes

  • Trade Count: (0)
  • SLAP Pal
  • ******
  • Posts: 4168
  • Rep: -237
Re: Physics smarties, apply within
« Reply #1 on: October 09, 2020, 06:54:08 AM »
Small wheels like 51 and under always feel much slower than 54s for me with same brand bearings (MiniLogo) in them.
I’m a fat Siamese cat.

Skrotum

  • Trade Count: (0)
  • Jr. Member
  • **
  • Posts: 95
  • Rep: 12
Re: Physics smarties, apply within
« Reply #2 on: October 09, 2020, 07:13:32 AM »
I think friction from a larger contact patch might be adding to that difference in decrase in acceleration and increase in top speed, are they both the same shape?
But my best guess is that it is a combination of the big balls with the bigger wheels giving you that noticeable slight slower acceleration.
Hopefully someone will crunch the number im interested to see the exact difference in a perfect scenario.

baustin

  • Trade Count: (+2)
  • Hero Member
  • *****
  • Posts: 605
  • Rep: 115
Re: Physics smarties, apply within
« Reply #3 on: October 09, 2020, 07:46:50 AM »
There are way too many variables at play to break this down on a physics level with 100% certainty. My best guess is you felt the smaller wheels accelerate faster and therefore it felt faster to you.

DaleCooper

  • Trade Count: (0)
  • Jr. Member
  • **
  • Posts: 55
  • Rep: 4
Re: Physics smarties, apply within
« Reply #4 on: October 09, 2020, 08:37:07 AM »
I think friction from a larger contact patch might be adding to that difference in decrase in acceleration and increase in top speed, are they both the same shape?
But my best guess is that it is a combination of the big balls with the bigger wheels giving you that noticeable slight slower acceleration.
Hopefully someone will crunch the number im interested to see the exact difference in a perfect scenario.

The 53's are the OG classic
The 56's are full conicals
Contact patch is a good point for sure. Top speed is definitely higher on the 53's and that's the one thing I didn't account for.

CannerSpaghetti

  • Guest
Re: Physics smarties, apply within
« Reply #5 on: October 09, 2020, 09:47:16 AM »
Fasted wheels I've skated were Spit F4 Classic shape 53mm fresh out of the wrapper. Coming off some flatspotted mini-logo wheels that were like 48mm, I put my board down, took one push, and almost fucking slipped out cuz they just went that fast.