Uncovering the Physics of MotoGP's Knee Slider Technique

  • Context: High School 
  • Thread starter Thread starter asdfqwe123
  • Start date Start date
Click For Summary

Discussion Overview

The discussion revolves around the physics of the knee slider technique used by MotoGP riders during turns. Participants explore the implications of modifying knee sliders by adding wheels to reduce friction and enhance lean angles, while also considering the stability and safety aspects of such modifications.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant proposes the idea of adding a small wheel to knee sliders to reduce friction and allow for greater lean angles.
  • Another participant counters that knee pucks are already made of low-friction plastic, suggesting that the friction force would not decrease significantly with added wheels.
  • A different viewpoint highlights the potential instability introduced by a wheel if it is not aligned with the direction of travel, which could lead to accidents.
  • Concerns are raised about the practicality of using wheels, including the possibility of them jamming on small obstacles.
  • One participant mentions the importance of the knee in judging lean angles and providing stability during emergencies, rather than primarily supporting the bike's weight.
  • There is a suggestion that regulations may restrict modifications to the knee sliders, such as adding wheels.

Areas of Agreement / Disagreement

Participants express differing opinions on the feasibility and safety of adding wheels to knee sliders, with no consensus reached on the proposed modification or its implications.

Contextual Notes

Participants discuss the role of knee sliders in terms of friction, stability, and regulatory considerations, but do not resolve the technical aspects of the proposed modifications or their potential effects on performance.

asdfqwe123
Messages
1
Reaction score
0
Hi :)
I have a question or maybe something more like a mind puzzle (at least for me :))
The drivers of MotoGP touch the ground with their knees while turning. For this purpuse they wear knee sliders made of rubber.
Now I was thinking how it would work if they added a small wheel to the knee sliders. This way there would be less friction and they could lean more.
Or am I wrong? Can somebody explain the physics behind this dragging your knee on the ground?
 
Physics news on Phys.org
asdfqwe123 said:
Hi :)
I have a question or maybe something more like a mind puzzle (at least for me :))
The drivers of MotoGP touch the ground with their knees while turning. For this purpuse they wear knee sliders made of rubber.
Now I was thinking how it would work if they added a small wheel to the knee sliders. This way there would be less friction and they could lean more.
Or am I wrong? Can somebody explain the physics behind this dragging your knee on the ground?
Welcome to the PF.

The knee pucks are made of low-friction plastic, so you will not decrease the friction force much below what it is now. Riders mainly use the pucks as "feelers" to help them stabilize their lean angle.
 
besides that, a wheel has a preferred direction of travel. Suppose the riders knee touched down and the wheel was not pointed exactly parallel to the direction of travel. This could easily throw the rider off balance and cause an accident. An answer to this could be to use casters or spherical rollers, ,but then you'd still have the problem of the wheels jamming on small pebbles. Ever been pushing a shopping cart through a parking lot when one of the wheels suddenly stopped turning because a tiny rock which acted like a wheel chock?
 
I don't think you want to put weight on the knee (or any wheel mounted on it) if that results in less weight on the driving wheel?

I suspect there might also be something in the rules about motor bikes only having two wheels.
 
As I understand it they use the knee for two main reasons:

1) to help judge the lean angle and
2) in emergency when the bike starts to slide.

It's not normally used to keep the bike up.
 
  • Like
Likes   Reactions: berkeman

Similar threads

Undergrad Wheel physics -- which scooter would be easiest to get to school and back?
  • · Replies 25 ·
Replies
25
Views
5K
Undergrad Speedway Motorcycle Racing Physics
  • · Replies 3 ·
Replies
3
Views
5K
High School How Does Blackbird Leverage Wind Power to Move Faster Than the Wind?
  • · Replies 69 ·
3
Replies
69
Views
16K
Admissions Statement of purpose critique request (high-energy theory PhD)
  • · Replies 6 ·
Replies
6
Views
3K
Graduate Hardest physics question/task. No naysayers please Thanks
  • · Replies 11 ·
Replies
11
Views
3K
Physics Is returning to school sensible for me?
  • · Replies 33 ·
2
Replies
33
Views
5K
Undergrad Debunking the Myth of the Devil's Racetrack in Death Valley
  • · Replies 9 ·
Replies
9
Views
3K
Newtonian physics word problem static friction
  • · Replies 15 ·
Replies
15
Views
4K
Where to "restart" my math education
  • · Replies 3 ·
Replies
3
Views
3K
Real-World Collision Investigation Project for High School Physics Students
  • · Replies 2 ·
Replies
2
Views
3K