Gyroscopic forces in motorbikes.

  • Context: Undergrad 
  • Thread starter Thread starter Foss
  • Start date Start date
  • Tags Tags
    Forces
Click For Summary
SUMMARY

The discussion centers on the impact of gyroscopic forces on motorbike handling, specifically comparing the 2010 KTM 400EXC and 450EXC models. The 400EXC features a reduced engine displacement from 449.3cc to 393.4cc, achieved by shortening the stroke from 63.4mm to 55.5mm. Participants debate whether this reduction significantly affects handling by diminishing gyroscopic forces or if it merely alters the power output, making the bike more manageable. The consensus suggests that the centrally located engine in a single-cylinder configuration likely minimizes the effect on lean rates.

PREREQUISITES
  • Understanding of gyroscopic effects in physics
  • Familiarity with motorcycle engine specifications
  • Knowledge of motorcycle handling dynamics
  • Basic principles of torque and power output in engines
NEXT STEPS
  • Research the effects of gyroscopic forces on motorcycle stability
  • Explore the engineering differences between single-cylinder and multi-cylinder engines
  • Investigate how engine displacement affects motorcycle handling
  • Learn about motorcycle suspension systems and their interaction with gyroscopic forces
USEFUL FOR

Motorcycle engineers, enthusiasts, and riders interested in understanding the dynamics of motorcycle handling and the influence of engine design on performance.

Foss
Messages
1
Reaction score
0
Just a quick problem for you guys that goes a little bit further than my high school physics education.

In recent years dirt bike manufactures have been trying to negate the effects that the crankshaft, through gyroscopic effect has over the motorbike. To take one example; the 2010 KTM 400exc. This bike is exactly the same as the 450exc apart from the engine. They have reduced the displacement from 449.3 to 393.4. They have done this by reducing the stroke of the engine.

They have reduced the stroke (and therefore the diameter of the crank) from 63.4mm to 55.5mm. Now my question is would this have a large impact on the bikes handling through reducing the gyroscopic forces or would it be a perceptive effect by reducing and changing the power output of the engine and making it more ‘manageable’.
I know that to figure out this properly you would need more weights and measurements but I don’t have access to them. I have tried but not luck. Any light that you guys could shed on this topic would be GREATLY appreciated.


MK
 
Physics news on Phys.org
Considering the engine is centrally located near the roll axis of the bike and rider, and that it is a 400cc single cylnder engine, I doubt it would have much effect on the rate of lean on a dirt bike.
 
Last edited:

Similar threads

  • · Replies 19 ·
Replies
19
Views
3K
  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 23 ·
Replies
23
Views
4K
  • · Replies 10 ·
Replies
10
Views
5K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K