Caster can technically be decribed as the angular displacement of the steering axis from the vertical axis. For our purposes though, it affects the amount of self centering and steering “feel” or our vehicles.

Speed and Self Centering

Consider these two bikes. The cruiser has a greater caster angle which gives it better self centering which will feel more stable and heavier for the rider.

The race rep has a lesser caster angle which, to the rider will be easier to turn and more agile as any required steering effort will be less.

Steering Feel

If you want the ultimate fast reacting steering then why not set the caster angle to 0? As you reduce the caster angle, you will also reduce the steering “feel” meaning the driver will feel more removed from the action.

Conclusion

I set my caster angle to about 2 degrees as I prefer fast reacting, effortless steering. However, it is very subjective so give room for adjustment when desgning suspension and remember the following:

Is your stearing too heavy?

Reduce the caster angle

Does your steering feel numb?

Increase the caster angle