3 vs 4 Wheel Task 2

Article review https://engineerdog.com/2015/09/09/engineering-a-3-wheel-vehicle-chassis/

Stability

Delta

• Weight distribution very particular, advantages and disadvantages to both

  • Too much front weight increases risk of tipping

  • Too much rear weight increases risk of oversteering

• Tends to have rear biased weight distribution, better for breaking in straight line

  • a hard enough stop transfers weight to front and flips car

Tadpole

• more stable while driving, don’t need to be as peculiar with weight distribution

• more stable when breaking

Winner: TADPOLE

Breaking

Delta

• less area to break on

• less stable

Tadpole

• more breaking area

• more stable

Winner: TADPOLE

Design Simplicity

Delta

• only accounts for one wheel

• don’t have to consider steering types

  • Ackermann, etc

• Suspension also simpler due to one front wheel

  • Can have positive caster

Tadpole

• Multiple styles of suspension available

• Harder to design steering

Winner: DELTA

Aerodynamics

Delta

• Doesn’t fit as well into typical aerodynamic teardrop shape

• More empty space in aerobody

Tadpole

• Almost perfectly fits into teardrop shape

Winner: TADPOLE

Powertrain

Delta

• Going with front wheel drive means more front weight means less stable

• Must make sure steering mechanism doesn’t interfere with engine

• Rear wheel drive requires the incorporation of a differential to be stable

Tadpole

• Best with rear wheel drive

  • No differential needed

  • Centralize CG more on drive wheel

  • No interference with steering

Winner: TADPOLE

Conclusion

• Tadpole takes 4 of 5 categories described in this article

• Tadpole is generally the best for vehicles; however, delta has value in certain applications like tricycles