Is bike suspension suitable for E Baja vehicle?

It’s better to use fox or Polaris suspensions designed for ATVs.

Most probably there would be a need of 6 Inch play in the wheel and considering the motion ratio of 0.6 there would be a need of 10-inch play and therefore no bikes are designed to this spring compression. You can use bike suspension like Yamaha FZ, KTM duke series, and RE Himalayan mono-shocks but that doesn’t justify the purpose of the vehicle and also bike suspension eye to eye length is very less so it would create a problem.

Fox offers a discount for Baja students in the form of sponsorship at will help teams economically as well.

Dynamic Analysis of the Transmissibility of the Rear Suspension of a Mini-Baja Vehicle

This work presents a dynamical analysis of the transmissibility of an off-road vehicle rear suspension, which was developed in CEFET-RJ for the Mini-Baja / SAE-Brazil competition. A finite element model was developed to identify the critical points of the structure. Afterwards, electric strain gages were bonded at the most critical points to measure the dynamic strains due to an impact load. Accelerometers were bonded before and after rear suspension system to measure the main transmissibility characteristics of the suspension. The data obtained through an A/D converter with instrumentation software was used to evaluate the transmissibility of the rear suspension and other important dynamic characteristics. Finally, a simple twodegree of freedom model was developed to study the behavior of the rear suspension and the influence of the main parameters in the transmissibility of accelerations and
loads to the structure. An estimate for an optimal suspension adjustment was obtained with this simple model. The results obtained with this methodology indicates that it can be used as an effective tool for the design and improvement for Mini-Baja vehicle, as the designer can work with more realistic loads.

DOWNLOAD – Dynamic Analysis of the Transmissibility of the Rear Suspension of a Mini-Baja Vehicle
SAE White Paper

How Suspension Coils / Springs are made ? Raw materials & Design Explained

I’ve noticed a lot of colleges are running air shock’s instead of coilovers, this shocked me because in a fullsize vehicle air shocks tend to over heat easily at high speeds, thus loosing their valving and tending to raise the ride height, because of this there only really recommended for rockcrawlers.

what advantages are there to running an air shock over a coilover?

First off, they weigh nearly nothing. A fox float weighs 2.1 lbs, an evol ~4 lbs. In a lightweight vehicle application like Baja, they seem to dissipate heat quickly enough to be consistent over an endurance race.

Secondly, they can be fully adjusted with a mere hand pump and a few finger twists. This is partly laziness, in that we don’t have to go out and collect all of the right springs for every occasion, but it also allows us to adjust everything within two minutes. This is quite useful when ideal suspension settings are different for maneuverability and suspension courses. We can also adjust to driver preference on the endurance race.

Finally, in the case of fox shocks at least, we don’t need external bump stops. Evols progressively increase in pressure enough to prevent bottoming out anyways.

The real disadvantage of air shocks is the cost so far. As long as you have enough air in your Floats, bottoming out willn’t appear to be a problem. In many cases your throttle might stuck right before a jump causing us to get some massive air and bottomed out the front suspension so bad that it can snap the a-arm upward.

You can also opt for Polaris OE (Fox) shocks off of the RZR . They rock, just have to get softer springs for them. Also,

Raw Materials

Steel alloys are the most commonly used spring materials. The most popular alloys include high-carbon (such as the music wire used for guitar strings), oil-tempered low-carbon, chrome silicon, chrome vanadium, and stainless steel.

High strength steels for automotive applications like suspension coil springs and engine valve springs are alloyed with high amounts of silicon because it confers increased strength and hardness (solid solution hardening), higher sag resistance (resistance to load loss, resistance to stress relaxation) and temper resistance (resistance to softening during tempering and stress relieving). Contemporary spring steels are quenched and tempered to very high strength (1900-2150 MPa, 53-57 HRC, 560-640 HV).

Other metals that are sometimes used to make springs are beryllium copper alloy, phosphor bronze, and titanium. Rubber or urethane may be used for cylindrical, non-coil springs. Ceramic material has been developed for coiled springs in very high-temperature environments. One-directional glass fiber composite materials are being tested for possible use in springs.

The Manufacturing Process

The following research papers focuses on the manufacture of steel-alloy, coiled springs for BAJA Suspension


Design and Analysis of A Suspension Coil Spring For Automotive Vehicle

Optimum Design and Material Selection of Baja Vehicle

Baja Project ‐ Suspension Design Methodoly from BAJA Tutor

Designing an Independent Rear Suspension for Baja SAE Vehicle

SAE Mini-Baja – Suspension and Frame Design

Design of Helical Coil Suspension System by Combination of Conventional Steel and Composite Material




OFF-ROAD SUSPENSION DESIGN: Ride and Handling of BAJA Buggies (Off Road Suspension Design Book 1) (English Edition)

This Book consists in a definition and analysis of BAJA suspension geometry to an off-road vehicle. The suspension selection is accomplished through the study of its geometric characteristics to design its dimensions and position of installation in the vehicle according to the expected behavior. The current suspension of the vehicle, on the front and rear axles, is analysed for understanding its dynamic behavior. The vehicle in analysis is a “Mini-Baja”, off-road prototype, which is used to run nationals competitions between engineering colleges.

After Completion of this book, you are eligible to apply for a copy of MSC ADAMS Car. The competition guidelines will be updated in the first week of April 2016.

Suspension should be designed in a way which would help in making a vehicle provide
resistance to all impact loads. The compatibility of the A-arms and 3-link suspension with the detailed parameters can produce exceptional results in the graphs of camber and caster variations , toe angles ,Ackermann geometry , proper flow of forces from chassis to ground, bump steer and shock absorber characteristics. This ensures that the off-road vehicle would improve its perceived quality of its dynamic performance and would provide good driver satisfaction in concert with excellent vehicle packaging. The same
design could be used in other off-road vehicles like Forest Rangers, Military Cars and Trucks, even in many Passenger Sports Utility Vehicles with slight variations as per the vehicle specifications and usage.





Book details

  • Format: Kindle Edition, Digital Edition
  • File Size: 6134 KB
  • Print Length: 56 pages
  • Simultaneous Device Usage: Unlimited
  • Publisher: Avinash Singh; 1 edition (7 March 2016)
  • Sold by: Amazon Digital South Asia Services, Inc.
  • Language: English
  • Text-to-Speech: Enabled
  • X-Ray:
  • Word Wise: Not Enabled

Ride rate, Roll rate calculation : Part 1

Ride rate is defined as vertical force per unit vertical displacement of the tire ground contact with respect to chasis.

Roll rate is defined as torque resisting body roll per degree of body roll.

Assumption made in calculation.

  • 0 degree camber change with ride
  • no tire lateral distortion.
  • steady state cornering ie without longitudinal acceleration.
Vehicle on Bank

1. Aα (horizontal acceleration) = V2 / Rg

V = velocity of vehicle

R = Radius of turn

2. Ay = Lateral acceleration in car axis system = Aα cos α — sin α

As FY = -Fα cos α + W sin α (from above fig)

3. Effective weight of the car due to banking is

W’ = W.Ay

4. Effective front and rear axle weight are.

W’F = W’ (b / l)

W’R = W’ (a / l)

a and b are cg location calculation for location of centre of gravity.


Part 2