Performance advantages of FF's

Performance Advantages of FF Single Track vehicles

Definition; “FF”

A single track vehicle with a seat base less than 20” above ground level at ride height, fitted with a seat back capable of supporting the rider. The front suspension should not be steered.


The following applies to all FFs and is a comparison with motorcycles.


This was developed to explain the performance of the Quasar in 1978, and elaborated after testing and development of the Banana in 1981. It closely resembles the “Technical Advantages” chapter in the FF Information Pack that I published in 1986. The major advantages can be confirmed using basic geometry (A compass, a ruler) and all are supported by experience with a number of subsequent FF designs.

Familiarity with Newtons three laws of motion is necessary.

The major advantages are as follows;-

1. The FF layout substantially lowers the Centre of Gravity (CG) of the vehicle and it's rider/s.

This eliminates excessive or intrusive weight transfer during braking and acceleration. Weight transfer is proportional to the height of the CG.

It allows direction changes to be made faster and with less effort - The CG moves through an arc as the bike banks from side to side. The higher the CG the longer the arc and the greater the effort required to move the CG through the arc in a given time.

It reduces the unloading of wheels during fast direction changes - the arc has a vertical component, rising and falling as the bike banks. The higher the CG the greater the vertical movement. If the CG is high, enough upward momentum may be given to the CG by a fast direction change to lift the rider out of the seat and the wheels off the ground.

It permits better suspension and less ground clearance, due to the lack of excessive weight transfer.

2. The FF layout provides the rider/s with a secure and comfortable seat.

This prevents entirely accidents where the rider falls off a motorcycle.

It provides a secure platform for rapid and precise control corrections - The riders hands do not support the rider who can thus operate the controls without fear of losing balance.

Comfort is sufficient to eliminate fatigue and cockpit heating is easy to arrange.

3. The front suspension is ideally derived from automotive systems, like the Difazio/Tait/Creasey "Double Wishbone" systems, where the suspension is not steered. This reduces the rotational inertia of the steering and increases it's stiffness, eliminating steering wobbles and complementing the fast and precise steering movements made possible by the secure seat.

Double wishbone systems separate braking, steering and suspension effects

These advantages allow an FF to be controlled faster, with less effort and greater precision than a motorcycle. The absence of wobbles or wheel lifting and the ability to brake while steering, considerably extends the control envelope.

The are a number of other benefits that flow from the FF layout;-

The frontal area of an FF is smaller than that of a motorcycle, making it more fuel efficient.

The layout allows a better basic shape with low drag and good stability. This can be enhanced using extensive bodywork without losing other qualities.

Bodywork, coupled with the comfort and heating already noted, can provide weather protection at least as good as open topped cars. Outdoor clothing is normally sufficient for FF users.

The basic riding position, suitable bodywork and appropriate detailing can provide much better crash protection than other two-wheelers. This adds to the excellent agility and controllability to provide a major safety improvement over motorcycles. This has been demonstrated in several real accidents.

The low seat allows a very wide range of users to fit the vehicle and the low CG makes low speed handling and control easy.

The structural requirements are simpler than those of a motorcycle with a steering head and no new technology is needed to make this vehicle type.


FFs can accelerate, brake and turn harder and faster than motorcycles. They are easier to drive, more comfortable, warmer, drier and more fuel efficient. They make it easier to avoid accidents and offer more protection if one happens. They are accessible to users and easy to make.

Royce Creasey
April. 2008
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