Design Type

Whilst researching this project I have come to realise that the speed of change from active suspension to a locked out state is paramount to the success of my design.
At present I have a few ideas on how to achieve a rapid change but feel the need to investigate further in order to insure that my design has maximum potential.

I've used the following criteria as a guide to check the suitability of a design for the task:
1. Ease of use. Is it a seperate operation from the braking system. If so - is it redundant in an emergency situation where the brake has to be used harshly and in a rush?
2. Speed of operation. Can the design operate before the suspension has began to dip?
3. Position on bicycle. Is it likely to hinder the rider before, during and/or after operation. For example attaching a large oil reservoir to the handlebars is likely to hinder operation of other moving parts (gears etc).
4. Cost. Is it feasible to produce and sell?

Electrorheological Fluid
These are a very versatile fluid that alter their state as electrical fields are applied. When no field is applied the particles are free to float around and in this case actively work as part of the suspension. When an electrical field is applied the particles are bound together to form a solid body. This solid body would suit the purpose of locking out the suspension. This option seems perfect for the application I desire however it would require the bicycle to constantly carry a suitable electrical power supply in order to maintain successful operation. This needs to be investigated further so I will post a further blog looking at the feasability of using Electroheological fluids, which will also consider the shear stress that the newly formed solid can withstand.
A more detailked analysis of Electrorheological Fluid can be found at:
http://en.wikipedia.org/wiki/Electrorheological_fluid

Standard Brake mechanism with secondary cable operating lock out.
At present FOX (amongst other manufacturers) have a product on the market that operates the lockout from a lever suitably positioned on the handlebars (shown below).


This device works when the rider has time to operate the lever but is redundant when rapid braking is required; unless it has been left in the lock out position. I propose that it is possible to adapt this design to operate from a secondary cable that is operated by the front brake lever. The secondary cable could be suitably tensioned to allow rapid operation of the lock out device when a suitable braking force (ie large) is applied.

Bicycle position sensor.
This design would negate the need for rider operated lock out. The design would simply engage the lock out when the bicycle is positioned facing downhill. An electrical power supply would operate the lock out when instructed to do so by a position sensor. This design would also require an override function so the rider can choose to turn the system off. The design would also require operation of the front brake before it worked otherwise the front suspension would permanently be locked out when travelling down hill; which renders it useless.