Wednesday, 28 Jun 2017
 
 
Prototype (Represents development stage 1 of 6)
Prototype
Prototype’s purpose 
The sole purpose of the prototype is to demonstrate the 4MC's fundamental design principle of four wheels via four transversely pivoted suspension arms. To achieve this it was not necessary to equip the prototype with mudguards, lights, or bodywork.

Prototype’s adjustable features 
The prototype includes many adjustable features that a production model would not need. For example, rake/trail, steering offset, Ackermann steering differential, toe in/out, front/rear brake force differential, remote suspension damper housings to aid damper adjustment.

Other features on the prototype 
To be able to see the front suspension working, the fuel tank was positioned between the back wheels. On a production 4MC the exhaust could be positioned between the back wheels with the fuel tank conventionally placed in front of the rider.

Prototype’s limitations 
(i) The 4MC’s leading and trailing suspension arms are ideally suited to being bolted directly to the engine/transmission unit. However, the prototype’s 400cc engine was not designed to have suspension arms bolted to it. Therefore, the prototype had to have a separate frame which weighs 67kg and raises the prototype’s centre of gravity.

(ii) The prototype’s separate frame required the front suspension to be mounted a lot higher than necessary. This also raises the prototype’s centre of gravity.

(iii) The space needed for the prototype’s adjustable rake/trail has made the prototype’s wheelbase a little longer than required by a production 4MC.

(iv) The prototype’s 400cc engine/transmission includes a reduction gearbox which would not be needed on a production 4MC. The reduction gearbox has made the prototype’s wheelbase a lot longer than a production 4MC would require.

Final remarks about the prototype 
The prototype works extremely well despite its above limitations and the very small budget from which it was created. It is exciting to imagine just how good development stage six (4MC's last development stage) could be with Kickstarter funding, click here to find out more about the 4MC's Kickstarter campaign.