Trike Centre of gravity position (longitudinal and vertical)

[sophtayl]

Hi All,

a question that maybe some builders / others who have gone through the process can assist with.

To have a trike registered in Aus, we need to conform to the relevent ADRs (Australian Design Rules).

One of particular importance is the stability assessment. refer to link below, section 21, along with figures 3, 4 and 5 further on.

ComLaw Legislative Instrument Compilations - Attachment -

A pdf version is available from here
ComLaw Legislative Instrument Compilations - Vehicle Standard (Australian Design Rule 42/04 - General Safety Requirements) 2005 (ADR 42/04)

Now for my question.....

I am working through the design and component selection process and need to identifiy the typical CoG height and longitudinal position along the bike.

As the ADR states, the Height of the COG shall be no great than the perpendicular distance from the COG to the nearest Roll axis. The nearest roll axis is the line drawn between the rear wheel track and the front wheel as per figure 5.

The relationship of this to the rear axle width is significant. I am wanting to limit the width of the trike to a 46" track, but need to confirm this isnt going to create an unregisterable vehicle.

Alternatively, if someone has gone through the process of identifying the Balance Angle as per figure 4, that would be extremely helpful.

I will be triking a Harley, but any info will give some guidance.

Any thoughts, suggestions also welcome.

Kind regards

Mick

 

[FBTRIKE]

Re: Trike Centre of gravity position (longitudinal and vertical)

Guday mate.........I know this post is old, butI can't sleep and this is interesting stuff..
Boy, what you have to go through down there to ride on three.......
Have you had any luck getting that COG point on your HD?
I would love to watch you guys balance that bike on its rear wheel.

If you haven't got it yet let me know. Seeing as I have an06 Fatboy that I have triked and it doesn't have fenders on it. I might be able to ge a few friends and stand her up.. and get that COG for ya.......My rear axle is 46" wide.

Let me know.......

 

[fatchina]

Re: Trike Centre of gravity position (longitudinal and vertical)

Now for my question.....
I am working through the design and component selection process and need to identifiy the typical CoG height and longitudinal position along the bike.

As the ADR states, the Height of the COG shall be no great than the perpendicular distance from the COG to the nearest Roll axis. The nearest roll axis is the line drawn between the rear wheel track and the front wheel as per figure 5.

The relationship of this to the rear axle width is significant. I am wanting to limit the width of the trike to a 46" track, but need to confirm this isnt going to create an unregisterable vehicle.

Alternatively, if someone has gone through the process of identifying the Balance Angle as per figure 4, that would be extremely helpful.

I will be triking a Harley, but any info will give some guidance.
Any thoughts, suggestions also welcome.
Kind regards

Mick

Hi Mick,
Have you had a look at this document?
http://www.infrastructure.gov.au/roads/vehicle_regulation/bulletin/pdf/NCOP15_Trike_Guidelines_3Feb2006.pdf

it has all the measurements etc for determinig the CoG - I haven't used it yet, stumbled on your post whilst looking for the same sort of info!!

Cheers,
Steve.