Weight per axle

More
11 Dec 2013 07:52 - 11 Dec 2013 08:00 #615270 by Patton
Replied by Patton on topic Weight per axle
Will float this theory -- which may be seriously flawed -- for locating the center of gravity.



Could use a plum-bob from front axle to rear axle to help attain perpendicular position of the suspended bike.

Other factors also influence the center of gravity by varying weight locations, such as fuel volume, aftermarket components (eg., various exhaust systems, luggage racks), etc.

The H-D Buell is well-known for it's low center of gravity
As are BMW boxer twins, and Roly-Poly toys.

Good Fortune! :)

1973 Z1
KZ900 LTD
Attachments:
Last edit: 11 Dec 2013 08:00 by Patton.

Please Log in or Create an account to join the conversation.

More
11 Dec 2013 10:34 - 11 Dec 2013 10:35 #615289 by steell
Replied by steell on topic Weight per axle
Weight times arm = moment. So create a reference datum and weigh the front and rear wheels.
That will give you longitudinal CG, I don't have a clue how you would calculate vertical CG.

If you fly an airplane, you need to know how to calculate CG.

And I don't think any bike has a lower CG than a Gold Wing, it almost stands by itself.

KD9JUR
Last edit: 11 Dec 2013 10:35 by steell.

Please Log in or Create an account to join the conversation.

  • DOHC
  • Offline
  • Sustaining Member
  • Those Doe-Hawks really go!
More
11 Dec 2013 21:18 - 11 Dec 2013 21:21 #615326 by DOHC
Replied by DOHC on topic Weight per axle

peavylotus wrote: I found a worksheet PDF that has equations for calculating dynamical and statical load,


You really should just go buy a digital bathroom scale that can report up to 400 lbs. Amazon has them for $15. Then you can work with real numbers.

On the other hand, you could just assume the vertical center of mass was in line with the crankshaft. I broke down a junk yard engine and I was amazed that the crank alone was almost 50 lbs. ~10% of the total bike weight.

Also, I'm not sure if you noticed, but the manual that has the front/rear weights also gives numbers for stopping distance. It would be interesting to see how your calculations compare with the numbers Kawasaki claimed:

'77 KZ1000-A1: 11m from 50 kph
'78 Z1R: 12.5m from 50 kph

See what those fancy dual drilled rotors buys you? Negative 1.5m.

'78 Z1-R in blue , '78 Z1-R in black, '78 Z1-R in pieces
My dad's '74 Z1
'00 ZRX1100
Last edit: 11 Dec 2013 21:21 by DOHC.

Please Log in or Create an account to join the conversation.

Powered by Kunena Forum