What's your unsprung weight?

[Dylan]

I never seem to hear actual numbers on unsprung weight or corner weight of suspension components here, unless someone weighed their new rims before mounting them. I'm wondering if anyone has actually taken their bits off and thrown them on a scale to get an idea of the weight.

I weighed the stock Tornado front suspension corner at 44lbs. This is both A-arms, shock, and Granada spindle, caliper and rotor. The weight does not include wheel/tire. I wonder what a front corner weighs from them these days with the aluminum pieces and a better brake package?

 

[Randy V]

If you really want to learn about the effects of unsprung weight and how to know the difference between sprung and un-sprung as well as how to calculate unsprung - I would suggest you pickup a copy of Fred Puhn's "How to make your car handle". The image below was an illustration from that book.

 

[Terry Oxandale]

Embarrassingly enough...52 front corners and 90 on the rear (half of the half-shaft included). All steel, and excessive in part because of some solid pieces that allow a lot of adjustment in nailing down the final configuration.

 

[Dylan]

Hi Randy,

I actually have the book. This wasn't a very scientific approach and I had no intention of calculating it fully- I just threw it on the scale before I got rid of it.

Thanks for sharing Terry. Out of curiosity, what thickness for the tubing?

 

[Jim Cowden]

I dont think weighing all the components is a true figure.
As some components are fixed to the chassis at one end the total weight is not unsprung.
I blocked the chassis to correct height. removed the shock and spring.
I then put the scale under the wheel.
I would have to check my figures (In my laptop at work) ,I think it was about 35 kg ish on the front, 50 ish rear.
This figure includes tyre and rim and half the weight of the shock and spring.
There would be other methods but that it the one I used.

Jim

 

[Dylan]

Yes Jim, that's a good method. I wish I had gotten an actual unsprung weight front and rear before taking the original suspension apart.

 

[Bob Putnam]

The wheel, tire, hub carrier and brakes constitute the great majority of unsprung weight. Add 5Kg for the control arms and (1/2)damper/spring, and 4Kg for half the drive axle (in the rear), and you're probably within 1-2Kg. Saves a lot of work...

 

[Dave P]

Dylan you building a track car?

 

[Dylan]

Dave, as most of these builds go, I think I threw all that and the kitchen sink into the Goals bucket. Yes, I'd love to track it. With that in mind, I widened the track width and did a few other things to it that you'll hopefully see soon in the build logs.