Cbr 900

[sloky slocombe]

This was built for the goldrush hill climb in Queenstown originally at the moment it is getting a rear end change into something more reliable (Nissan Cefiro Cvs and axles ) did have Suzuki mini truck diff and axles and KLF quad cvs and well they just dont handle 120hp from the cbr

[freakboy]

looks good dude

[wingnut]

Very nice. Why the pushrods for the shocks? Is that to get more travel out of short shocks or just to make them progressive?

[sloky slocombe]

not sure to be honest helps with both progressive and travel altough it hasnt got much travel anyway about 300mm from full extension to compression but with droop there is only 140mm before the frame hits the ground but there is a bit extra for pot holes and the such. it was set up for gravel although it gets around the paddocks pretty good.

[diysupergokartplans]

[kazkepox]

hey man dont just be spamming your website, thats considered spam

[toystory_4wd]

That looks really seriously MEAN!!! You build that? Tell us all about the kart, more pics, too!!! *drool*

[sloky]

There more photos in my photo bucket follow the link


http://s157.photobucket.com/albums/t...0900R%20Buggy/

I will add more once im back at the shed with my camera and get it the mods being done completed.

[sloky slocombe]

There a short video of it idleing on you tube i broke it just before i could some some decent footage .

http://www.youtube.com/watch?v=3l8SKpWjY2E

[nosajwrx-7]

Shocks set up like that reduce unsprung weight.

[redsox985]

Please, this is a rather old thread, do not add comments that are otherwise unproductive to the thread. But on a lighter note, welcome to the forums. There's a great article in the Off Topic Fun section about new posters and basics of the forum. Click Here.

[Rustydog2010]

What? but the post by Nosajwrx-7 is some what productive, as if you refer to post#3 it ask why use a rush rod system and was not answered, i didn't know and would have liked to know and Nosajwrx-7 answered it. And you wonder why people post once and then leave. And anyway if something is wrong isn't that moderators are for?

[redsox985]

Post #3 was also nearly 3 months old. If he truly wanted the answer, the poster would have bumped this thread asking for an answer to his question. Am I wrong? When is the last time we've heard from wingnut?

[modelengineer]

Shocks set up like that reduce unsprung weight.

No, they don't. They actually increase unsprung weight, they are used for better aerodynamics, another way to adjust ride height, and to corner weight the car, as well as change the ratio of wheel movement to shock movement.

It increases unsprung weight as you now not only have half the shock unsprung (as before) but you also have the added unsprung weight of the pushrod, and bellcrank. Anything which moves with the wheel, and not the chassis, is unsprung weight so this includes the pushrod and bellcrank.

[Rustydog2010]

Originally Posted by redsox985

Post #3 was also nearly 3 months old. If he truly wanted the answer, the poster would have bumped this thread asking for an answer to his question. Am I wrong? When is the last time we've heard from wingnut?

Yea but if Sloky had bumped the thread asking for the answer would you have snapped at him? He would still be bumping a 3 month old thread, wouldn't he? Exactly what wrx-7 did...

@Model Engineer

Cheers, that makes more sense lol

[fowler]

i didnt see this thead 3 months ago and i have seen this setup many times and i cant find info telling me why

thanks modelengineer

[nosajwrx-7]

The shocks in the picture are fully supported on the frame not the suspension. The push rods are half supported on the suspension and half on the frame, and push on the coilovers. They are not unsprung weight. But ohwell.

[fowler]

gonna say, i agree with Nosa but the first paragraph of models makes sense

[modelengineer]

The shocks in the picture are fully supported on the frame not the suspension. The push rods are half supported on the suspension and half on the frame, and push on the coilovers. They are not unsprung weight. But ohwell.

If the shocks were "fully supported by the frame" then they wouldn't move with the suspension. They wouldn't do anything.

Seriously, think about it for a bit. ANYTHING WHICH MOVES WITH THE SUSPENSION IS UNSPRUNG WEIGHT Does the shock move? Yes (half of it, anyway). Does the pushrod move? Yes. Does the bell crank move? Yes. The hub? The wishbones? Wheels and discs, etc? Yep, all unsprung weight.

I should clarify that it IS possible to reduce unsprung weight this way if your shock is very heavy at one end. If a normal setup would mean the heavy end has to go on the swingarm, and a pushrod setup means the heavy end is mounted to the chassis, then that could reduce unsprung weight.

I can give an example. If you have a pushrod system, with a shock that weighs 500kg, do you think it would cycle very well? The shock has a huge amount of mass which needs to be moved for the suspension to go up and down even though it's actuating through a pushrod. It's all unsprung weight.

I think the reason most people get confused is that the actual weight force (due to gravity) of the shock is (mostly) supported by the frame. Perhaps a better term for unsprung weight is unsprung mass. Either way, they both mean the mass which has to be accelerated for the suspension to move.

I hope this clears things up.

[theo]

I think that shocks, a arms and any part of the suspension that is attached to the frame are only partially classified as unsprung, not sure of the percentage. So maybe anything past the shock pushrod is mostly classified as sprung weight.