
which is better and why
This has been argued thoroughly in the past.
Summarizing what I've read on threads in the forum:
If you mean on the top & bottom of uprights then rose joints will, it appears break in the end where as ball joints won't.
Have a search on the Running Gear forum for the subject.
If it were a race car though I'd used rose joints everywhere.
Both are a threaded bar and a spherical joint. I don't see why one would break and the other not if you used the same size. Obviously an M10
rod end wouldn't be as strong as an M14 ball joint.
Ball joints are designed for the job though and often have tapers and things for direct mounting.
If you spend the same money on a rod end as you'd spend on a production ball joint, the production part will very likely be a higher quality
part.
Balljoints are internaly lubricated, sealed, and pre-loaded to ensure a long working life. Rod ends have no seals as standard (though are available)
and have no spring pre-load so any wear at all will introduce lost movement. On the plus side the lack of the pre-load means rod ends have much less
friction which can improve steering feedback etc.
so ball joints for long life and rose joints for best feel and for the lower joint try and get the best quality and as big as possible
Sorry to break into this,
Is it not that balljoints are designed to handle forces from more directions?
If not then i'm happy and wil use rose-joints
Ps. I will use them nevertheless 
[Edited on 22/12/06 by t.j.]
I used ball joints at the bottom (as they support all most all of the front end weight, and take the most pounding) and rose joints at the top. Gives
the best of both worlds - strength, plus feel.

Balljoints main advantage is they can pivot further than a rod end. Often rod ends are maxed out and as soon as that happens they break. Balljoint
also tend to have more surface area to transfer impacts. For longer life the balljoint also has a pre-load spring to suck up any play. In a high
load,high dirt, high impact and high frequency situation (like on a car) the balljoint will always outlast the rose joint.
IMO the rose joints are fine for steering, and the upper pivot (if the upper is the unloaded pivot). I like sealed balljoints for lower pivots
though. If you drive your car on dirty roads, and run it hard on the track don't expect more than 1-3 seasons out of the rose joints. One more
note, always use safety washer with rose joints if they are mounted in single shear. Other wise if/when it breaks the eye can come off the pivot and
your steering/suspension link is no longer linked 
quote:
Originally posted by C10CoryM
One more note, always use safety washer with rose joints if they are mounted in single shear. Other wise if/when it breaks the eye can come off the pivot and your steering/suspension link is no longer linked![]()
the washer is big enough that, should the ball pop out of its housing, the washer holds it on long enough for you to stop! Obviously if the housing
breaks its all gone tits up. 
Couple pictures here.
http://www.hmsausa.com/news/releases/lotus_2.html
Cheers.
quote:
Originally posted by JoelP
the washer is big enough that, should the ball pop out of its housing, the washer holds it on long enough for you to stop! Obviously if the housing breaks its all gone tits up.![]()