timf
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| posted on 21/7/03 at 10:28 AM |
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suspension mounts
I'm building my wishbones with rod ends and have seen several american sites that show the bracets mounted so that the bolt passes through
vertically as opposed to horizontaly. any ideas why ?
I would of thought mounting them this way would mean that the brackets are more prone to bending etc.
Tim
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ned
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| posted on 21/7/03 at 10:55 AM |
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presumably so that the moving/pivoting part is the rose joint, as opposed to the bolt holding the rose joint!?
this is how our rosejointed suspension is on our race car
Ned.
beware, I've got yellow skin
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jcduroc
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| posted on 21/7/03 at 01:29 PM |
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Vertical axis rosejoints
quote:
Originally posted by timf
I'm building my wishbones with rod ends and have seen several american sites that show the bracets mounted so that the bolt passes through
vertically as opposed to horizontaly. any ideas why ?
Tim
Probably because the main loads on the joints come from braking and accelerating so in tension/compression; bumping and drooping loads are negligible
compared to those as they act (mainly) through the coilovers.
As far as the rosejoints can cope with the angles involved it should be ok.
Just a guess.
Joćo Matoso
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Rorty
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| posted on 22/7/03 at 05:17 AM |
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Like JC says, it's probably more for orientating the rod end to withstand the directionally greater forces, and thereby going down to the
minimum size (weight) of rod end. I presume you saw them on a circuit racer? They typically have less than 45mm of total suspension travel, so
mounting the rod ends "on their sides" will still permit enough vertical travel.
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
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timf
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| posted on 22/7/03 at 07:55 AM |
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quote:
Originally posted by Rorty
I presume you saw them on a circuit racer? They typically have less than 45mm of total suspension travel, so mounting the rod ends "on their
sides" will still permit enough vertical travel.
not a circuit racer but a locost. hence the question. i thought the joint would reach the limits of there travel with the obvious concequences.
Tim
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dozracing
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| posted on 22/7/03 at 12:36 PM |
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This is the correct way to bolt spherical joints. The reasons are two fold. Firstly they have less friction moving in that axis, and secondly the
biggest loads into the wishbone actually come from braking, and if you imagine waht braking does to the wishbone you'll see that the ball would
be pulled out in the other orientation, whereas its pulled axially in this vertical orientation. This therefore gives you longer life.
As a warning the life of these bearings is very short in comparison to bushes.
Kind regards,
Darren
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Rorty
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| posted on 23/7/03 at 05:51 AM |
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Granted, rodends suffer less friction if mounted vertically (and would be the racer's choice), but can only be achieved if travel in
either direction doesn't exceed the limit of the direction of least travel at ride height. That's why I thought you may have spotted them
on a minimal travel racer. With the travel expected from most suspensions, it's not possible to mount the rodends vertically, and they must be
rotated to the horizontal position as with most types of bushes.
ISTR, some autograssers/midgets compromised suspension travel for the greater steering angles achievable by vertically mounting the rodends (when they
didn't use TREs) on the upright ends of their wishbones.
In my off-road cars, I mount them horizontally to achieve maximum travel, but I then have to modify them on the upright ends of the wishbones to
obtain sufficient steering angles.
They'll chop up quicker when mounted vertically, as they have less support, and (most of the time) weight is placed on them axially. Less time
is spent under braking loads (though higher loads, as dozracing says).
Horses for courses. Unless you're going to spend most of your time on the track, you'd be better off with PU bushes.
If you do decide on using rodends, use the Teflon lined ones, as they're self-lubricating, and run a tad quieter. Metal to metal, be they brass
or otherwise, will chop out in a week, when fitted to suspensions. They're industrial units, not suited to the life of grit and water in
automotive service.
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
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Spyderman
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| posted on 23/7/03 at 06:21 PM |
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Syd,
I would have thought that the use of rod ends of the type you describe would not be upto the high frequency use that car suspension puts onto
joints.
The rod-ends may be massively strong and last a long time, but there is a big difference in their use. On slow moving industrial/agricultural
machinery the number of occilations would be measued in hundreds per week as opposed to thousands per day on a car suspension. (Guestimate) 
Would you be content to grease all the suspension joints every day on your car in order to drive out any grit or water?
Forget about it for a short while and you are looking for new joints!
Stick to low maintainance joints and enjoy the car more!
Lecture over!
Terry
Spyderman
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Rorty
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| posted on 24/7/03 at 07:10 AM |
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Syd, you really are a cantankerous idiot!
So what if you "have "discussed" this" before, it doesn't make you right!
You're talking massive joints on earth moving equipement (which I spent a while with in a copper mine in Zambia). Those joints see huge loads,
granted, but move so little, so infrequently, and are smothered in heavy grease to keep the abrasive grit out.
If you run a race car, there are indeed, extremely good (read expensive) metal-to-metal rod ends available. However, they don't run the cars on
a daily bassis, and usually the race teams budget to replace the rod ends on an as needs basis.
Syd, what the rest of us here are discussing, are suitable/realistic rod ends for light weight sevenesque road cars.
I'm always open to discussion, correction, and new theories, but Syd, why do you persist in continually criticising me for no obvious reason,
and persecuting me?
I have absolutely no interest in meeting up with you if you do turn up in Australia, as I do not consider you a worthy friend. So please drop it!
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
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timf
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| posted on 24/7/03 at 09:24 AM |
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Gents
It was not my intention to start a war of words between you over this question.
any one who has looked in previous posts will see that you have differing views on suspension 'joints'
could we let it go that you both have very valid points and that you disagree on the outcome.
A verbal slagging match will just detract from the usefullness of the answers supplied.
Tim
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timf
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| posted on 24/7/03 at 10:18 AM |
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opps not slagging but slanging
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