Digger Barnes
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 posted on 19/1/04 at 08:51 AM |
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Rose Jointed suspension
Now here is one that ma be more hassle than it is worth.
I will hopefully starting building my wish bones in about 2-3 weeks and I am just starting to look at a few options.
What I was considering whilst reading the book on the bog yesterday was instead of using metalistic or poly bushes to use rose joints instead.
I thought that the advantage would be, it would make the suspension geometry easily adjustable.
Now I know that there would be some draw backs as well, harsh ride etc. I am not to worried about that though as I will mainly want the car for track
days.
But now to the real point, is this madness and what rose joints would take that sort of abuse?
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Findlay234
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| posted on 19/1/04 at 09:21 AM |
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Well i think that you really did cover the main points about rose joints yourself. More easily adjusted, will give better handling(less sloppyness in
the suspension) but a harsher ride. I think rose joints are designed to take the battering that racing gives.
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Julian B
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| posted on 19/1/04 at 09:35 AM |
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If you were thinking of doing a lot of competition diving then go for rose joints, but i think unless your use to driving a suspensionless mini or
the like, you will soon get tired with the harshness of the ride. The added cost of rose joints/end bearings is also a big minus.
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Digger Barnes
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| posted on 19/1/04 at 10:16 AM |
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I am used to a harsh ride on my current motor. seriously buggered about with suspension i.e. not a lot of suspension. Round town it is hell but with a
bit of speed on dual carriage way then it is fine.
I know the rose joints will be even harsher.
So does anyone know off hand what spec rose joints to go for and a good shall we say inexpensive supplier.
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stephen_gusterson
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| posted on 19/1/04 at 10:32 AM |
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i used rose joints all round
it would have been faster and cheaper to have used bushes, than give max 'adjustability' as I did
rose joints in side loaded mode are rated approx 15% of their full rating. I used 16mm joints to be anywhere near comfortable, these were 16 quid each
and there are 12 on the car!
side loading will occor on front wishbones during braking.
you dont want them popping out the shank.
there is a huge difference in spec of types on the market. cheap one have 50% of the rating of rae ones (about 38 quid each) and 70% of mid range
ones.
dont go cheap- and be sure of the load rating and that the place you are putting them wont cause them to fail.
I have heard of 10mm joints being used on the rear trail arms, but i wouldnt fancy that
atb
steve
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Digger Barnes
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| posted on 19/1/04 at 10:42 AM |
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If I do go down the rose jointed route then there may even be a few more than that on my car as I want to use pushrods on the front suspension to a
rising rate linkage so that I have absolute control on how the suspension responds.
mmm I shall have to have a look to see if there are any suppliers that we use that stock the things so that I can get a company discount.
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Peteff
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| posted on 19/1/04 at 11:00 AM |
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I used 12mm on the axle end of my trailing arms and panhard rod to give a bit of adjustability. I will do the same again next time as well, no
problems. I used standard brackets and spacers to hold them in place as I had already welded the brackets on. If I needed to I could go back to
ordinary bushes this way.
yours, Pete.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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Digger Barnes
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| posted on 19/1/04 at 11:25 AM |
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So the consensus is that there are no major issues with rose joints then.
Great that is one less thing to think about.
Cheers folks you have put my mind at ease.
Although I am sure that when it comes to building the suspension set up then I may well have a few more questions to ask
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RPS
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| posted on 19/1/04 at 12:39 PM |
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I do not know if others have tried this web site before (I haven't done so myself), but there is some useful info' on sizes, dimensions,
max load etc..
http://www.autosport-bearings.co.uk/webshop/home2.jsp
RPS
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Digger Barnes
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| posted on 19/1/04 at 01:06 PM |
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Interesting, they do seem to be a bit pricey though
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craig1410
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| posted on 19/1/04 at 01:23 PM |
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Hi,
I've used them on the rear of my car for trailing links and panhard rod and they seem fine. I've not got my car on the road yet but they
were easy to work with and are very compact. As well as load ratings make sure that the maximum angle of misalignment is suitable for your
application. This is basically how far the bearing can articulate before it binds with the body of the rod end. Side loading is an issue but it should
be possible to design your chassis and suspension to minimise or eliminate any side loads.
I used 1/2" rod-ends for my application and these have more than enough capacity for handling any theoretical acceleration, braking and
cornering forces that I can foresee. Even then the rod-ends I have selected are only being stressed to 10% of their maximum load. They only cost me
about £8ea from rally design.
Cheers,
Craig.
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Digger Barnes
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| posted on 19/1/04 at 01:30 PM |
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Ah that seems more like it.
I think I shall work out which rod ends I require. Then I will try one of our suppliers at work to see if I can get a good discount. Many of the
companies we deal with give us discounts of any where between 10% and 50% off list.
IF I can get them alot cheaper would any one be interested?
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stephen_gusterson
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| posted on 19/1/04 at 02:24 PM |
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comparing two ypes of 16mm, one had a 16kN loading for 16 quid, other was over 70kN at 65 quid!
atb
steve
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MikeP
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| posted on 19/1/04 at 03:13 PM |
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We've just had a discussion on the North American Locost list (yahoo, aka one of TOLs) about a problem with a broken rear suspension bracket.
There's pictures of one that failed in the photo section of that list, rose joints were used on the trailing arms. Conclusion was that if you
use rose joints, it would be better to use a narrower and/or better secured bracket for safety.
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Digger Barnes
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| posted on 19/1/04 at 04:04 PM |
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Cheers for the tip. Although I won't be using trailing arms, as I am going down the IRS route. That is one of the reasons why I want to use rose
joints, so that I can fine tune the suspension.
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locoboy
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| posted on 19/1/04 at 04:28 PM |
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Juat a quicky Digger,
Try a search, there was a post on here a month ago or so by Rorty mentioning the type of washers to be used when using Sperical bearings/rose
joints.
Well worth a read and makes sense too, not something i would have thought about but i will be implementing it when the time comes.
ATB
Locoboy
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stephen_gusterson
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| posted on 19/1/04 at 04:50 PM |
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basically, as the TOL thing inferrs, you need to have something either side of the suspension rose joint in case the bearing pops out under sideways
loading. Rorty suggests substantial (3mm ?) thick 'washers' to kep the rose body captive if it pops.
on my car, I made my brackets out of square section 2 ins tubing. if the joint pops, it will rattle around about 30mm inside the bracket housing. wont
exactly be fab handing, but the wheel will stay on!
atb
steve
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dblissett
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| posted on 19/1/04 at 08:13 PM |
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rose joints
i have gone for rose joints from skf the ptfe lined one are weaker so i went for the one with the highest load ratings from skf its the one with
bronze inserts
mine are m14 i have only used them at the upright ends of my wishbones and i am ussing rubber bushes at the chassis end i hope this will give me
adjustment but also damp down some of the harshness
anyone have any thoughts if this is right
cheers dave
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Rorty
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| posted on 20/1/04 at 03:39 AM |
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Yes, I seem to remember posting a pic of the safety washers too.
In my book, the bronze lined rod ends are for industrial use, where they can be kept oiled.
PTFE (Teflon is one brand) lined rod ends are the best solution for road and track use, if you must use rod ends. They are available in just about any
strength you could possibly require for a Locost. They also don't require lubrication, and in fact, are not resistant to some lubes. Anyway,
lube attracts road dirt (read: grinding paste). The PTFE actually acts like a wiper to keep the ball spotlessly clean.
Unless you're an out-and-out racer, who likes spending hours setting up regularly, I would stick with PU bushes. They're easier to set up
and maintain, and you'll hate the rod ends (even the slightly more forgiving PTFE lined ones) if you drive on the roads.
People kid themselves about the amount of adjusting they're going to be doing.
If it were me, I would fit PU bushes for road and track. They're the perfect compromise.
(Isn't that a contradiction in terms?)
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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Digger Barnes
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| posted on 20/1/04 at 08:12 PM |
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cheers guys
The safety washers look like a good idea. I think I will turn a few up.
By the way the main aim for this car will be to start with a few track days to iron out any problems, followed by hopefully entering the 750 motor
club RGB class C racing series.
Plus I would not mind scaring the cr@p out of a few of the lads with the odd spin out.
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dblissett
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| posted on 20/1/04 at 08:26 PM |
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i think you should check the regs just to make sure rose joints are allowed
i dont think they are allowed in all the classes
good luck dave
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Digger Barnes
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| posted on 20/1/04 at 08:41 PM |
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I read the regs I while ago and in the deep mists of my mind I seem to remember that suspension is free in that class.
One of the reasons that I chose that classis that it has tight regs on the engine, but still room to be a little different in the chassis design and
suspension setup.
P.S now you mention it though I will go back and have another read as it is getting a little hazy now
[Edited on 20/1/04 by Digger Barnes]
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Jon Ison
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| posted on 21/1/04 at 07:10 PM |
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Rose joints no prob in all RGB class's,
will u b out this season ?
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Digger Barnes
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| posted on 22/1/04 at 08:31 AM |
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I would like to think that I will be ready for the end of this season, but more likely it will be next season.
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Jon Ison
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| posted on 22/1/04 at 06:10 PM |
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gis a shout if i "can" be of any help, racin class A this season.
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