Rob Lane
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| posted on 18/10/04 at 09:21 AM |
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Tiffshaw, Bollox ! You read the thread title!!!
Post a comment about wishbone failure by all means BUT not with a manufacturers name when many other wishbones have been subject to the same failure.
A 'book' failing.
Syd
This subject has been discussed many times before and the same advice given to check wishbones based upon book design. There seems to be no reason to
mention MK as a singled out manufacturer.
Snoopy has explained the book design is flawed but the 'powers that be' in racing are always slow to react.
I don't think anyone would jump up if it was posted as just 'wishbone failure' rather than a specific manufacturer.
Incidentaly, I've had the same failure. Mine occured mid bend when suspension was under compression and hit a pothole. There was nowhere for
the resultant bottoming out loads to go but to bend the lower wishbone at the weakest point, the plate /tube junction. I'm currently making
heavier gauge oval tube design as a stronger component.
Car will 'bounce up'next time and probably pitch me sideways into hedge.
[Edited on 18/10/04 by Rob Lane]
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Peteff
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| posted on 18/10/04 at 10:01 AM |
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Fix it yourself Syd
Remove the thread. Delete the first message and start it again under locost related.
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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Syd Bridge
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| posted on 18/10/04 at 10:20 AM |
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Snoopy, from your own comments, you have been aware of this problem for some time.
Why have you not made this public, so that anybody with these wishbones on a road car, can take steps to rectify what could be a vital safety
issue?
Also, you say that you make(made) the Locost wishbones to THE BOOK design.
I've just had a copy of The Book put in front of me. This is a year 2000 issue, so the following pages may differ in other years.
On page80 is an illustration of the front suspension, showing upper and lower wishbones, and hub/upright. That picture shows a very distinct radius
on the inner edge of the coilover bracket plate, which straddles the two tubes.
A similar picture of the lower wishbone on pages 81and 82 shows the same design, with a very distinct radius to the inner edge.
Why do you say you build to The Book, when the wishbone I saw was not to this basic design?
If the wishbone I saw was to The Book design, there is every probability that it would not have failed, because the stress concentration would not be
anywhere near as severe.
Did a Qualified Structural Engineer, or design equivalent, sign off the changes?
As I'm going to get slandered by all and sundry for asking these questions, one last question. To Darren also.
Any punter walking in off the street to spend his money with you is entitled to ask for proof of your Product Liability Insurance.
Please give the name of your insurer, and the policy number. This should put you in everyones 'good books'. Because then we would all know
that you are the only two in the kit industry who carry Liability Insurance, next to one or two others who I know of.
Regards,
Syd.
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shortie
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| posted on 18/10/04 at 11:28 AM |
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Blimey, this thread seems to have got a bit out of hand!
Why don't we just leave it there and if you want to check your wishbones then do and if you don't then don't. Why bother with all
the back biting.
Probably fair to say everyone should do a quick visual check of their cars every now and again, only takes a couple of secs.
Personally I have every faith in MK and am very happy with the quality of the kit I have bought and I have also seen some of the MNR stuff and that
looks good too.
Rich.
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titch
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| posted on 18/10/04 at 11:30 AM |
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OOPPS
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Hugh Jarce
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| posted on 18/10/04 at 01:15 PM |
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This whole thread is outrageous.
The topic has been well discussed before and there are no secrets about wishbones failing.
There can be only one reason this thread was started: because one malevolent individual likes to grandstand, and even in the face of virtually
unaminous condemment, this imbecile continues to prattle on.
I can forgive any idiot, but what really grates me, is this vicivious hyena, realising his bubble has burst, starts lashing out wildly like a cornered
rat, casting aspersions on a well respected and genuinely helpful contributor and his successful business.
I have had no dealings with Darren (dozracing) but respect his extensive, unbiased knowledge and his right to better treatment on this forum.
I propose Syd be banned from this forum because of his continual foul-mouthing, cowardly attacks and general poo stirring. I for one have had enough
of him. I'm all for discourse, but only if common decency prevails.
I am going to petition Chris W to have Syd banned and I recommend others consider the same action.
The pay isn't very good , but the work's hard.
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Hugh Jarce
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| posted on 18/10/04 at 01:40 PM |
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Steve, if you read my post carefully, I'm not denying the seriousness of potentially dangerous suspension, but like many threads here,
they've been covered at least once before.
I totally respect all others' rights to voice their opinions within the realms of common decency and I wouldn't normally suggest someone
be gagged.
I'm just really mad and fed up with the cavalier way in which Syd continually pours vitriol on people and trashes their livelihoods. 
The pay isn't very good , but the work's hard.
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barrie sharp
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| posted on 18/10/04 at 03:33 PM |
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After reading all this topic has to offer my input is
Thank you for bringing this problem to my attention and i will be checking my wishbones every time i drive!!!
enough said and i dont even know who made them!!
I have read the first post a number of times and i still dont think there is any malice intended I treat it like all advice on here take it or leave
it
Barrie
the cars looking good" a blind man would be pleased to see it"
''stop press'' the blind mans seen it said "it felt ok"
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DaveFJ
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| posted on 18/10/04 at 04:19 PM |
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OOOOwwww - Matron!
now now ladies, handbags at fifty paces is it ? 
Dave
"In Support of Help the Heroes" - Always
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gazza285
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| posted on 18/10/04 at 07:21 PM |
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Obviously the bottom wishbone bolts were too tight.
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bob
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| posted on 18/10/04 at 07:35 PM |
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Like i said earlier we have been here before.
http://www.locostbuilders.co.uk/viewthread.php?tid=12587
plenty of input on this subject here.
I for one check before and a fter a run in my car,even if its a short distance.I may even make a small check list as in pre flight check,bones are
allways looked at as well as brake lines checked.I must admit to getting a bit paranoid before taking my 8 and half year old son out in it too,better
to be safe than sorry.
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marc n
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| posted on 18/10/04 at 07:44 PM |
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Unfortunately components will never last for ever, i would say four years on the same set of wishbones in racing was damn right suicidle,
I have been involved in Motoracing both as a driver and team owner for 10 years and every car i have prepared / raced and more often than not
crashed had always been subject to a lifing program to ensure safety and reliability that is why motoracing is so expensive.
top line single seater teams dismantle the cars after each race to a bare tub to inspect / xray for fractures etc and these are highly developed
machines designed and built by some of the finest engineers around !!! likewise for rally cars and topline tintop teams.
Surely if you are subjecting your car to curb hopping, ditch jumping, gravel trap skipping you expect to injuce some failures would you not ??
Rant over
regards
marc
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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undecided
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| posted on 19/10/04 at 07:42 AM |
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Mr MNR is right........only so many times a wishbone can take a thump......and as our roads are so crap they will take a pounding.
Make them stronger and in the event of a shunt they will transfer that damage to the chassis rather than confine it to a wishbone/wheel .
I
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Syd Bridge
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| posted on 19/10/04 at 08:22 AM |
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The owner of the vehicle which I saw has just emailed the following to me-
[Quote]>
The car has never been raced or tracked.
The car has never been out of my sight, it has never been curbed or suffered any form of impact.
The wishbone failed at less than 3000miles of normal road usage.
The wisbones, brakes, fasteners and joints are checked every 100 miles or so. there was NO onset of failure evident when last checked around 50 miles
previous, my technique was checking with a square edge for ant beam deformation
The suppliers DO NOT DEFINE FATIGUE LIFE FOR COMPONENTS.
As you suggested these are NOT INDY WISHBONES, but the locost type as pictured in the book which when purchased were described as suitable for my
application.
The particular design is not "detailed in the book" there is merely a picture.
[End Quote]
I put this statement on here, as these are the words of the owner of the vehicle concerned, and should answer a lot of the statements concerning how
the wishbones, and car were previously treated.
Cheers,
Syd.
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MikeRJ
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| posted on 19/10/04 at 08:27 AM |
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[Quote]>
The wisbones, brakes, fasteners and joints are checked every 100 miles or so. there was NO onset of failure evident when last checked around 50 miles
previous, my technique was checking with a square edge for ant beam deformation
Checking wishbones every 100 miles? That sounds more than paranoid IMO, has this owner suffered such failures many times before?
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David Jenkins
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| posted on 19/10/04 at 08:30 AM |
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If you want to be totally paranoid, you could paint all critical components light grey (like the old-time racers did) 'cos it's really
easy to spot cracks.
The ones that broke weren't chrome plated, were they? (reference to a previous thread! )
David
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Dave Ashurst
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| posted on 19/10/04 at 07:59 PM |
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Or you could just make them from the stuff they make black box flight recorders out of.
regards
Dave
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kipper
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| posted on 19/10/04 at 08:03 PM |
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wishbones
I hesitated to stick my twopennyworth into this thread but there is another thread running on the LOCUST SITE right now regarding wishbone tubes
cracking.
These are definitely not made to BOOK spec being replacements for cortina wishbones.
locustenthusiasts.fs.net.co.uk
Kipper.
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Syd Bridge
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| posted on 19/10/04 at 09:14 PM |
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My final words on this matter.
After another look at the book, it's the style of wishbone on page 172 which failed, at the inner joint with the plate. This is similar to the
one which was discussed a little while ago. Anyone with this style of construction, regardless of who made the things, might wish to add some extra
metal to these, to make them more like the Book items.
I am disappointed, and more than a little intrigued, that neither Snoopy nor Darren, have made any attempt to answer the simple questions I put.
Not having insurance is nothing to be ashamed of, 99% of the kit industry is with you.
Whereas, knowing of a potentially dangerous design issue, and doing little, or nothing, to let the public know; is showing little regard for those who
put their trust in you and your products.
If the industry, and the 'Lotus Seven Style' car community cannot police and rectify this situation themselves, then Big Brother will.
There are already rumblings at the VI in this direction. Woe to all, if we end up with a draconian system similar to Australia; or even worse,
Europe.
It won't be long before our cars will be failed at MOT for unsafe construction, and not just wishbones, due to new rulings which may be
introduced.
Cheers,
Syd.
For Big Bum and the couple of others who seem to have taken a dislike to anything I say: This is not a 'Dig' at anyone. I am genuinely
concerned, and disappointed, that a respected builder has chosen the path which he has. He now has the opportunity to rectify this, and I can only
hope he does so.
In the meantime, let's just hope it's not you who's invalided due to these parts.
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Mark Allanson
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| posted on 19/10/04 at 09:36 PM |
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Syd, I'm sorry that its your final word, I finally read this thread after thinking 'Oh, no not a repeat argument on the last one'
Blew the dust off my book and looked at page 172, a bit of relief that the bones were not like mine!
I am not a designer, but have many years experience as a welder and as a welder fabricator, the design on 172 is bound to have problems, as all the
forces are focused at one point, exactly where you noted the fail.
The true book design lower bones are a better design as the loads are spread over a larger area by the curve in the stress plate. I cannot believe
that the design is by Uncle Ron, as it shows a bit of understanding of how metal works.
The picture shows my wishbones and a set given to me to hold my car up until I made my own. These have been passed onto another local builder with the
same intention. These old bones passed the SVA on a car, which was later rebuilt with a new chassis and running gear(!).
Your comments would be most welcome
 
Rescued attachment Wishbone Comparason.jpg
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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MikeRJ
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| posted on 20/10/04 at 10:58 AM |
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If the wishbone was a pure triangle, the tubes would be in compression and tension only. The addition of the plate (which is obviously required for
mounting the damper) no longer makes the wishbone a pure triangle, and adds bending stresses to the two tubes.
By putting the curve in, the stiffness of the plate is essentialy graduated, and any bending stress is distributed evenly along the bend, rather than
being concentrated at one point as it is with the flat plate design.
[Edited on 20/10/04 by MikeRJ]
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Alan B
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| posted on 20/10/04 at 05:09 PM |
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quote:
Originally posted by Mark Allanson
...... I cannot believe that the design is by Uncle Ron, as it shows a bit of understanding of how metal works.....
ROTFLMAO....
Indeed, and also how metal is spec'd..see another thread somewhere else.....
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Mark Allanson
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| posted on 20/10/04 at 06:17 PM |
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Spot on Mike, That why I don't like the page 172 bones. the load path hits the tubes at damn near 90° - just asking for tears
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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MikeRJ
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| posted on 20/10/04 at 07:23 PM |
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So...hypotheticaly speaking....
If one should find oneself in the unfortunate position of owning a pair of wishbones with this less than desirable trait, would it be acceptable to
weld a second plate in (with curve cut in) behind the first and butt weld them together? My gut feeling says that the welding may add in a load more
stresses anyway, defeating the object somewhat.
[Edited on 20/10/04 by MikeRJ]
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JoelP
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| posted on 20/10/04 at 07:37 PM |
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IMHO, you could take a lower bone with the 90 degree shocker plate, and strengthen it by REMOVING some of the plate. by tapering them together, the
area will flex more and have less of a stress focus. sometimes less is more i guess...
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