Do you think the early wishbone can actually 'flex' to a position of negative camber? By 'flex', I mean elastic deformation. Can it 'flex' to a negative camber situation and then relax back to it's original shape with no permanent, or 'plastic' deformation when the load is removed? Or do you believe it is just a matter of it being a weaker structure which can be bent more easily, but if bent to the point you have negative caster, permanent deformation will have occurred?
Yes. No. Yes. Maybe.
Hal,my theory is the tube ends are just fine,but over the 100 years,corrosion on the inside and out of the tube has weakened them They will certainly not snap back into their original position. Add the many loose nuts in the equation,and it is what it is..
Gary, You seem to be flexing quite a bit on this subject.
Let me put it this way....Say there was a car that had been wrecked but the camber after the accident seemed to be OK. Do you believe the wreck could have been caused by a negative camber situation that was only temporary while a load was being applied, and sprung back to its original position when the load was removed?
Are you guys referring to camber or caster. I don't see any relationship of camber to the wishbone.
The wishbone has nothing to do with camber.
I agree with Jack. I think when it's bent, it's bent.
Its right here in black and white... ws
If a nut is loose at the perch, it would be much easier for the wishbone to flex into negative caster, or so it's be reported here.
The bad thing is....I know the difference and still screwed it up.....
I thought it was caster but you can never be too sure with everyone using the same term.
Steel does have elasticity and the rods can flex and change the caster then return. If the rods flex enough to reach the bending moment, they will remain bent and the caster will remain MORE negative. The caster is already negative in the design of the perches.
Love the humor Troop!!!
I take that back. The caster is upside down so bent rods would make the caster LESS. Sorry.
I don't think that flex, in the truest sense as wishbone flex has anything to do with it.
Just talking through my butt and owning an 'over the top' and several later 'under the bottoms'...my '15 is what I consider 'tight' yet if any one of mine is going to misbehave in reverse...it's that one!
Logical conclusion only, but that said and knowing it is as tight as I know how to make it including how the wishbone ball seats, my guess is that the front with an 'over the top' has a different 'spring constant' and is easier to 'flex' as an axle system within it self. Certainly in Reverse, and just maybe going forward as the reasons would be the same I imagine.
Drop that support at the spindles by about 3" and all of the force 'reaction moments' in engineering-speak when taken about the front spring mounting move to different places...better places. My '15 doesn't get used as much any more as the stable grew with others and the '15 is/was a near pure to begin with. It definately isn't my highway cruiser as it goes to 45-50+ when I'm not looking and doesn't even breathe hard...where the Hack and the Fordor start wheezing well before 40! But I have already decided long ago on my own and on a just because basis that should the '15 start to come out more...its' getting a sympathetic double wishbone arrangement!
I subscribe to the Daron Theorem. Who knows how thin the tubing has become underneath that show quality paint.
While an accessory brace is probably the best situation, try finding and using one of the very last of the early types. Look for the Ford script as a starting point. These last ones had heavier tubing.
As an experiment, what I'm going to try is to salvage the forgings from an original and re-tube it with thicker walled steel. It's a lot of monkeying around but I'd like to give it a shot. If it comes out well I will change out the one on my own '14.
"I don't think that flex, in the truest sense as wishbone flex has anything to do with it."
Me either. I was just curious what others thought.
Somebody should take one that's already bent, and see how much it flexes.
To answer your question, yes, the caster can go negative, cause trouble, then return to "normal" after the dust clears.
In the case that I was personally involved in, the perches were worn severely in the holes where the wishbone ends fit. Just sitting still, everything looked fine. When driving and making a slow left turn, the front wheels suddenly flipped hard to the extreme left and had me pointed at a parked car. Since I was test driving the car for buddy who just bought it, I was ready for anything and quickly horsed the wheels back straight. Quite a lesson! When I got it parked again, everything looked fine. I grabbed the axle with a pipe wrench as twisted it ahead, creating negative caster. It was shockingly easy and the wishbone didn't so much flex, in the way that you would expect, as it did twist, with the wishbone ends slightly rotating in the perch holes.
It turned out the wishbone was actually in excellent condition but the holes in the perches were hugely worn oversize. I suppose someone in the past "fixed" the situation by just tightening the nuts, which of course fixes nothing.
After installing new-old-stock perches and a lower brace, it's now rock solid and safe.
Please people, ADD THE LOWER BRACE.
Thanks, Jerry. That's just what I was trying to say.
That's nonsense. In good shape there's no way a wishbone can flex to negative camber and then magically flex back to normal. You guys have taken too much medication.....or something.
If your Model T is covered with worn out / maladjusted / loose / broken parts you need to fix that. You don't have to convert every Model T into a later model to make it safe and reliable.
When turning onto full lock in my car, you can feel a point at which the side pressure on the tyres pulls the axle back and the wheel pulls itself onto full-lock. So the answer is Yes, it goes negative and back to its normal position when you straighten up.
I won't be putting a brace on my car. I had a low-speed, non-injury accident 2 years ago which bent the wishbone like a banana. (It did not cause the accident - that was me, the driver.) That wishbone acted like a crumple-zone and absorbed the force of the impact. With a brace, the force would have been transmitted into the pan and caused who-knows-what damage to the pan or frame.
Instead of worrying about the wishbone failing, you should be worrying about the steering box. We have seen a number of accidents reported here with bent wishbones and people assume that was the cause. I believe the steering ratio is to blame; 1 & 1/4 turns lock to lock with a small steering wheel gives all the mechanical advantage to the front wheels.
Jack up your front end. Get a volunteer to push sideways on the front tyre while you hold the steering wheel. Don't get your muscle-bound football player son to do it, get your timid maiden aunt, you will find the frailest of ladies will be able to rip that steering wheel from your hands with a one-handed push on the tyre. If you hit a pothole or kerb with the wheels on partial lock, you will not have the strength to stop that wheel whipping round to full lock.
What we need is a steering box with a sensible ratio that can discreetly slot in at the bottom of the column instead of the normal bracket, hooking up to the standard steering links. RDR has used a V8 box, but it's a bit too obtrusive for a my taste.
Have you proven your statement by testing, Royce?
Do as Jerry, and put a long pipe wench to the front axle of each of your cars, and see how many degrees you can tilt the axle.
I'm not so sure that what Jem is describing is caused by negative caster. If I'm understanding it correctly, it sounds like the 'over center' steering situation we hear about from time to time.
With a loose wishbone or loose spring perches, I can believe you might get negative caster without bending the wishbone, but for a good fitting wishbone and good perches with everything tight like it's supposed to be, I find it hard to believe a wishbone can flex enough to give negative caster and not have any lasting effects on its shape.
Kinda OT, but something else to consider. If you approach an abrupt, steep incline, your caster can be negative. What is the caster? 5 degrees? What if you hit an abrupt incline that is greater than 5 degrees? Say your front wheels are on the incline but the rear has not yet hit it. I experienced this while loading my TT on my trailer. Someone had parked behind my trailer and left me very little room to load. I hit the ramps at somewhat of an angle and had to turn the wheel hard to get lined up. When I thought I needed to straighten up, the steering wheel tried to go all the way to the other side. I can only assume it was because the ramps are at probably a 20 degree angle. That would give about 15 degrees of negative caster.
I think you meant negative CASTER in all references in your post even though you mentioned camber in a few places.
Having just straightened up a badly bent early wishbone off a nice original 1914 touring car I can only say that the wishbone like other pieces of steel on Ford's T model requires you to push the metal well beyond just "straight" in order to remove a curvature and make the item straight. Thus it really depends on where you start from with regard to whether you could get all the way to negative caster or not by simply hitting a bump which was not hard enough to permanently bend the wishbone. In the case of the wishbone I straightened the axle too was badly bent but the whole thing happened because a newbie drove the T off the front of an open flat bed trailer and the axle and wishbone dropped down a good distance to then land on the tongue and hitch. The axle was fully in negative caster land since the top of the axle was well forward of the bottom. When I first saw the car I thought the axle had been assembled backwards since the fellow was new to T's although the car itself had been in his family a long time. I cannot say that a proper straight early wishbone with a proper straight axle and a set of correct spring perches and everything correct could then flex into the Negative Caster region just by hitting a bump but I doubt it since if that were possible then they whole front end design would have been tossed very early since roads were way worse then than now. I can tell you that there are not many NOS early wishbones around and I think most of us just check the caster and see if the top of the spindles are back at least 1/4" from the bottom and assume all is OK if they are and the rest of the front end is tight. My son has a 1916 roadster with all parts being straight front end but we also have an accessory angle iron brace on it. I don't think the brace is as safe as the single under axle wishbone because the bending of the later front end gives more positive caster while the accessory brace on an early front axle attempts to prevent the axle from going negative but has no ability by itself to overcome the upper wishbone and add positive caster. I think that in a frontal collision it would be better if positive caster were added rather than negative if anything got bent enough to change the caster. It would seem that the front wheels are the most likely thing to hit something first and with the later wishbone - that would add positive caster and with the early wishbone that would add negative caster and with an accessory braced early wishbone it really is hard to say for sure what would happen but it would seem that since there is more total bracing that the front end would tend to not change caster. It would seem most prudent to add a brace that is stronger than the upper wishbone so as to err on the side of adding positive caster. Lots of testing would need to be done to prove out any of our opinions here.
Right. Henry insisted Frank Kulick drive faster than is prudent in a Model T. Then an inevitable accident resulted from travelling at idiotic speed for the road conditions. It wasn't caused by the wishbone.
Cut the BS.
"...for a good fitting wishbone and good perches with everything tight like it's supposed to be, I find it hard to believe a wishbone can flex enough to give negative caster and not have any lasting effects on its shape."
I tend to agree with you here. The question is, how many cars are being driven that have excellent parts with little or no wear? How many owners would even know? By example, the car that I test drove, above, was purchased from a guy who owned it 5 years and drove it regularly. Among other comments, he stated that everything was fine and it drove and steered well. Of course, he could be fibbing but, having spoken with him personally, I found him to be very honest in everything else stated about the car, both good and bad. In fact, he went out of his way to point out other problems just so we would be aware and not disappointed. I really believe he just had no idea how a T was supposed to drive and handle.
To Royce, I know your cars would be meticulously maintained and as safe as a T could be. But being realistic, I also know that's not the case with every T out there. Let's be honest, we've all seen cars on tour that we've had our concerns over. I would rather see braced front axles on more cars than need them over seeing just one more wrecked T or injured occupant. (again, not referring to the Utah car since we don't have all the facts)
I am really trying not be an alarmist, or to over react, or to scare anyone. I am simply recognizing that the early front ends can be problematic and that not all T owners have the depth of knowledge or experience to realize what's at issue, to spot the signs of trouble or to correct it. A lot of owners would never know they have a problem until that problem became an "incident".
Well said Jerry. Before we got into T's we looked at a (1998/99 timeframe) 12 speedster. I do remember (now) it had the early style wishbone but we were ignorant. Had the purchase been finalized we would have been driving unaware. You aren't being alarmist but a realist. Know what you've got and be sure it's "right"
Royce, I remember reading one of your posts once about how one of your early wishbones snapped while driving 35mph. What caused that to happen?
A long, long, LONG, time ago, I learned a lesson the hard way. I used to ride a bicycle a lot. And I used to have to run to the gas station occasionally to get a gallon of gasoline. I had this nice old bicycle, except that at some point, the front fender bracket broke. So I decided it was easier to just take the fender off than fix it. I had, before the fender broke, always hung the gasoline can on the handlebars, knowing that the fender would prevent it from hitting the front tire. Now, I always had an engineer's mind, and I always considered safety. So I very carefully checked the way the can hung on the handlebars. I checked every angle, bounced it, jumped on it, figured any way I could how close the gas can could get to the tire. There was no way the can could hit the tire, by almost an inch. So off I went. Riding down the street. Hands in my pockets. Gas can hanging on the handlebars. When the bicycle flipped a full somersault and landed on the ground past where I lay looking up at the sky.
I didn't know how. Some way, that can had hit the front tire and jammed the front tire so that the whole thing flipped all the way over. I rechecked the can and the handlebars and the front forks and there was NO way it could hit the tire and do that. So, off I went again.
As I lay in the street looking up at the sky the second time. I had an epiphany. There was in fact enough give and twist and spring in the forks and wheel and spokes to close that 3/4 inch gap by which the can could NOT otherwise touch the tire and jam the wheel.
Ever since, I do consider the potential for twist and bend in almost anything I do. It causes me to go a couple miles an hour slower under stressful maneuvers than I otherwise might have. I have often seen and noticed the give in a steel beam, or the sway in the towers I used to climb for work. I have read and seen the engineering specs of what I know. And I totally know, that an early Ford front end can and under certain conditions will go negative caster for a moment.
All that said. I am putting together two brass Ts for my use. For a couple reasons, I intend to start driving them without extra braces. I reworked both front ends myself. I took extra care to make sure that everything is tight, and some things may even be stronger than new.
I do highly recommend using the added brace. If I in any way do not like the feel of either of these two cars when I am driving them, it WILL get a brace, and fast.
Drive carefully, and enjoy, W2
Don't forget your bicycle incidents. By the time you figure out the steering feels "funny" it will be too late!
Put on the braces now!! We don't want to lose you!
Thank you David D.
The way things have been going lately in my life, It is nice to know someone cares.
Always, drive carefully, and enjoy, W2
It says in the old article above that Mr. Ford told the driver to "step on it". Step on what? Sounds like he wanted the driver to slow down.
Ralph, thank you for posting that clip. I have seen it before, but had been unable to locate it.
All our cars have "early" wishbones, and I've thought of adding some type of brace (but have not to this point). Probably the worst "offender" of our cars, for the steering wheel being jerked from your hands is the Model N. However, for some reason, Models NRS were not given the short turning radius the Model T was. The wheels simply do not have the turning "travel" a Model T does (I suppose Ford engineers found they could give more turning radius, and did with the T).
I've not checked, but the other reason Ts turn a shorter (and so are liable to have the wheels 'locked" to one side or the other in a sudden turn, curb, hole etc) may be the longer wheelbase, but I think the travel distance of the turning system is greater on a T.
Wayne, we all care about you, so be safe (as with all of you),
The reason I asked this question was because I wonder how many times the wishbone gets blamed when it is not at fault. Seems to be the first conclusion some jump to. If we assume it cannot go negative without permanent damage, and we have a wrecked car to inspect that does not have permanent wishbone damage, then we can assume the wishbone was not at fault. Of course, if we assume it can go negative without permanent damage, then we would never know for sure if it played a part or not.
The other thing to consider is that negative caster does not necessarily result in immediate catastrophe. It only results in the tendency of the front wheels to want to turn to one side or the other rather than tend to track straight ahead. The tendency for this to happen increases the further left or right the wheels are, meaning the problem tends to compound itself. No doubt, this can cause an accident, especially when it happens suddenly.
I don't mean to minimize the seriousness of this phenomenon, but I don't think it is a good idea to assume this is what happened every time a early wishbone car is involved in an accident.
I don't believe that an early wishbone necessarily initiates an accident. I do however believe that when stressed beyond normal, an early wishbone will yield easier, allowing the situation to become worse, or in other words, less recoverable from a control perspective.
Here's a link to five different after market accessory wishbones for above the axle wishbone front end stiffening.
My question is where do the rods bend and do they need to bend before destroying the next part of the car? Was/were the rods made to be a first failed or crumple zone to save the rest of the car/driver?? I have never seen any bent,so where do they bend?Bud.
I have a 15 Touring with the above axle wishbone. It has a under the wishbone brace, but its flimsy looking and I'd like something better.
Is it possible to completely replace the over the axle wishbone with a later model under the axle wishbone and discard the aftermarket brace ?
Would I need to change out the perches ?
Bud -- Yes, you'd need the later perches and wishbone and nuts. You'd probably also need the later-type spindle arms to avoid a conflict between the tie rod and wishbone.
I agree with you that people often place blame in the wrong part. Rollovers often break wheels. Breaking a wheel can, but rarely does cause a rollover. The biggest cause of rollovers in a T is its high center of gravity. If we were to have to stop driving our Ts for that reason, a few million people would have to give up their jeeps.
However. There are other factors we need to be aware of.
The earlier front end is both weaker, and less stable than the later front end. However it will not by itself cause a serious accident. Some other factor must come into play, speed for one. Sharp turn or rough road for others. For several reasons, the "tip-over" point between a minor problem and a major accident is much lower with the early front end. The early front end does contribute to the problem.
The biggest part if the problem is simply the placement of the wishbone above the axle. The road, the wheels, and the axle, all have greater leverage to bend the wishbone than the wishbone has to prevent it. Even a good road driven straight WILL cause the front axle to shake and vibrate many times the amount a later front end ever will.
Add to that placement, the wishbone itself is much weaker. Simple examination shows that the tube it is made of is smaller than the later wishbones, especially at the axle end where the wishbone has the least leverage advantage (later wishbones have more taper in their tube). Careful examination shows that the tube on the later style wishbones is also thicker. Both factors make the later wishbone itself nearly twice as strong. Try bending a few of each and see what you think. I have.
Couple all that with two little straight pins in straight holes to attach the wishbone to the axle, and you have a recipe for the shakes.
I do and often recommend using a brace. Personally, I like to keep cars as close to proper era as reasonable. A simple angle iron brace, properly fitted and tightly bolted is all that should be needed. And they were available during the brass era, therefore are era correct. It may not be quite as strong and stable as the later setup. But it should come close.
I have seen a few Ts after collisions. The later wishbone USUALLY will bend in the middle if the front axle is pushed back with much force. In many cases, there is no apparent damage to the pan. However a trip to the straightening jig would probably be in order.
On one Endurance Run about 25 yeas ago, a fellow speedster driver hit a deer with his right front wheel. He did manage to complete the run. The front wheel was bent back. The axle was bent and twisted. The wishbone sagged about three inches in the middle.
Drive carefully, and enjoy, W2
Thanks for the answer Mike!
As I posted on another thread:
All I can say is that the early radius rod was a bad design. Any load pushing on the front end will cause deflection, but the question is, to what degree? More than likely, a fairly insignificant amount under normal driving.
A large force will put a significant moment on the radius rod at the most obvious point, right where it enters the perches. Put a large enough force on the front end and it will snap the wishbone most likely right at that spot, or at least bend it.
On the later design, there will be some deflection as well, but MUCH less, and it will take much more force to cause permanent deflection or failure than the early style.
It's all just a matter of simple leverage. Plus, there must be a reason why Henry built the vast majority of Ts with the under-the-axle radius rod!
Here's one where it looks like the early wishbone didn't get permanently bent. A rear wheel seized up; oak spokes broke.
That's a picture of a car that was going too fast and rolled over, pitching the unlicensed driver and his friends out. They were all very fortunate to survive.
In no way shape or form was this accident or any other accident the fault of wishbone design.
Please review the earlier posts on the accident that Brent Terry's son had. If I recall an accessory brake band seized causing he flip. Not speed and I do believe his son was licensed at the time. Facts please not just innuendo.
I'm sure others will recall.
I forget to add this in my previous post.
First off, I am in no way saying that the early radius rod causes accidents, but to answer Hal's question, yes, the early radius rod can and will flex towards negative caster even under normal driving conditions. However, the amount it does so is insignificant. It takes a very large force for it to go into negative caster substantially.
The accident occurred in 2009. It's documented in the forum by one of the boys' father Brent Terry. He stated then, that it was a friend of his son's, a licensed 16 year old boy at the wheel. Not his son. He knew how to drive a T. However, Limited experience, and being overwhelmed by the vaguarities of model T driving combined with bad luck caused this accident according to Brent.
There was no failure of accessory brakes.
Speed did not the root cause the accident, though it was a contributing factor, as was a high center of gravity. An inadvised abrupt turn was the root cause (see limited experience, above).
In this particular case, neither type wishbone would likely cause nor prevent such an accident.
As originally posted in 2009, the picture was part of a very clearly stated/defined event and should not become a source of any speculation here, when all of the facts of this specific accident are known and were presented with the pictures.
It is apparent that Ralph is willing to use any picture of a wrecked Model T to further his quest to cause fear and instill panic in anyone with an unmolested Model T.
One cannot imagine how this must cause pain for the people who recently lost their mother, friend, and club president through no fault of the wishbone design.
Ya'll slow down and enjoy the ride.
Read the whole thing again, Scott, as I did before posting this. Brent reported they found the brake cable wrapped around a rear wheel, locking it, due to a shoddy weld.
My point of those two pix above was to show broken oak spokes, and as an aside, the wishbone unbent. I did not speculate on whether the wishbone contributed. The wheel should not have failed, regardless.
Your logic is flawed, Royce. If the car were faultless, as you say, you are then blaming the driver for the accident. I don't believe the driver in either accident was at fault.
I see two instances of a broken front wheel and a rollover accident.
Forum 2013: Wood Spoke Safety
By David Cockey on Sunday, July 28, 2013 - 08:20 pm:
"We did a 3/4 roll in our 1916 touring car four years ago. The right front steer arm and spindle bent and the front axle was twisted. The wheels had been rebuilt several years previously by Noah Stutzman of Baltic, Ohio with hickory spokes. No signs of cracks or other damage to the spokes. The maximum lateral run-out of the wheels was less than 1/8" total. I pressed the hubs of the wheels and the spokes were tight."
From June, 2009:
"My only memory of the incident are of the steering wheel being jerked out of my hands and car feeling like it was rolling over. A quick inspection of the car shows everything in the front suspension and steering in place though a number of parts are bent. The Noah Stutzman wheels are intact with the tires still on the rims and inflated. The car was rolled into our garage. I really don't know what happened, and can't offer any speculation."
My take on where this thread has gone is feces happens, all you can do is try not to step in it.