tree flex

[raftert]

In the topic about fiberglass or rawhide trees the subject of flex was brought up. When is there to much flex or is this tree to ridged ? It would seem if you had a 1000 lb cow on the end of a rope and are pulling it in a trailer, the pressure on the horn would be constricting the swells on real flexable tree thus putting a pinch effect on the horses withers. I know there must flex but when is it to much?

Tim

[jonwatsabaugh]

Tim,

I've not done any studies on the amount of deflection under load in a western saddle tree, but if I were to speculate, it would be negligable(probably measured in thousands of an inch if that). Contrary to a lot of myth circulated throughout generations it was believed a tree must deflect under high load to act as a shock absorber. A good padding system and a good natural wool skin lining serve this function. In a well engineered and constructed tree, it is my opinion they should not flex at all.

Jon

[Severe]

I think I'm the guilty party talking about flex in a tree.

Here's my thoughts on the topic.

If you set a well shaped tree on a horses back, and it bears fully on his back thru the bars you have a good fit. That is only if he is standing squarely. Watch what happens to your perfect fit if he cocks a foot.

Now think about a horse thats say, cutting a cow, or maybe turning the corner after laying a trip. How far from normal shape is ol roany's back now. At best he's just got a 150 lb rider on top of that saddle or maybe that rope with a steer hitting the end of a rope.

We can fix some of that with the sheepskin and a pad but the more we pad the more we jack the bars off the horses back and the more leverage comes into play.

I think the bars in a well made tree act very much like the limbs in a bow. Depending on the amount of energy put on them they move, maybe only slightly but they move. The grain of the wood prelodes energy to come back to the point they started. The rawhide cover or fiberglass which ever is used keeps the wood from taking to great a lode and breaking.

When bowyers build bows they try to follow the grain of the wood, if they violate the wood grain the bow limb will fail. Unless they back it with something to stop it. They use several things, rawhide, sinew, bamboo, and glass to name but a few. This is like laminating a tree.

If they can store the energy, and release it time and time again without failer they don't have to laminate.

Look at a picture of a cutting horse making a turn. They first have to collect, to get the stop, then while the back legs and hindquarters are turning one way, the front legs, head and shoulders are coming thru a turn in the other direction. The bars in a tree are postioned to flex with the horses back, unless we made them to thick to flex.

I don't think this was done on purpose, I think by trying to fit a horses back it just happen when tree makers started refining trees to fit first the horse and then the rider.

Whats the perfect balance? Depends on the use of the saddle. You can't have, say a roper flex to much. It may pinch a bit when the horse tuns off. Allthogh I doubt theres much of a problem with bars flexing on ropers, more of a problem with horns high enough to have lots of leverage.

Fiberglass may be able to solve some of the problems tree makers encounter. So may things like carbon or kevlar, only time will tell.

One thing I do know, it will take horsemen & horsewomen. Horses can't talk and folks who don't use the gear won't know what a horse is trying to say.

Sorry for so long a post, just my two cents worth. RS

[Rod and Denise Nikkel]

Our opinion is that while there might be some flex in trees it is only under extreme load and would be minimal unless it disrupted the integrity of the tree in some way. There is only so far you can bend a piece of wood without it breaking, and the same amount of flex will cause the wood to break whether it is encased in something or not. The rawhide, fiberglass or whatever is vital to withstand the flexing forces, keeping the wood from bending to the point of damage. Different woods vary in how much they bend (along with other tests of strength) before breaking, so wood choice is important.

While the whole idea of flex in a tree sounds good, we don’t feel it is that realistic. The theory on very flexible trees is that they change with the movement of the horse so they always spread out the rider’s weight evenly rather than varying the pressure under the tree in different places as the horse moves. The problem we see with bars that are flexible enough for a person to physically take and bend is that they will therefore also bend under the weight of the rider, causing increased pressure under the rider and not distributing it over the whole bar surface area. A totally rigid tree that doesn’t dig in anywhere and that is rigged properly will distribute the rider’s weight and the other forces on it over a large area, even if that pressure varies in amount under different areas of the tree as the horse moves. We think this is probably what is happening in reality with most trees today. The bars are lifted by the muscles contracting underneath the whole length of the bar as they turn, etc., but they don’t really flex to any great extent. Up till now no one has been able to really tell what is going on under a ridden saddle. It will take the new technology of things like pressure pads that can read and transmit data throughout any and all activities of the horse to tell us the real story. If that is possible yet, it has only been in the last few years. If not, it will probably be available within the next few years. Then, finally, we will have some facts to base our opinions on.

[JRedding]

Hoping not to get off the original topic but could the treemakers give comments if they feel there is a difference in the amount of flex between an all hardwood tree and a pine. And what you feel are the benefits of each material.

[grumpyguy]

I am just getting into tree making, but have had a lifetime of experience with wood working. In alot of cutting and barrel saddles I have seen pine encased in fiberglass. Most appears to be a "yellow pine." (usually from the south east united states.) That particular pine is some what tougher and has a better strength and flex than most western spiecies. The common pines here in the west are soft and brittle, great for mouldings window casings and the like but not used for items requiring structural strength. We use fir out here which is far superior to any pines locally. Some old time saddle makers used douglas fir extensively for saddle trees as it was common in the west. Those were of course traditionally covered with rawhide as you are well aware. (It is still the construction material of choice by most constrction contractors in the west.) Douglas fir has a very flexable nature when green and retains a surprising amount of flex when it is dried. It will however split fairly easily.

I have also worked with birch, ash, hickory, walnut, and found most are less flexable than douglas fir but are stronger, harder and do not split as eaily.

Still as far as saddle trees and flex, I beleive it is negligable. You must consider that the rigging is made of flexible leather and when push come to shove the leather will flex/stretch and give way before the tree will. That is the reason for proper rigging adjustment, breast collars and properly fitting and padding the saddle in the first place. No question a horse that works at doctoring cattle all day will be sore as any of us would, but alot depends on the rider. Those who work slowly, methodically and carefully will in the long run doctor more cattle without soring thier horse. Those who run 'em down and rope them hard and fast will wear out more horses, and stess the cattle, with out getting as many doctored. Kind of compares to a man carrying a back pack. Most of those frames are not very flexible either. (especially the external frame packs.) The frame either fits the person or it doesn't, add to that someone trying to race over rough ground and the heavy weight, there will be an amount of pain involved. More than likely the fellow who adopts a reasonable pace will trave farther than the man who is trying to run a foot race with a backpack and he'll do it with less pain and suffering involved.

We all are interested in maximizing comfort and performance, thus the variety of new ideas in saddlery. As long as we continue to search for new and better materials someone is bound to come up with something. This is also an industry where most like myself cling to the old tried and true methods and materials.

Now comes my disclaimer, this is as others have said only myhumble opion so you may take for what it is worth to you or discard it altogether.

[Rod and Denise Nikkel]

Hoping not to get off the original topic but could the treemakers give comments if they feel there is a difference in the amount of flex between an all hardwood tree and a pine. And what you feel are the benefits of each material.

Jim, how much do you really want to know? Your question got me going back to the books. But I will spare you the details…

Basically, the only thing on a tree that practically may flex is the bars and as we said before, we don’t think they do or even should flex. And the quality of the covering on the wood is what takes the strain before it even gets to the wood. Once at the wood stage, there are differences in how wood breaks most easily, (across the grain, with the grain, etc.), how much pressure it takes to break it and how much it will bend before breaking. Just looking at the tests they run for bending a longer beam, the two types of yellow pine rank well up with Douglas Fir as far as bending strength goes, but all are very inflexible. (The flexibility rating on the Douglas Fir surprised me but I checked in a couple of souces and they both agreed.) Yellow Poplar is middle of the road in both of these tests, and the other pines (jack, eastern and western white, lodgepole, etc.) are weaker and more flexible. But does it make a practical different in a well covered tree? I doubt it.

As far as benefits, all we can talk about is what we have had worked with.

The Eastern White pine, which is the only type we can easily get, is cheap. That, its availability and its light weight are its greatest virtues. It also can take a lot of nails without splitting. It can easily be worked with hand tools. But, it is the only wood that has a lot of pitch that gums up the equipment and is a major pain. It has a lot of knots – large knots – that cause a lot of waste when you cut pieces around them (and a lot of weak spots if you don’t). We would not consider using pine for bars because with the stuff available to us we can’t get a bar length of wood without a knot it in. It also doesn’t hold screws very well in comparison to the other woods.

Yellow poplar is close to knot free, and then they are generally small, solid pin knots. The few large knots can easily be worked around. This is its biggest advantage. It is readily available and not too expensive. It has good screw holding ability. It is heavier than pine and is too hard to be easily worked with hand tools.

Maple or birch work well as a section in the center of the fork for added strength. They are much stronger than pine. They hold screws much better. They don’t have lots of knots to work around. They are more expensive and they are heavier than pine.

Aspen is a light wood that we prefer to use in place of pine in our cantles and the non-hardwood portions of the forks. It in comparison to pine it is cleaner to work with, has a lot fewer knots, is about the same price, and can still be worked with hand tools but holds screws better. This year, however, we can’t seem to get it. With the downturn in the US housing market the OSB (Oriented Strand Board) market has collapsed and that is where a lot of aspen goes, so no one is cutting the trees. We may need to go back to pine for our cantles and non-hardwood part of the fork. Yuck. I hate cleaning up the mess it makes on the planer rollers. But at least we will have more (expensive) firewood over the winter with all the off cuts!

[Severe]

I'm gonna try to provide a little information here to maybe clarify what I ment without offending anyone. First , I don't sell tree's, have not sold a outside tree to anyone in about 15 years. This is not a attempt to down grade anyones tree's just what I've found works best for myself and the saddlemakers & treemakers who taught me. I know the materials that I use and the rest is only what I hear, and that is not something I would pass on untill I've tryed it.

This saddle was made around 1955, it's here for a relining job. It's a very good example of what I mean on a refined tree. It was made by my dad when I was 2 or 3 years old. As you can see the bars are shaped very thin. The rawhide was steerhide, not bullhide. We switched to bullhide later for the ropers and trippers, also the bronc trees.

Now, what I mean by flex is just this. I can set this tree on my rock, slide a peice of 15 oz leather under the front of one bar. I can then push down on the front and rear of the opposing bar that is off the rock and get all four points of the bar touching by applying around 40 lbs pressure. If I want more flex I'd just add another peice of leather and apply more pressure. This is what I mean by a tree flexing. On a roper I'd want the tree to resist the flex a little more than this tree, but I still try to refine them like I was taught. The more the pressure, the more the wood and rawhide will resist, it trys to return to it's original shape. At some point the tree would fail, we need to leave enough safety margin for that.

This tree and a bunch just like them have have passed the test of time with flying colors. There are other benifits to doing them like this, to the saddlemaker, the horse & the rider.

I've built trees this way for some time with great success, I'm only now starting to understand why.

[Rod and Denise Nikkel]

Thanks for the post and picture, Robin. What type of wood is in that tree and do you still use the same material now?

[Severe]

Rod, The wood in that tree is Douglas Fir in the fork & bars. The cantle is Ponderosa Pine.

I do still use the same wood. If it's a ladys tree or one that will never see a rope I use rawhide that thin also. That is a Quarter Horse tree and has a pelican horn, clearly not made to rope critters. But it does have a couple pretty deep rope burns in the horn leather.

I think rawhide that comes from a older cow critter is also tougher and you can get away with thinner hide, or if you know the fella getting the saddle is gonna really use it hard use older thick hide and frustrate him. He won't get it to break no matter how hard he trys :^)

Look forward to meeting you sometime Rod, love to disscuss tree making with you and what you've found works best and what don't for you.

Robin

[D.A. Kabatoff]

Hi Randy,

thanks for the photo and the explanation. I think there is alot of different perceptions on the point of a tree flexing. Seems alot of people think it somehow helps with comfort etc... It was explained to me along time ago similar to what you were describing; The flex is there to help protect the integrity of the tree. If it didn't flex and was brittle, the first big hit it took would cause it to break. I have often wondered what the point of these trees with rubber bars is?

Darc