I'm going to borrow this from another forum...original thread can be found here: http://www.dailyequine.com/forums/to...?TOPIC_ID=3671
Suffice to say snaffles do not have shanks. Shanks are only found on leverage bits and are an integral part of how they work. I would definitely be interested in seeing your research on the matter, can you name some of the bits you've seen with shanks? (note: the author here is talking about tom thumb bits specifically)
"Marketing. They are Marketed as a mild bit that is good for the green horse or green rider. One reason they are marketed this way is because of the misbelief that they are a snaffle with shanks, making it a mild bit that works as a snaffle and a curb. But that is all incorrect. No snaffle can have shanks. A snaffle is a non leverage, direct pressure bit that can have any type of mouth piece, joint, chain, leather, solid even ported. Many believe that a Curb bit is a bit with a solid mouth piece and many call the port the curb but what a curb bit is, is a leverage bit that uses a curb strap that causes curb pressure on the curb area of the lower jaw...the reason for the name Curb bit. A curb bit can have any type of mouth piece, jointed, chain, leather, solid, etc.
So a Tom THumb is a curb bit. One of the biggest problems with it is that many think it is a snaffle because of the marketing and use it as a snaffle but that can cause many problems to the poor horse. That holds true for ANY jointed Curb bit, but...
Not all jointed Curb bits are Tom Thumbs. There are only three Tom Thumb bits. The english Tom Thumb which is a short(very short) shanked curb bit that has a Solid ported mouth piece. The Aussie Tom Thumb which IS a ture snaffle that looks much like the Full cheek but has the ends flattened like a thumb print instead of rounded. And then the Western Tom Thumb which is the bit most people are talking about when you see Tom Thumb. Of the three the first two are good bits, the third is best left on the wall for many reasons.
Like I said above there is only three TTs(Tom Thumbs). There are many western bits that hold the name but are not TTs. Again this goes back to Marketing. They list anything with a jointed mouth piece and a western shank as a TT to make people think of it as mild and because humans like to group things. There is only one true western TT and that is the bit I'm talking about. Oddly enough when they group these other bits as a TT, normally pushing someone to buy a longer shanked one for control after the horse blows through the TT they are giving them a milder bit in most cases. The TT is bad by design. It has short STRAIGHT shanks. If there is a longer shank or a good curve in it or anything but a single jointed mouth piece it isn't a TT and by design is probably the better bit(but might not be right for the case).
There are many factors that make the TT a poor bit:
Mouth piece- in general the single jointed is thought to be mild, many times because of the misbelief that a single jointed bit is a snaffle and a snaffle is always mild(neither are true). The single jointed mouth piece isn't all that evil but is a pain for many horses. It forms a V shape in the mouth and the point can hit the roof of the mouth and many horses cannot handle that even on a snaffle. Less can handle it on a shank because on a shank the mouth piece will form that shape and then rotate down onto the tongue(which is much more sensitive then the bars). Also on a shanked bit you have the curb strap pushing the lower jaw up into that V shape causes a strong nutcracker action.
The shank- Yes short is generally milder but not always. It isn't just the length of shank that decides the amount of leverage but the ratio of the Purchase(part of cheek from headstall ring to mouth piece) to the shank(part of cheek from mouth piece to rein ring) that is what decides your leverage amount. The straighter the shank the louder and quicker the bit is to react but many times the less release and presignal you get. The wieght, curve and shape of the shank plays a huge role in how that bit acts.
Balance- Balance is very important but is over looked by most people. How a bit balances is going to make it work in different ways. Over balanced bits will give you a good release and presingle, under balanced are best left to good hands on exp. Trainers, and straight hangers are inbetween. That's the basics it's a little more then that.
Release- this is very important for most riders and horses. The release is the reward for doing right. The TT has a very poor if any release of pressure.
Presignal- is your build in half halt, the split second "Hay we are going to do something" that the horse gets to be able to be ready to react. The TT has none so when you cue the horse feels the force of the bit with no warning. The more warning you can give and the lighter you use it the lighter and softer the horse can become.
The use- like I said many try to use it as a snaffle and that just causes problems. Using a shanked bit in place of a snaffle can be a real pain to the horse and hinder training.
Yep I don't like the Western TT, they are better for door stops then in a mouth. There are many, many good bits on the market and for every TT horse I have worked with or helped owners with there has been a better bit out there. Every time I have an owner that tells me their horse is happy in a TT or can only work in a TT I have been able to show them a horse that is much happier with something else, or a bit that was not a TT.
Yes they are widely used and at one time I did use them...until I started to educate myself about bits and found it not only lacking but a real pain to the horse. Think about who most people learn about bits. Many times the people that new riders learn from did not learn it from someone that was all that educated about bits either. Even many trainers and instructors do not take the time to learn more then the very least they need to know. Many stores do not hire based on knowledge of bits...not that I think they need to hire only educated bit people but I have worked with many stores to educate their sales people when they have had problems with that. And many will just use the bit the horse came with and not question it at all. Bits are not simple. There is a lot to them and a lot of people don't care enough about them to learn....me I tend to go over board about them and have a huge collection and I turn into a 5 yr old at Christmas with a new bit or bitless bridle that I have never tried before. I firmly believe that one cannot teach what one does not know so I make a point of learning all I can and staying on top of it so that in the mild of a clinic or class on them I can answer questions."