l am not using a noseband (western bridle).Wondering if l should use a chin/curb strap to keep the bit from pulling through the mouth? This will be for training a green horse. l would prefer not to use a full cheek.

Yes. It keeps the bit from being pulled through the mouth. l have seen many people ''working'' their horse without a chin strap and they pull the rings right into the mouth.

Yes, l do. l keeps the bit from going through their mouth.

It is important to have chin straps on all of your bits. I

You're correct in knowing that a snaffle bit is effects do not depend upon a chin strap. A leverage bit is different - to work effectively the chin strap MUST be used.
So u do not totally require a chin strap with ur loose ring snaffle. On the other hand, a chin strap is cheap (costs less than $10), has no disadvantages or problems that l can think of, & can prevent a bit from being pulled all the way through the horse is mouth & therefore loose u control & cause ur horse discomfort. This is particularily of value in a young horse that may need a strong direct pull on occasion.
So l would advise one. l ride everything with a chin strap, no matter what type of snaffle l am using, & have never had a bit pull through. It is worth the few dollars.

l thought that curb chains are ment to be used on pelhams not snaffles. You can buy a strap for snaffles when lounging. They have a ring on for your line. Cannot remember what they are called

Okay l am reading the question & not understand if ur talking about the rubber stoppers that go on either side of the bit to stop it from pulling thru the horse is mouth, or r u talking about a curb strap?

Using correct terms or giving photos/better examples would clear this up.

Curb straps have no use on a snaffle bit. You would have to understand that snaffle bits r a direct bit, they directly put pressure on the mouth most times In the nut cracker action when it is jointed. Where as a curb bit puts pressure on the pull & a curb chain is used with those bits to add pressure against the horse. Using a curb chain with a snaffle bit will more then likely get u laughed at & people thinking u really do not know what ur doing/how the bit ur using works.

About the rubber pads that go on either side of the bit, I've never used them because I've never had a reason to use them. When l do ride with a snaffle bit it is a full cheek snaffle with keepers. l do not see why u would have anything against a full check. For me they're a better bit. Atm l am using one that is not a full bit ( l am working with someone else is horse & they like u perfer not to use one, they gave me the bit & equipment they'd perfer be used on the horse) l do not use anything to keep the bit from going thru his mouth, I've been working with him for 4 months now getting him ready for showing.

l say: If u do not need it do not buy it. Go ride for a week or so & if it is not a problem, do not get 'em. If u notice a problem, go & try them.

no no no do not use a curb with a snaffle bit!

You need bit guards which are round rubber loops which attach to the sides of the bit (usually a loose ring snaffle). They keep the bit from pulling thru the mouth.

Here is a link for what you need.they are super cheap:
http://smartpakequine.com/productclass.aspx?productClassid=4147

If you use a curb chain/strap you are defeating your purpose. You need to pull the youngster is head around and with a curb strap/chain, you can not. If you are afraid of pulling the ring through the horse is mouth, then either go with a cavesson (noseband) or a full cheek, outside of those, there are not any options.

For the sake of clarity, when u use a chin strap on a snaffle bit to keep the rings from pulling through the mouth, it is referred to as bit hobbles. It is not functioning as a chin strap... it is disabling the bit rings from moving excessively, as when u hobble a horse is legs.

Add...to explain, when u use a lateral rein cue, the hobble will cause the base of the ring on the opposite side of the muzzle to be brought toward the direction of the cue, which will stop the bit mouthpiece from moving sideways in the horse is mouth. It is effective.