Pelham bits - long shank v shorter shank

[Orchardbeck]

Can anyone help me, I have begun to ride my mare in a pelham with a Cambridge mouth and it seems to have quite long shanks.

I have seen others that have shorter shanks and I wondered which was most severe, or if there is a difference. Can anyone explain?

 

[Red-1]

The longer shanks provide more leverage, so the curb will tighten more easily, and there will be more pressure.

As with most bits though, it is all about the hands that hold the reins.