I’ve heard that additional parts can be bought to make the micklem competition bridle bitless. Is this true?
In the UK I think they come with the pieces to make it bitless; there is a copyright infringement in the US. You might be able to rig something up yourself if you could find pictures of what the straps looked like (I don’t think this would be considered a patent infringement since you aren’t doing it commercially, but then again I know next to nothing about patent law).
That bridle is very close to bitless to begin with. If you tie the cheekpiece to the bridle tightly enough (using the clip from the D ring of the chin strap to the cheekpiece of bit), nearly all the pressure of the reins is transferred to the nosepiece.
Thus, if you could substitute the bit with some similar cheek rings and no bit between them … I wonder … ? Mainly the part going through horse’s mouth (bit) helps stabilize the whole rig, so you might still need to add something if you take away that piece. An extra tie-down near the chin strap maybe?
There are two ways to make it bitless. One has straps that make it like a Dr. Cook bitless bridle. That is the part they can’t sell in the US due to patent infringement.
My multi-bridle came with the strap for the other kind, which is a strap that goes under the chin and through the rings on the noseband. If you look at the Micklem web site you can see close-up pictures.
I had to buy two Micklem bridles in two sizes to make one bridle that fit my mule, so I’ve got two of those straps. If you decide you want one after you’ve looked at the pictures online, PM me. I might be able to make you a deal. 
However, I will tell you that I tried the bitless arrangement and did not care for it. I wouldn’t suggest it unless your horse is very responsive to rein cues and does not pull.
Edited because I failed to mention the third way to make it bitless which is to simply remove the bit and fasten the reins to the dees on the noseband. But, I didn’t like that, either. The noseband twists side to side when you pull on the reins.
You can take parachute cord and attach it so that it will easily mimic the Dr Cooks arrangement. I’ve never liked the Dr Cooks but I’ve used parachute cord to make a gag rein many times. easy and cheap.
My gelding goes best in the scawbrig attachment - the strap that goes under the chin. The only way to obtain them here, that I am aware of, is when purchasing a multibridle, or used from another CoTHer… One could be made from a piece of leather, a rubber keeper (for attaching to the chin strap), and two rings. This set up has enough pressure for my horse, but not too much. He does not go well in the side pull configuration, as the bridle is so padded that it’s easy for him to “forget” that I’m there.
You can use it as a sidepull. Just remove the bit straps and attach your reins to the D rings on the noseband.
