Horse running through the bit (while schooling)!

[squiggly]

Hi all, new on here and wondered if anyone has any suggestions regarding a horse that runs through the bit. Only been riding the horse for a couple of months and have to say he has improved but every time I ask for a transition he just runs through the bit and goes faster losing rythym. Not particularly on the fore hand. His first answer to everything really is to go faster! Have changed bits (to softer, nicer, different shapes....) to no avail.
Have ridden up to medium level, had horses for a long time and I am flumoxed! Gone right back to basics with him but the transition thing is driving me mad! Any suggestions folks?

 

[kerilli]

umm, train him to voice commands and/or use a neckstrap and train him to react to a tug from that too? work much more on half-halts so that you can do a series of these before a transition so it's nothing he can overreact to? do tons of work in walk, and then very slow trot with lots of walk transitions, halt transitions etc, basically keep everything slow, no adrenalin etc. i'd get teeth, back, saddle checked if you haven't already in case he is reacting to something you don't know about...