Bit Work And Speed

Ring bit with spoons. Our worker is at the 6f heading for the 5f for a one mile 2m gallop. On board our jock is supposed to be doing everything right to perfectly accomplish this exercise so that when we're done we can go on to the next work as planned.
Assuming the well trained push button horse, what's going on in the rider's mind as he passes the 6f?

Two things actually. #1 transitioning from warm up speed to work speed, and #2 lead change ahead likely right before the 5.5f pole on the one mile track. As the gallop has been slow, this lead change is other than automatic with the horse who is yet without fatigue on the left lead.

So, two things have to be done correctly with one eye to the right hoping the starting gate is clear as we're hopping by. To the horse, of course, it is unknown whether today's gallop is just a routine slow gallop or otherwise. As always the horse will want to go and by this point on the race track probably starts to feel absence of the normal rein/bit restraint at the slow gallop. For the horse here, something's up.

With many of them, thus, they will speed up on their own at the 6f, or it takes very mild urging with one of the riding aids (foot pressure, voice, whip tap on shoulder, taking up the reins which really means just a slight shift--the horse will feel in its mouth even a slight movement on the reins etc. Noted last post that these signals trigger the flight mechanism in the horse or for the experienced campaigner that enjoys their work its merely the normal go signal.) For the rider here the problem is more one to restraint once you get to the correct speed than it is increasing the speed.

One other factor comes into play. We've just crossed the 6f, the speed up has begun, but there's a lead change ahead. First note that horses naturally speed up out of a lead change. Unknown exactly why, but suspect 1. lead changing itself takes effort and adrenalin, and 2. the horse goes from the fatigued leg to the fresh leg and is more easily thus to do what it wants, which is "go".

At any rate, the rider knows there's going to be a spurt at the 5.5 pole due to the lead change Again, for reasons unknown, the lead change at the 5.5 pole with every horse I've ridden is always, and each and every ride, the most enthusiastic lead change around the race track. The horse almost always will enthusiastically come out of the lead change at the 5.5f.

For this reason, the rider likely will decide to be at the :15 rate of speed coming out of the lead change at the 5.5f. That's the thought process--#1 get the lead, and #2 get the correct speed.

This has now occurred with the 5f just in front of the rider. The horse needs to be held at the :15 rate of speed and restrained from going faster. Role of rider and bit in this process, next post.
Training:
Three days of rain. Off.