As usual, Joe-Joe & I are in agreement. But I do have a slightly different point of view, which is that racing horses are seldom taught the basics or bit response that dressage horses are taught. The problem may be less a bit problem & more how the horse responds to bit pressure. We english riders are taught to move our hands forward to soften the bit tension, but few are taught to simply open their fists/fingers slightly to soften the bit. Coming off the race track, a horse will have to be taught to listen to a soft bit, and then to respond to it. This method also required that the rider be aware of how much tension he/she is carrying in his/her arms, shoulders & even back. Soft hands requires that these sets of muscles also be relaxed, or tensed, depending on how harsh or soft a bit the rider wants to use. It will take some practice to learn to control these muscles in groups, but if you can master this technique, I think you will be pleased with the results.