If you're above V1, you're going, period. That you have more runway in front of you means you have an obstacle free clearway...that's good...but it's not there for stopping.
High speed aborts are dangerous. Period. Ever wonder why the FAA limits abort demos on practical tests to 40% of your refusal speed? The FAA knows, based on history and statistics, that a high speed abort stands a fairly high probability of ending badly, and there's no reason for it.
If I have a long runway, I may leave well enough alone and use the calcualted V speeds. If it's a shorter runway, I may include a primary refusal speed; any malfunction prior to that speed, I'll abort. Above that, I'm only aborting for critical items, such as engine fire, engine failure, or loss of directional control. My decision, made before ever entering the runway environment, may also be tempered by surrounding terrain, runway gradient, runway surface condition (eg, contaminated runway), and so forth. NBAA and other safety organizations have suggested 80 knots as an all encompassing refusal speed (or decision speed, if you will), where one will abort for any light or indicated malfunction.
You should have briefed the contingencies. If you're past V1 and encounter a problem, you're way, way beyond the time to be reconsidering or second guessing your preflight planning and briefing.
By the time you hear V1, you're right on top of or passing through Vr and well on your way to V2 in many cases. In most aircraft, that transition period doesn't last long, and trying to split knots or one second from the next is thinking too much...it can get you hurt.
A more interesting possibility that I've seen in practice on actual take offs and in simulator sessions, is a split between crewmembers. In the sim, for example, I see a malfunction. The PF is so keyed into the takeoff that when I call "Abort! Abort! Abort!," the pilot continues the takeoff. I've seen this happen under actual conditions. The more interesting question then becomes what to do when faced with a reason to abort, and the other pilot disregards the instruction.
A worldwide generic industry rule, given in various forms, is that one challenges once, and then challenges again. If no response at the second challenge, one assumes incapacitation and takes control. However, that's awfully darn generic, and may be downright unsafe. I've had to do it twice in my career, and on both occasions there was no time to second guess and there was no other choice. But what about on a takeoff roll?
I was once departing LAX in a Learjet with a newly minted captain. He was very, very weak, and I'd been sent with him on the theory that a "strong" (don't laugh; it wasn't my decision) pilot would make up for his deficiencies. This individual was scared to death of flying into LAX; just mention of the place made him nervous. He missed the call to position and hold on 25L, and seemed nearly overloaded. I could tell he was very focused on his takeoff. Just prior to airspeed coming alive I got a master warning and a main cabin entrance door light (forgive me if I get the annunciation wrong; it's been a little while).
I called out the malfunction, and called for an abort. It was within our prebriefed abort criteria, and within the speed envelope. He failed to abort. I called it again, but noted the airspeed rapidly increasing through indicated and then 80 knots. I glanced over my shoulder, noted both the upper and lower door handles forward (door had to be locked, it was probably a handle not fully down or a microswitch issue). Satisfied that continuing was far safer than trying to wrestle the airplane away from him and execute a high speed abort, we continued. I called V1, rotate, and called positive rate.
No response. Again I called positive rate. No response. I said "I have your gear," and raised his gear. The remainder of the initial after takeoff was the same way. After the after takeoff checks were complete, I poitned at the master warning and then the door light, and repeated, "You ARE aware we have a door ligth and a master warning light?"
For the first time he saw it, and I could see him nearly panic. He completely lost his focus, demanding to know "what shall we do? What should I do? We're going to abort! Declare an emergency, let's do a 180 and land!" Absolutely useless.
I told him we were airborne, continue the climb, and once we were passed over to the high altitude controller I'd go back and have a look. I did, and upon pressing the lower handle down, the light went out.
Sometimes an abort, even though technically warranted, isn't the wisest choice, nor is insisting on it.
