Yes, Tim 'Hitman' Horton is indeed his nickname, just like mine is 'DZ' (Danger Zone), although probably not for the reasons you think.
So yes, I do use manual exposure but I cheat a little bit. Firstly, I have a user setting on my camera that allows me to pre-program settings on my camera - as long as the dial is set to "U2" my camera will start on f/4 (used to be f2.8), 1/800 (used to be 1/500), EV - 0 (I used to have this on +3 but recently changed it), Matrix Meter mode for lighting, and auto ISO. I've talked a lot about how I've been experimenting with settings and so I've recently changed them to what I commonly use.
From there, it's mostly about tweaking the shutter speed, sometimes the aperture - but mostly due to available light rather than depth of field, and exposure depending on what the sun is like in the background. I usually have at least 20 seconds before the group has caught up to my spot - plenty of time to dump the bike, grab the camera out of the bag, tweak the settings, and if I'm lucky fire off a test shot...