Its called the pucker factor
...seems you suck the bike backwards due to fear. I also have carried out investigation into this strange and unusual occurrence.
I have been reliably informed that it is the same principal as putting a jet engine into reverse. I, like yourself, was unaware of this freakish behaviour. It is not uncommon for those who ride motorcycles to experience this at moments of extreme stress.
I would not advise any body to try this or to rehearse this feat. As sometimes the engine misinterprates the signal and extreme downward thrust can be caused
...the effects of this on undergarments
can be and are dire as you can imagine. This is another feeling experinced by motorcyclists on odd occassions. I hope this helps to clear up the query.
