For what it's worth, I've just picked up a pair of Sennheiser MX680.
They claim to be designed with "activity" in mind and therefore not to fall out. I didn't want an ear loop as that I find interferes with sunglasses / helmet strap / cap but these have a novel solution to keep them in the ear called an "ear fin". It's a soft, flexible rubber fin that tucks in behind the "rim" of the outer ear.
Good sound quality and well made as you might expect from Sennheiser.
In-line clip / volume control useful for keeping plenty cable slack to allow maximum head turning and if someone at the lights wants to have a chat.
Good colour range (yellow and black only).
Very comfortable, wore them for about 5 hours on Sunday as I pottered about East Lothian in the sunshine. (There was a Tiger Moth doing some aerobatics at Archerfield. I put on Ron Goodwin's Battle of Britain soundtrack)
Good fit as there are a selection of rubber find and little yellow jackets for the earpiece to suit a a range of ear sizes and shapes.
Claim to be "sweat proof". Not sure what depth of sweat they have been tested to.