..are not so good, at least when it's mounted sideways and flies off the rack.
All that talking about how I hate the TT bike? Karma...I dropped it off the back of the car this morning at ~70 mph. One of the wheel tray bolts came out (this has happened once previously without a bike on it; crappy design) and it flew off. I happened to be looking in the rear view mirror and got a great view of parts bouncing in the air, bike pinwheeling on the pavement, and the truck behind me trying to avoid it all.
Luckily nobody was hit and the bike wasn't run over. The damage is surprisingly light; it landed on the non-drive side and ground a nice parallel edge on the basebar, left pedal, seat, and rear skewer. The basebar's usable, the other parts are toast but it could've been worse. My Powertap rear wheel is leading a charmed life; it has now survived a frame breaking crash on one bike and a 70 mph asphalt spin on the P3 without damage.
The weirdest part was that I had just passed a local rider who happens to be the wife of a shop owner. I honked at her..and about a second later watched the bike fly off. She was undoubtedly thinking, "WTF?!". She helped me get the bike out of the road and told me I should come in and buy a different rack.
I am writing a nasty email to the rack manufacturer. The wheel trays are held on by carriage bolts that go in from the bottom and knobs up top. No retention system for the knob or the bolt..when the knob vibrates loose and comes off, the bolt drops out the bottom and ...weeee're flyyyiiinnnggg. I'm going to change the tray retention system to bolts inserted from the top with nylock nuts. Screw tool-free adjustability.. I should've done so previously.