The Metro stations around here used to have racks that had two pieces that scissored up after you put your bike in a track. The two sides had rods that went through your frame and both wheels,then you would put your U lock through the whole thing. It allowed you to lock both wheels and the frame with just one lock. No idea how effective they actually were;I saw many of them broken,so I don't know if bikes were taken or if they just weren't maintained properly.

Of course,there's always bike lockers,which most of the stations have now. Better idea since you can leave things like helmets and accessories on the bike,and none of it can be seen without breaking into the locker.