What exactly do you mean "are there panniers that fit racing bikes that do not have the fixtures?" By fixture do you mean a rear rack? Panniers obviously hang from the sides of racks. Rear or front. For a Transamerica ride I am guessing you are traveling loaded. Maybe lightly loaded, but you can only go so light if being self contained. Tent, sleeping bag, cooking ware, etc. I suppose you could sleep under the stars in a tarp but I would not advise this. It would be light though. If you are doing the Transamerica credit card touring style, then you can travel real light since you only really need a FEW extra clothes and toiletries. You can use P clips to mount a rear rack to a racing bike and attach panniers and load them very very lightly. Not load them down for a loaded tour though. Or use one of those big Carradice bags on your racing bike saddle and carry quite a bit of stuff for credit card touring. Or a seatpost rack and rack bag and credit card tour. Or the rack bag on the rack attached via P clips and credit card tour. Or maybe even one of those bigger Camelbaks with lots of storage space and credit card tour.
For a racing bike going loaded, the BOB trailer is probably your only solution. Cost is $300 or so I think. Then you can travel loaded across the US.
