I queried ToPeak (Todson) about this once.

They thought it was a very bad idea.

Consider switching to SPD pedals if you have road pedals. Unless you're doing a lot of walking, you can get around well enough in your bike shoes.

MTB recessed cleat SPD shoes are a great compromise between biking and walking and the way to go for touring. Here is how to attach a couple of compression bags. Without the tent, sleeping bag an other camping equipment the setup would significantly lighter and more compact.

http://wheelsofchance.org/2010/02/02/ultralight-setup/

I'm using the Tubus Fly rack and Ortlieb Back-Roller Classic panniers on my Specialized Tarmac for the PCH later this month. Contact Wayne at thetouringstore.com. He is extremely knowledgeable. For most competitive calipers you'll have to remove the brake and attach the rack on the recessed allen nut.

Or, check out Epic Designs and Carousal Design Works. They have some sweet seat bags that I would have loved to use but I put my trip together kind of last minute.

Another alternative is to get a service to transport your luggage for you.

Touring companies like Iron Donkey may be willing to arrange for a taxi to take your gear from one hotel to the next. That way you can take as much clothing etc as you need and ride as fast as you want, and just carry repair gear.

If you can manage the logistics, cache what you need at your overnight stops. I Just did a 200mi, three day trip of the rockies in Canada. we dropped small over night boxes at our hostels on the way to our start point. My overnight box included a tshirt, shorts flip flops, travel size abolutions, and chamois cream in a travel bottle. Effectively, I carried no more for three days than I do for one. If you talk nice to the B&B's you may be able to Post you boxes ahead of your trip.

One more place to stash gear on a carbon road bike is to put a third water bottle holder under the down tube. You can buy straps from Zefal that give you the extra mounting points, and then use a bottle that is designed to hold tools rather than water (or use an old water bottle if you want). This is where I keep all of my tools so that I can use a seatpost-mounted rear rack. If your seatpost is carbon, buy a cheap alloy post to use with the rack. instead. If you can't change the seatpost (which is too often the case with modern road bikes) then this bike is pretty useless for this purpose.

You could combine the water bottle idea with a seat bag, if you needed a little extra space.