Carbon fibre engineer's advice sort after,,,

Yes, used a QR and Brake bolt mounted Axiom 3 point rack on a carbon framed racer no problems for light loads. But do take the advice about a higher volume back tyre, a 23 on on an open pro is pushing it, and changing tubes with one of these racks is quite a lot more painful

Also the Audax fraternity use Carradice campers and nelsons with the Expedition rack year in year out without any problems. The weight being carried high on the frame is less bother than the wind resistance caused by frame bags or large panniers. You can also reach the pockets while riding.

And a bar bag, even a tiddly one, will help a lot. Put your camera, wallet, a few hours of food and extra clothing bits in it and you'll save yourself a lot of mucking about. Practice getting your camera out and taking photos without getting off your bike and you'll save HOURS on your jogle.

I used a QR mounted rack (Toba Randy) with a Giant seat collar with rack mount and 2 large axiom typhoon Aero DLX panniers to cycle for two weeks all over Nova Scotia including the Cabot trail on my Giant TCR carbon with no problems. I had the bags loaded to about a total of 25lbs and rode 3-4 day unsupported loops staying at B&B's so I didn't camp but had about 5-6 lbs of tools and parts in case of breakdown. It was amazing how well the bike handled with all that weight on it, and I had lots of room for everything. No damage to the frame whatsoever

John

only thing I would say, after seeing it happen
once, is the extra load "can" push the wheel out
of the dropout ... true this was only once and
easily fixed but the seed of doubt had been
planted !!!!!

I was going to link to the alpkit bike packing range of kit as well.

Yes it probably wont hurt the bike in the short term using p clips but hard point attachments clamped to carbon does not make me feel warm and fuzzy, seat clamp attachment using maybe an M-Parts clamp with eyes might well work and the rack running off a QR mount sounds like an idea also.

For inspiration, google for images of bikes used on either Paris-Brest-Paris, or our own London-Edinburgh-London. Plenty of riders use carbon. Google for "bikepacking" too. Bikepackers are experts at carrying stuff on bikes.

I agree with others here, that you should use a combination of saddle pack, bar bag, or even a frame bag. Apart from a weight advantage, they make the bike far more aero than panniers on a pannier rack and, since you have a carbon bike, I'm assuming that you're probably keen to consider not just weight but aerodynamics too.

If you're on a tight budget, or you just don't want to spend a load of cash for just a one-off event, replace your bottle cages with ones that mount behind the seaddle, cut two triangles of "coroplast" just slightly bigger than the main frame triangle, cut some small slots, secure with toe straps, and you've suddenly got 5-20 litres of enclosed luggage space (depending on tube diameters and the frame size). Incredibly aero, seriously light when compared to the alternatives, and good for printing on if you're raising cash for charity. Good luck with your ride.

carradice also make a seatpost-mounted bag that might work for you:

http://www.carradice.co.uk/index.php?page_id=product&under=range&product...

these are definitely a better option than beam racks, might be a neater solution than a QR rack too if it's big enough to swallow the stuff you intent to carry

other option is a frame bag. Alpkit will custom make one to your frame dimensions.

http://www.alpkit.com/products/stingray

I have two friends who use sestpost/hub qr mounted racks on their PX procarbons and have done with no issue for over 18 months. One of them uses a bolt through hub rather than qr, only m4 bolts, not sure of the hub make though.

carbon always explodes and everyone always dies instantly... lol just joking.

petertaylor123 I would say your logic is sound. I am doing my masters in motorsport engineering at oxford brookes [just sayin' ] and I am planning on taking my full carbon specialized sl3 tarmac on tour this summer.

The 'rack supported by the quick release' jobby works fine. A couple of mates resorted to it when we rode to Rome and they held up fine. Why wouldn't it? lovely shimano XT 5mm diameter skewer just sucked it up, didn't moan once. Just make sure you do it up tight!

What I would say however, is if you start bombing through potholes with an open pro rim and 10kg on a rack, you might get a few surprises. It's high spec Aluminium alloy, but it's a narrow and shallow rim. A mavic A719 would be better as it's wider, or even better, something with a bit of depth to it. The stiffness of a beam is proportional to the cube of its depth, so even a 30mm deep rim will hold up a lot better than an open pro. Yes - a 50mm deep rim would be even better... yep, an 80mm deep rear rim, 25mm wide, with 36 spokes would be immense, and it might even fit in your frame! I've done a spot of loaded touring (and loaded tandem touring) and it's always the rear wheel that starts popping spokes.

Also you kind of want to be running the biggest volume tyre you can fit in your frame, e.g the new gp4000s II 28mm. (£50 a pair from rosebikes) This will reduce your rolling resistance and decrease your chance of pinch punctures. A wider rim, i.e one seats the tyre beads further apart from each other gives the tyre a wider base and further increases the volume.

10kg on the rack is more aggressive to your wheels than an extra 10kg on your arse... basically because hitting a pothole is a dynamic impact, with a big fat bum getting in the way and reducing the peak contact patch force. Also getting out of the saddle over real nasty terrain really gives the wheels a breather. That 10kg on your rack however, is just going to sit there in waiting, ready to ping your spokes over the first big pothole and there ain't shit you can do about it! (maybe bunny hop your whole laden bike?)

This is my first post on a bike forum as they're usually a bit dull and naff, but your question particularly tickled me, so anyway good luck and let me know how it goes.

Gavin aka rainman onwheels

Why not think about something like the Revelate Designs Viscacha

https://www.revelatedesigns.com/index.cfm/store.catalog?CategoryID=4&Pro...

It took Mike Hall around the world, I think it'll do you for JoGLe

Your reasoning seems sound. A rack that fixes to the seatpost and to the dropouts will be better than a beam rack that applys a torsional load through the seatpost alone. Also 10 kg is minimal and your seatpost and frame is designed to cope with a lot more than you will be carrying.

Planet x advice seems a bit numb. Those beam racks are not the best design from an engineering perspective. Having personally seen one swing around on a bike in front of me, I wouldn't trust them. But plenty do use them with no problem.

Although I can't vouch for the other type of rack either as I use a proper rack when I need one.

Oh and I'm an engineer by profession for what that counts.