I'm looking for any ideas people have on taking a 40L backpacking pack on a tour with them. I like then idea of going for an overnight hike while I'm touring to let the legs do their natural thing off the bike and on the trails. The only idea I have is putting the pack on top of the rear rack in between the panniers which is less than ideal and might interfere with thighs while pedaling. Any other creative ideas?

Do you need 40L for an overnight? Check out some diff ultralight packs that dont have rigid frames and can easily be packed away.

I'm a big fan of Six Moon Design packs. I carried one for 1200 miles on the AT a couple years ago. ULA is another really good brand to check out.

If you have to have that big of a pack then a trailer is a possible solution. But like nickthebeard, an ultralight bag works for me, I use a g4 style bag that actually is about that big but designed for twenty or so pounds max. It rolls to the size of a soda can when empty. I sewed mine myself, the instructions and pattern are free online and there is a yahoo group dedicated to making them.

Ditto the G4 which you can buy pre-made from Gossamer Gear. I just got one on sale for under $80. I used to use their G5 which only weighed 8 oz or so but they discontinued that one. The advantage of the frameless pack is it's easy to use it as a stuff sack for your sleeping bag, or just roll it up inside a pannier. If you get your load light enough, you can put everything in your pack and not bring panniers. I tried that once and didn't like it much, but some make it work. I will probably try it again some day.

I enjoy multi-day touring to trailheads and then going on multi-day hikes. The pack is also a decent carry-on if there's a plane trip in your itinerary.

Good luck figuring out a system that works for you.

Not creative as it's just Shopping.. and buying stuff.. but it's practical stuff for this purpose..

A Burly Travoy trailer would be excellent , you can attach a Back Country hiker's pack onto it .

::Bike Trailer - Travoy Commute Bike Trailer - Burley--BURLEY--

I bring a Gossamer Gear Mariposa pack. I removed the frame and sitpad so it folds down small and goes in a pannier. Before, I put a pack on top of the rack and rear panniers and it works just fine. Make sure no straps get in the wheel.

the pack will not be carrying any extra load above and beyond normal pannier loads, it is just another way of carrying your stuff.
Partially loaded 40l backpack should sit OK on the rack, just keep the straps under control.

+1 it should be manageable. I've even strapped a loaded pack on top of the rack. If you pack light it should work fine. If you pack heavier, you can put the stuff in panniers and strap the empty pack on top.

I am thinking of carrying most my gear in an 18 liter pack strapped on a light rack for my upcoming dirt roads tour. For me that is plenty for an overnight hike, but if it wasn't I'd consider my 30 liter pack or if a bear canister was required my 45 liter pack.

Wear it and leave the panniers at home. I have used a Mountainsmith backpack each of the past two years as my panniers. I load everything into the backpack and put it on my back, just like I would if I was going hiking, and then I hop on the bike and ride 100+ miles a day. I don't have racks/panniers on my bike. I rarely ride without a daypack or a backpack on my back, even around home. I use the packs for running errands all the time.

I've got an Equinox ultralight pack that I turn inside-out, fill with stuff, and strap to my rear rack. I use my foam sit-pad as a buffer between the rack and pack. I've only done short weekend excursions this way, but it does work.

i had a backpack (50l kelty redwing - not a weight weenie pack), normal touring stuff, and a bear keg (the big, heavy, black plastic ones) on my xtracycle (with freeloader bags) a couple summers ago. the backpack and bear keg functioned as slightly heavy, bulky containers when not doing backpacky and bear keggy functions. i rode from lancaster metrolink to yosemite along the s-c route, doing overnight/multiday hikes at mineral king and yosemite valley. the abundance of food storage containers in yosemite parking lots let me lock my bike, stash most of my stuff in a bear container, pack my pack, and walk from the valley to lake merced, tuolumne meadows, clouds' rest, and back to the valley without too much stress. xtracycles can carry way too much crap, but sometimes that capacity is handy. lemme see if i can find a couple pics

edit: you probably don't have an xtracycle, so this probably isn't too helpful, but i'm putting it out there anyways

edit: found some pix, but they are too large. is there no faster way to do this? does bike forums not have some sort of auto-size tool or anything?

jesus christ it's not even a big picture. i give up

What are you carrying that requires a 40l pack for an overnight? 25 would be more than enough, you can even overnight with just a butt pack as long as you aren't taking some absurdly large tent.

Can't you just right click it and use the resize feature?

I use flickr to manage my online pictures, and nothing much else.