I think I saw a picture of someone with a fairly large plastic storage tub attacked to the top of their rear rack once. I'm considering doing this or something similar. My thought is to have a container large enough to fit my tent and bedding into, that's why it would need to be pretty large. The poles need about 25" of space to fit, so that's dictating length, and then the rest of the tent plus my bedding dictates the needed width and depth. I already have them in water resistant bags each, but I'd like them to be inside something else as well. Has anyone here done this, do you have any pics of this kind of setup or similar, and or do you have any other ideas and suggestions?

You can Modify Kitty Litter Boxes

Here they are made into panniers, Commercially The Bike Bucket - Bike Buckets

You can DIYa top of the rack mount with a bit of DIY Initiative .. a few Bolts and some velcro perhaps?

KITTY litter pannier!

You might consider just getting an Ortlieb Rack Pack, or something similar. They are durable, waterproof, and are a good size for carry-on situations. They are easy to put on and take off the bike (can be very important), and make a nice compact package. They are not in the way when mounting and dismounting the bike. They have a shoulder strap which is handy when your room is on the 3rd floor of a hotel without an elevator.

+1 - Dry bags are great and the weight is negligible.

I used to use a plastic milk crate (real one) tied onto the rear rack. Not waterproof but easy to use a plastic bag if necessary. A bit heavy, OTOH off the bike it makes a nice seat--I also use it when spectating at big pro bike races. If crowds are thick I can stand on it & have a good view.

My nashbar trunk, about 12.5 L, 615 gr. $40, came with a waterproof cover.

My panniers when on the rack are higher than the rack. Thus, anything I put on top sits on the panniers, not on the rack. I (like Doug64 above) sometimes use the Ortlieb 31 liter waterproof duffel like he showed above and is shown in my photo. Sometimes I instead use a Carradice saddle bag, but that is not as waterpoof.

In Missouri, large plastic storage tubs are called coolers. Here is my large plastic storage tub with custom straps a long long time ago on the Katy Trail.

Weight=heavy. Cold beer in the middle of summer=priceless.

I 2nd the waterproof drybag over the top of the racks/panniers.

If you leave the word "large" out of the equation, a trash compactor bag inside the panniers works for me. I only need the volume of one pannier to stay absolutely dry, so I only use one bag. The trash compactor bag works well because it's white (easier to see into), and it can be patched with duct tape. I also use it as a partial drop cloth when I'm cowboy camping. It's versatile, light, and cheap.

Define "large".

I have made boxes out of coroplast sheet to use on bikes, motorcycles, four wheelers and the like. They can be made waterproof with enough tape and some thought about the design. Great part is; with the election over there is a huge ready supply of coroplast available.

Aaron

OK, by "Large" I mean something like 25"L x 20"W x 12D or a bit smaller.

Geez!! You could move furniture in a bag that big. Your talking like 70 L and I suppose 4 panniers also. I carried too much in bags 1/3 the size. What are you planning on bringing with you? Have you considered pulling 2 Bob trailers instead?

Corplast would work, but you may need to stiffen the bottom. Other option would be a dry bag on a platform rack.

Aaron

We've used one of these for 30 years paddling white water, camping, and any place dry storage is needed. bills bags at NRS - Kayaking Gear Rafting Supplies and Boating Equipment

I experimented with using a 20-quart plastic storage container as a rack-trunk. I attached it to the rack with velcro tape through slits cut in the bottom and wrapped around plastic dowels that were inside-bottom.

It worked but I felt it might not be durable enough for long tours. It held up fine for a two-night excursion.


Unfortunately I only had this photo with my hi-vis pannier cover over the container. Note also the small container as a handlebar bag.

That is 98 liters. I have never been accused of being a lightweight bike tourist, but the sum of volumes of my Ortlieb panniers and rack top bag add up to 96 liters. Does this mean you are not using panniers? If you wanted to bump that up about 10 percent you could buy a S&S case and use that.

how about a BoB trailer and XL Portage* dry bag? you can buy a rack and rear panniers that fit over the trailer wheel too ..

* portage is what you do with a canoe, bag of gear on your back , canoe over your head, walking between bodies of water.

I use the kitty liter buckets all the time. Love them. Can't be beat quite frankly for the simplicity of building them and the price is completely unbeatable. I picked my buckets up at the local dump for nothing. They are tough and quite durable. They don't look like you spent a million dollars on them so people will have a tendency to leave them alone. A helpful tip, write USED on the back to help deter people from wanting to touch them.

That looks workable. My thought was to have a container large enough to fit my tent and bedding into, that's why it would need to be pretty large. The poles need about 25" of space to fit, so that's dictating length, and then the rest of the tent plus my bedding dictates the needed width and depth. I already have them in water resistant bags each, but I'd like them to be inside something else as well. I've just added this info to my OP as well.

The Ortlieb Rack Pack holds my sleeping bag, 2-person tent, lightweight ground cloth, Thermarest pad, and compressible pillow. The tent poles go under the bungees on the outside of the bag. Total weight is less than 10 lb.

See picture in post #3.

That is what I was thinking. It's the poles that are demanding such length, so I should place them outside of the bags. I'll take another look at that Ortlieb bag, thanks.

I agree with MSN, except you can do very well with about 1/2 of 96 L.
It's not car camping.

Get some waterproof panniers, put the mattress and sleeping bag in them and the tent on the back. If you are really worried about the tent getting wet while you are riding, put it in a plastic bag before you put it in the stuff sack (or after, if you don't mind a junkier look).

On some trips I strapped my tent pole bag to my rack. The medium to dark blue nylon bag sticking out the back in the photo is my tent pole bag, it was strapped on top of my rack.