So I'm looking for luggage options for the rear rack on my Brompton. All I can find is the "Rack Sack." That's everything. It's hard to believe Brompton would be so short sighted as to design the rear rack with just one bag option. Is there anything else out there that could work?

You could probably use a different manufacturer's rack bag if it fit.

But I'd also recommend looking into getting the mounting block that screws into the Brommie's headtube, and getting the lightweight S-frame from Brompton that mounts on said mounting block.

From there, you can cobble together any kind of bag onto the S-frame that'll work. I fitted my $4 rummage sale bag in just that fashion in post #2 of this thread: https://www.bikeforums.net/folding-bi...l#post16093787

The neat thing about this arrangement is that the bag does not move as you turn the handlebars in either direction, which keeps a nice constant center of gravity. And the quick-release system for the S-frame/mounting block is very easy to use.

Ah, I didn't think of other ways of using the s-frame. Nice. I do have Brompton's folding basket, but I don't want to put anything fragile and expensive in it for fear of it just popping out on a rough bump. I've noticed the small wheels are a lot less forgiving than those on my other bike. Also, things that need to stay dry really shouldn't go in that basket.

The Brompton rack sack might be the best solution since Brompton designed it specifically to work with their bike and it is the only one. I'd just like a few options like they have for the front.

I use this on my BF. I like that I can leave it off unless I need it so I don't carry extra weight all the time. Unclips if I want to fold it and the frame fits inside my backpack (you can use a lot of different bags on it, you don't have to use theirs). CrossRack Bicycle Rack | Xootr Urban Transport

You can modify the brompton basket. Add a rolltop to it. Works great. Can not imagine using the B basket unmodifyed.

https://www.flickr.com/search/?text=...ket%20modifyed

I have an S type and also a basket for large loads but fine when empty it interferes with the brake levers a bit, so I tie the two handles together and that helps. When full this isn't an issue. Anyone else find this and have a better solution? That bag will hold an amazing amount of stuff without affecting the handling but it sure does slow you down in a headwind. As Bargain Guy said, I have made a couple of bags of different sizes which work fine for different loads and are both a little more aero. I also bought a cheap nylon bag for the Army Navy store and stiffened it with a back of 1/8 inch plexiglass to hang off the saddle. This is enough for light things and since stout winds are everyday here it doesn't slow the bike since it is behind it.

Is there something I am not getting here..the original post was luggage for the rear rack..most people have written about the front luggage options..
I have a rear bag by Axiom...which fits on a Brompton rear rack with 4 velcro straps..Easy to take the bag off in a few seconds..about 15 litres in all ..It has 2 side panniers that fold away but if you have large feet you might catch these..I believe the Topeak company make one similar...
The best thing I have found is simply to put a Carradice Nelson Longflap saddlebag straight on to the rear rack held on by 2 bungies ..or 3 ..about 25 litres plus..trouble is it needs to be full...

I vaguely recall some folks using the rear rack to support a backpack with the top of the backpack strapped to the saddle and seat post.

That's one of the benefits of the Crossrack. Puts the load behind your body and out of the wind =). My neighbor toured on a Brompton with a crossrack in the rear for their clothes and gear and a front rack frame with just the sleeping bag.tent lashed to it. Kept the front fairly narrow and aerodynamic and the wider load in the back.

Because the Brompton rear rack is folded Under as its Kickstand , in fold number One,
(L model it's .. mudguard roller and the 2 wheels on the rear frame portion)

you have to remove the bag on the rack to stand it on its folded under rear end.

Options: Large Carradice saddle bags.. on the seat back loops.. seatpost beam racks , or my favorite:

the Carry Freedom City, folding, Bike Trailer , with a Chariot ball elastomer and socket Hitch .

Heinz Stuke is one rider now on his decades long Bike tour Using a Brompton
with the back country sized back Pack standing on the rear rack + the B touring Front Bag.

You could do something like this - a stiff framed backpack hung over a seatpost extension rack.

^^^ Water resistant Zippers on the back pocket of the front Bags?



Here is a Nitto Made rack for those who bought the non rack Bromptons, then changed their mind..

https://www.perennialcycle.com/produc...idcategory=166





....

Video: Backpacks on Bromptons @ The Path Less Pedaled

that a Karrimor rear-saddle bag? my red one died of sun exposure..

I just want to mention if you buy a variety of sizes of back packs,depending on what you are doing you can choose the right one to suit the trip/day.Best places to find some good deals is a local thrift shop instead of spending a small fortune.Also if you rig the pack right you can still fold the rear wheel under the bike with out removing the pack.

Or army-dump-shops and army surplus web-shops

How can you do that without hanging too much weight on the seat post?

Quantify "too much"?... note # 17, the beam rack is clamped on low, the seat post is steel.

Simple,don't hang so much weight on the post in your backpack to begin with. Get used to packing light, as they say "take half as much stuff and twice as much money." You would be surprised how much you don't need to take with you.My Brompton in shopping cart mode can handle a shopping bag or my largest pack hanging on the seat back with 20+lb.I leave the handle bars up as a counter balance and it will stand alone with out any help.If you tend to pack a bit more than I do then put the heavy stuff up front on the luggage frame.
Besides don't forget once you get into the saddle for a days ride how much is weight is that seat post dealing with then?

Edit: I forgot to mention if you are worried about leaving a heavy pack hanging for some time on the back of the seat post than just lower the seat post until the pack is resting on the ground.

I'm using a 1.5" PVC tube that holds my tent poles, instead of a wood dowel that is only a wood dowel. I just made it so I don't have any miles on it yet, but there's no reason it shouldn't work.

Extended luggage should better be covered with a combination of fluorescent and reflective material, especially in the dark.

Fly a red flag, that is what we do when hauling lumber that is longer than the truck-bed, so it sticks out the back.