Local (non-London) store had three sizes, regular bumbag size, large hip bag, and messenger bag (lots of space, but no waist strap that I could see). All made with black tarp. Messenger was about £16 and bumbag and hip bag were £6 each.
Yea I noticed on my travels that if there is more than one of the stock then probably it's in most stores. Check the two in central (Charing X rd/Tottenham Court, and Covent Garden) if you don't have any luck. I'd be surprised if there are none in stock.
Heads up... TK Maxx has bags by BLC.
Local (non-London) store had three sizes, regular bumbag size, large hip bag, and messenger bag (lots of space, but no waist strap that I could see). All made with black tarp. Messenger was about £16 and bumbag and hip bag were £6 each.
This is the hip bag:
http://www.brownbreath.com/2017/04/10/review-n395-gravity-waistbag/
Insane for £6, wore it while walking today around the waist and it stayed tight and comfortable. Will try it on the bike tomorrow.