The #Seatposthugger is a luggage carrier which is designed to hold the Brompton front carrier block and clamps onto your Brompton 31.8mm seatpost. With a suitable shim it might be useful on any other bicycle. You can order a conversion shim for 27.2mm posts as an option to this product.
Apart from the super fast putting your luggage on the bike and taking it off again it can be really advantageous for big wheel bikes as well. This because the bag goes up from the bottom of the carrier block instead of hanging down from the saddle. Especially for smaller riders mounting a saddle bag can be a pain as the distance between the saddle and the rear wheel is so small. Actually the bottom of the bag is a bit lower than the underside of the luggage block, because the bag is angled down, but you can compensate for that by changing the position on the seatpost.
Some dimensions for other bikes than Brompton: the clamp section requires a free seatpost length of 69mm. And the whole setup is 108 mm high measured at a 73 degrees seattube angle from the bottom of the luggage frame's foot up to the top of the clamp section measured on the center line. See the last two photos. With a bag included you need some 15 cm vertical space from the tyre up to the end of the 27.2 mm section of your seat post.
- brazed with 55% Silver and Tig fusion welded
- 4130 thin wall Chromoly tube and laser cut Domex 700 high strength steel plate sections (the real deal! it's amazing)
- including the front carrier block,
- low friction Hope clamp with quick release in Silver, black, orange, purple, blue or red
- the original seat post sleeve which I ream to size
- weight complete Model4: 328 gram
- weight additional aluminium conversion sleeve 31.8- 27.2 mm : 37 gram