From my very first days of owning a Brompton I scoured the catalogues looking for desirable accessories that could turn a promising piece of ironmongery into a really useful piece of equipment. Eazy-wheels gave shopping tro l l ey roll-ability, while the B-Bag seemed to offer a defence against baggage handlers, but where was the rucksack? Surely someone, somewhere would produce a practical rucksack. But I never found one.

And then Brompton produced the titanium bikes, and the urge to upgrade got the better of me. I bought an S2L-X.This much lighter machine simply cried out to be carried, and as I couldn’t buy a rucksack to carry the Brompton, I decided to make one myself instead.

Designing a rucksack from scratch is a difficult process. Making one is virtually impossible. So the first step was to find an existing model that could be easily adapted to suit. Conventional rucksacks with their internal frames had little to offer and for a while I was stumped.Then came the breakthrough. I was looking for a frame that would carry a precious cargo weighing about 11kg.What other precious cargo came in that sort of size? Yes, children!! Very quickly I found the perfect rucksack in the form of the Vaude ‘Jolly Light’ Childcarrier.

The Vaude Child Carrier is a really excellent piece of kit. But all that I needed from it was the frame. Extracting that could not have been simpler.All I had to do was remove two bolts and undo a couple of straps.The rucksack frame was well capable of supporting the Brompton, but the next challenge was how to get them to mate  together.After much head scratching I finally concluded that the base of the folded  Brompton needed to be flattened in some way, and the most logical way to do that was to fit a rear rack. I then needed to flatten the rucksack base, and the best way to do that was to attach a simple plywood plate.The rack would then sit on the base just like books on a shelf.

…if a rucksack hangs from your shoulders… you will soon have back problems…

At this point I probably need to get a bit technical. Modern rucksacks do not hang from your shoulders. If that happens, the weight will be taken by your backbone and soon you will have back problems.A well designed rucksack takes the weight and transfers it to your pelvis using a hip belt. The Vaude is an excellent frame and does this brilliantly. Its balance is very good, but because the centre of mass of the bike is a fair way behind you, there is a moment to be balanced and that is done by the shoulder straps. So there will be a significant pull on the straps, but it will be backwards rather than downwards.

The rucksack base plate is very simple to make and fit. It consists of a piece of 10mm plywood, 36cm by 16cm. Cut a 40mm diameter hole centrally through it, 4cm in from the left-hand side. Now place the Brompton onto the plate with the seat stem located in the hole and fit two plastic blocks (the type used for self-assembly furniture) inside the frame to stop it sliding off. If you have Eazy-wheels fitted to your rack, then you will need to cut out a couple of notches to accommodate them too.The plate is then attached to the frame using 15mm copper pipe saddle clips. A coat of paint probably helps it to look a bit less like a DIY job at this stage.

In use, the Brompton is placed on the base plate, locating by the plastic blocks and the saddle stem passing through the hole.There are already two buckles at the top of the frame, and I use an old trouser belt which winds around the bicycle frame and can be drawn up reasonably tight with the buckles.The weight of the bike is carried by the base plate; this top strap is simply to stop it falling backwards.

Practical?

My bike weighs about 11.5kg, and the rucksack 1.5kg, making 13kg (29lb). If you can carry 13kg, the next question is whether 13kg of Brompton is any more difficult to manage than a normal 13kg rucksack! To find the answers I met up with Jo in Dorset. Jo, now retired, is a fit lady and had just returned from walking the Dales Way. Normally she carries a pack weighing 7kg (15lb), so this was a good test.We hiked for 41/2 miles along the Corton Ridge, the inland section of the South West Coast Path by the Hardy Monument. Jo remarked that it was more comfortable than she had expected.

I am actually quite a fit walker and often carry heavy rucksacks, so 13kg should be no problem. S tarting at Rhossili in South Wales, I rode the six miles to Port Eynon and then backpacked the bike back along seven miles of glorious limestone coast. C a rrying food and drink was overcome by using Lowepro Street & Field packs fixed to my waistbelt, which worked perfectly. Other items can be hung or fixed to the bike frame using velcro, clips or straps.The saddlebag that holds the Brompton cover is excellent for odds and ends.

The bike can be protected and disguised simply by fitting the Brompton cover.You will need to cut two one-inch vertical slots through the cloth to accommodate the strap, but it works very well.With the cover in place passers-by have no idea what you are carrying – only that it’s large! The bike proved to be just as easy to carry as a conventional rucksack, but I would recommend using walking poles. My intention is to use the bike to climb hills and then descend by another route.Typically, about ten miles on foot, then cycle back to the start!

A to B 54 – June 2006