“At present I carry two children to school by car, often picking up shopping on the way home. But the traffic is dreadful and I’m embarrassed to sit fuming in the car when alternatives exist. I saw the ‘Family’ bike at CYCLE 2002 – would this be a suitable bike for my regular school run?”

Hilary Johnson, Blackburn

The Family Bike features a fairly conventional step-thru frame with a number of bolt-on accessories to convert the basic machine into a commuter bike, child-carrier or domestic load-carrier, but it’s hardly a car replacement, and it exhibits a number of disturbing characteristics that make daily use impractical.

Unfortunately, carrying heavy and/or vulnerable loads atop conventional full-size bicycle wheels brings a number of problems.The primary one is stability at low speeds, made much worse in this case by the comparatively flexible step-thru frame. Another serious irritation with carrying a child over the front of the bike, is that the poor creature has to be lifted up, then threaded down through the gear and brake cables into the seat. In practice, most people would find this a terrible chore.

Other weaknesses with the Family include an unreliable stand (a really good stand is essential on a load-carrier) and a crude and rather inadequate derailleur gear system.

…All of these characteristics raise handling issues… the Family Bike is a rather unstable

There’s nothing wrong with the principle though. A cyclist can carry a considerable load (say 30kg) on the flat once they’ve expended a bit of energy accelerating the mass to a modest 10mph or so. At these lowish bicycle speeds, wind resistance is not a serious issue, tyre rolling resistance shouldn’t cause too much hindrance, and mechanical losses can effectively be ignored. So in practical terms, a power output of 100 watts or even less should suffice to keep you rolling, once underway. Stopping involves transforming the kinetic energy into heat, so you need decent brakes, and a load that’s high and/or at the extremities of the machine (see the Oxygen Atala, page 21) may cause handling problems.

On hills, the picture is rather different, because you’re now attempting to lift the mass against the pull of gravity as well as move it forwards, so the power requirement rises very rapidly. For example, if the same rider were to attempt to climb a 10% gradient at 10mph with the same bike and 30kg load, a power output of almost 700 watts would be needed – far in excess of most people’s capabilities.

In practice – assuming the bicycle has suitable gears – most of us climb hills a good deal more slowly.Thus, if our cyclist chooses instead to climb doggedly, expending a steady 100 watts, speed would drop to about 11/2mph, or rather less than walking pace.

Let’s take another look at the Family Bike, and imagine it fully loaded and tackling a hill.With two children and a pile of shopping on board, we have a number of problems: The bike will be moving slowly; the load is positioned high up; it’s mostly carried towards the extremities of the bike; and there’s the extra complication that the child on the front tends to rotate with the front wheel. All of these characteristics raise handling issues. There’s no escaping the fact that the Family Bike is a rather unstable machine – with a heavy load on board, hills would be a nightmare.To make matters worse, the minimum gear ratio of 36″ is much too high to tackle any serious gradient.

The 8-Freight

Let’s put our optimum criteria on a blank sheet of paper and see what we come up with:The best place for the load is in the centre of the bike and low down, so we need a long wheelbase machine, with smallish wheels to keep overall proportions within reasonable limits. Small wheels would also enable the bike to carry panniers at either end for extra capacity, without putting this extra load unreasonably high.

A number of multi-wheel options exist, such as the Cycles Maximus Trishaw, the Brox or the Christiania, but these are large and comparatively heavy machines for ordinary family use and in traffic they get stuck amongst the motorised traffic, putting you back to square one.

For a possible answer we must consult the admirable Mike Burrows. Designing a load-carrying machine for a local welder, Mike produced the 8- Freight – a very long (two-metre wheelbase!) bicycle with 20-inch wheels and an ultra- low well for freight, positioned in the centre of the machine.The 8- Freight couldn’t be more different to the Family Bike – it is not specifically designed as a child carrier, but with a bit of lateral thinking, I feel it fits the criteria rather well.

…Safety could hardly be improved upon… the children are positioned centrally in an effective steel cage…

This flexible load carrier is roomy enough to carry two child seats, one behind the other, plus a reasonable load of shopping in panniers, or one child plus extra shopping, or the full supermarket shop, child free.

Safety could hardly be improved upon – the cyclist has excellent all- round visibility and the children are positioned centrally in an effective steel cage.When stationary, the wide stand (again, centrally positioned) provides great stability, enabling the children to hop in and out unaided.The stand is apparently automatic too, descending with the aid of gas-filled struts.

Gearing rather depends on the sort of gradients the bike is likely to see, but brakes are low- maintenance hubs and the 8- Freight is also fitted with Burrow’s trademark mono-blade forks for easy maintenance. In practice, you could probably fix a puncture without removing the load, by swinging the stand down and pulling off the offending wheel.

At a claimed 18kg for the basic machine, weight is remarkably low for this sort of machine, and comfortably lighter than the 21-30kg Family.The sensible weight distribution would make the bike feel lighter too. Obviously a two-metre wheelbase brings problems of manoeuvrability, but unlike a trailer, the 8-Freight is no wider than a conventional bicycle and should be capable of threading through stationary traffic. Remember, we should really be comparing this concept with three- or four-wheeled vehicles, both powered and unpowered – not a conventional bicycle.

Mr Burrows is no power-assist enthusiast, preferring instead to design light, practical machines that can achieve a great deal with human power alone. However, a simple rugged motor such as the Heinzmann would suit the bike well, making this sort of transport practical even in the hilliest areas.

At £400-£700, the Family has the edge price-wise, but even at £975 (excluding any custom extras), the 8-Freight is by far the best option.