Unlike a tandem: a trailer-cycle can quickly be uncoupled so the lead cyclist can ride unencumbered, or coupled onto another bike. That’s neat when there isn’t money or space for lots of bikes and convenient when parents share responsibility for child care.
A trailer cycle, even a good one, is more bendy and not so stable as a tandem. So to avoid ‘the tail wagging the dog’ it’s recommended that the trailed rider be less than half the weight of their leader.
Also some types of bicycle should be avoided. Generally: if a bike can handle heavy luggage it can lead a trailer-cycle. With these two provisos: the control of better designs of trailer cycle is quite predictable and safe enough. Thus trailer cycles provide parents with a handy way to keep cycling with their children of 4 to 10 years old, when they’ve outgrown the childseat but lack the maturity to go solo.
Don’t call them trailer bikes. Besides the fact that bike implies two wheels, Trailerbike is a registered brand name for the trailer-cycles produced (until recently) by Isla Rowntree to the same design as the original “Rann trailer”.
Yes that’s another name for them, after Mr Rann, a custom-builder of bicycle frames who invented the trailer-cycle in the 1930s, in England. He made a lot more of these trailers and the design was much copied to satisfy the demands of the post-war cycling and baby-booms, and the name stuck right up to the 1980s.
Right from the start, Mr Rann deduced that the best handling for such a trailer is obtained by placing the pitch and turn pivots (that’s for up and down and steering movements) vertically above the lead cycle’s rear axle. This is achieved by hitching the trailer to the centre of a sturdy towing frame attached like a rear carrier (and often doing double duty as such) to the lead cycle.
The only manufacturer to improve upon the Rann concept is Burley. Their excellent (but costly) Piccollo trailer-cycle also has a towing carrier for the lead cycle and pivots vertically above the wheel. It differs by fixing the steer pivot to the carrier and the pitch pivot to the trailer rather than vice-versa.
This avoids the tendency of a traditional Rann to jackknife and flop over when reversing to park etc. Unfortunately you have to pay made-in-America prices for this excellent design. But if you want the best for your kids … and they hold a good resale value.
Sadly, the production of trailer-cycles (in any quantity) in the country of their invention was extinguished by the ubiquitous family car. When interest rekindled in family cycling, it was merely as an occasional leisure activity – something not worth spending a serious amount of money upon.
Unfortunately, parents had become much more protective of their young and demanded some adult-guided means of junior pedalling – so long as it didn’t cost much – and the 1990s Britain spawned a rash of alarmingly unsound inventions for simply hitching a kid’s bike up like a trailer!
In the 1980s some North American firms, notably Adams in Canada (Slipstream and Trail-A-Bike) chose a less costly way to make trailer-cycles, dispensing with the towing frame and coupling directly onto the lead cycle seatpost. This also appealed to (unknowing) consumers as a simple means of attachment. Increasing demand brought in Asian manufacturers and the last decade has seen a proliferation of cheap seatpost-fixing trailer-cycles.
Some seatpost hitchers are not too bad: where the pivot joints are a little way behind the seatpost and oriented so the turn pivot is vertical. Also check the size and firmness of these pivots. Some designs use rather small universal joints, some of which feel sloppy even before they’ve started wearing out. Sloppy pivots make a wobbly trailer.
However the worst designs use the seatpost as a turn pivot. The seatpost slopes backwards so the trailer leans outwards on corners, which feels wrong to both riders. Seatposts moreover can be made from rather thin aluminium alloy these days. And they’re designed to take a downward push, not various pulling and twisting actions.
It’s amazing what some people can ride (or accept as normal if they don’t know any better), but you’ve got to draw a line somewhere. There comes a point where it’s probably safer to let a six-year-old ride their own little bike than compromise the safety of both child and adult upon a combination that the latter can control only by dint of extreme concentration.
I reckon we’re well past that line or point when we get to the devices I briefly mentioned above, that attempt to save even the modest expense of a trailer-cycle by coupling two existing bicycles together! Cycle-Mate and Tandette both place the pitch pivot way behind the leading rear axle, which is much worse than in front of it, and use the trailed cycle headset as a turning pivot.
Not only does this off-vertical turn pivot make the trailer bank wrongly in corners (as I’ve already mentioned), but back-seat steering also interferes unpredictably with front seat control. The fittings used to couple the cycles add further flexibility to the combination.
One notable exception is the Linkit by Astell Leisure. This substantial piece of equipment locks out the trailed headset and provides a Rann/Burley-type link between the two bicycles. It handles as well if not better than many purpose-made trailer-cycles. Sadly, that couldn’t compete with cheap imports either, and is no longer made.
There is one further bike coupler that can almost be recommended: the Trailgator. It’s substantially made and does not suffer too badly from most of the defects exhibited by similar devices.