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three's a crowd

an elderly customer of mine owns a tricycle. and the tricycle she owns currently isn't the first one, it's her second. and it's exactly the same model as the first except it's blue as opposed to green and the box on the back is black not white. this box, while ostensibly large enough to cart a whole heap of stuff, can't actually do that because it is already weighing the trike in another way - it has a car battery in it.

the purpose behind this apparently strange state of affairs is that it's an electric trike that can be pedalled by human interaction, but the motor can kick in if the going gets tough or, indeed, steep. and it is quite a clever piece of engineering if you are willing to accept the fact that you are always lugging around a car battery if the motor isn't. unfortunately (or otherwise), i cannot remember the name of the manufacturer, but in the six or seven years that separate the green trike from the blue trike, they seem to have learned nothing about simplicity of design. and i am of the opinion that simplicity maketh the bike (which is why i take some exception to hydraulic discs, hydraulic suspension and electronic gear systems).

allow me to bore you with the mechanical setup of this tricycle: the electric motor, which closely resembles a car starter motor, is slung underneath the trike's downtube and is connected to the chainset by (surprisingly) a chain and a clutch arrangement that allows the bike to be pedalled when the motor is not driving. the motor is held in place by adjustable brackets to allow chain tensioning. the aforementioned chainset is connected to a sturmey-archer three speed gear that is, in itself, then attached to the rear axle by means of yet another short chain. the sturmey hubgear is bolted into a pair of dropout replicas that allow it to be moved forward and aft depending on whether the main drivechain needs tensioning or loosening. as you can infer, the sturmey is not built into a wheel but in the form of a standalone unit. as such, it has two sprockets, one receiving the chain from the chainset and one connecting the short chain to a sprocket on the rear axle. this is a similar rear setup as that used on pashley trikes.

now, the original green machine developed some apparent gear slippage after about four or so years of use that was originally attributed to the hub gear. since sturmeys are generally fairly easy to adjust, said adjustments were carried out, but to no obvious avail - every time it was necessary to put a bit more pressure on the pedals to get up an incline, the gear would slip. adjustment of the sturmey was made physically harder by the fact that it was sited behind the seatpost, underneath the battery carrier. and removing the battery and box simply to adjust the gearing was not a particularly inviting procedure. unfortunately too, the trike was so heavy that it was necessay to make some arrangement to jack up the rear to gain alternative access.

now i've been used to adjusting sturmey gears for many a long year, and have rarely been defeated in this procedure, but i was most definitely being defeated by this one (i've even completely dismantled a sturmey hub in the past, though i wouldn't recommend it - and with today's labour charges, it's more economical to replace a unit than it is to attempt repair). they do, however, have a remarkable record for longevity.

it was while scrabbling about underneath this tricycle that dawned that a possible reason for apparent gear slippage was not the sturmey unit, but chain slack, since the principal drive chain had that 'droopy' look about it. and this was when things just started to go from bad to worse. the sturmey unit could be easily slid rearward to take up the chain slack, but in so doing, slackened off the short piece of chain connecting to the rear axle. and removing a link from this shorter chain, made the chain just too short to be reconnected. so what if a link were to be removed from the main chain and the sturmey slid forward? same problem, but this time with the longer piece of chain. and still the gears appeared to slip when pedalling hard.

by this time, it is more than possible that the internal parts of the sturmey had been been damaged through this mechanical problem, and the decision was taken to purchase a replacement unit. however, replacing the gear unit would not fix the chain tension, and i could find no logical solution to this and resorted to the cycling equivalent of rtfm, and phoned the manufacturer.

"oh, that's easy" said the manufacturer. "undo the four bolts holding the rear axle in place, and slide the axle backwards." being a total chump, i hadn't even thought of this, since the stated bolts appeared to only connect the axle to the frame, with no apparent adjustment built in. it turned out that the adjustability was created underneath the frame, not on the top, so unless you were lying directly under the rear section of the frame, this stayed well hidden. however, this turned out to be the major failing of the whole system. since the adjustability along with retaining bolts was on the underside of a steel frame that had been ridden for several years through large quantities of agricultural 'road coverings', winter salt and grit, and the ever present 'salt sea air', corrosion had taken its toll. it was well nigh impossible to move any of the bolts or the nylock nuts affixed to the underside. and because of their positioning on the bike, it was wholly impractical to gain access with a saw or grinder. so my customer had to live with the problem for a few more months while awaiting delivery of a new trike (the blue one). she is fortunate to be of comfortbale financial means, because one of these machines comes close to 1500 by the time it has been delivered to islay.

on being now made aware of the nature of their method of chain tensioning, i phoned them yet again to suggest that all could be made a deal more practical if they fitted an eccentric bottom bracket similar to that used on tandems. this would not only make chain tensioning a lot simpler, (this method involves undoing two bolts clamping a slotted bb shell, and rotating the eccentric forward or back as necessary) but would have moved the adjustment area to a much more convenient and accessible area of the trike. their answer? "but we don't do that. it's always been like that."

far be it for me to tell someone how they should run their business by making a design change to an apparently successful product, but in geographical areas such as islay, where my cycle maintenance does not have, nor can afford, the facilities available on the mainland, it would have been nice to think that such could be taken into account at the design stage, to make the trikes more self-sufficient and lower maintenance. and it strikes me that the folks purchasing a tricycle of this design, where an electric motor can take over the duties of propulsion, are somewhat unlikely to be the sort of owners who could physically carry out much preventative maintenance of their own.

so now that the new trike is here, i have instigated a three monthly maintenance cycle which involves me removing the nylock nuts completely and removing the bolts from their slots before plastering them with grease and re-affixing them to the frame. this way, when it eventually becomes time to make that inevitable chain adjustment, all will be sweetness and light.

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this website is named after graeme obree's championship winning 'old faithful' built using bits from a defunct washing machine

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as always, if you have any comments on this nonsense, please feel free to e-mail and thanks for reading.

this column appears, as regular as clockwork on this website every two weeks. (ok so i lied) sometimes there are bits added in between times, but it all adds to the excitement.

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