We’re looking for that spark that will inspire someone to think about what they could do with their own bike, and the sort of bikes that do that for me are those that aren’t immediately what they seem. I like subtle, me.

Take this 1990 FLSTF Fat Boy for example. A prime example of a subtly modified original bike, except it isn’t. It is no more a Fat Boy than Kate Moss is, and the only things that were once attached to said motorcycle are the front end, tanks, dash and saddle. There is a slight question mark over why you’d want to make a Fat Boy from something that isn’t, but there is a simple answer to that. Chris wanted one. Or rather, Chris wanted another one.

It’s not his first Fat Boy, but the first one was the genuine article. He’d already put his money down on a 1990 Heritage Softail at the local Harley dealer, Easyriders in Southport, when Roger Kerwin asked whether he’d like to see the new catalogue. Silly question, really, but it created a big problem.

What the hell is that on the cover? Can I have it? Can I change my order?

It’s a Fat Boy, course you can have one, but no you can’t change your order because you bike’s on its way: its too late to change your mind now.

A desperate search ensued to get another dealer to take the new Heritage, but it was ultimately successful, and Chris found himself the extraordinarily happy owner of the very new, very different and quite probably the first Fat Boy in Manchester on the 1st August 1990. That first bike was not so very different a bike when compared to today’s and the family resemblance is obvious, but then, as now, it amounted to little more than a pair of solid wheels in a Heritage Softail and a unique front mudguard.

In that first year it was somewhat more distinctive for its “any colour as long as it’s grey” paint option, and for the fact that they’d never used the word “Boy” in a model designation before. We joked that it would start a new naming convention, with the Wide Boy, Old Boy etc. Others, egged on by the USAF-style tank badge, put two and two together and managed something approaching seventeen with the notion that it was named after the atomic bomb dropped on Japan at the end of the second world war, or an amalgamation of the names of the two: the Fat Man and the Little Boy. It made a great story, continues to do the rounds as a great urban myth but, in view of Harley’s sales to Japan, let’s be realistic.

Didn’t stop Chris calling his “Enola Gay” though - after the plane that dropped the second bomb, which was in turn named after the pilot’s mother. I bet she was dead chuffed.

That first bike got the tiniest of tiny Bates headlamps introduced to the tins at the top of the forks, barely big enough to fill the dent on the metal, in place of the goldfish bowl, and massive apes, and more than its fair share of paint job, including one which looked like the original bike had been ridden at speed through a vat of custard, all gloopy yellow blobs across the grey base colour. You might have seen it: you’d not have forgotten it. Seems a certain Bill Davidson didn’t after giving the Chris the prize for best custom at the 4th National HOG Rally at Ainsdale, and not only did he return to the states and give his own grey FatBoy the same headlamp treatmnent, but also picked Chris out in a crowd a couple of years back.

It was in that incarnation that Rich planned to shoot it for Supertwins magazine, but was out by a couple of days: the bike was stolen from Blackpool, which meant he got a curt response from Chris when he contacted him about shooting it.

And that might’ve been it. Chris got a Katana and messed about with that for a time, but had basically decided that he wasn’t going to do another proper custom É until he saw it: Zodiac’s “Wide-Tail” Softail-style frame. He had to have it. Think of the back tyre you could get in that. He got it and set about a new build from the ground up.

He wasn’t really aware that the frame came with a 38-degree rake but then he wasn’t looking at that end: if you think you recognise the angle, think V-Rod. The “Wide-Tail” frame comes with a suggestion to use forks with an additional four to eight inches - depending on the size of wheel and tyre to be used - but Chris wanted low as well as fat, and concentrated more on getting the back down to match - he’d used a White Brothers lowering kit on his previous Fat Boy, but went the high tech route this time with an adjustable system from Works Performance although left at its lowest setting, he reckons it might as well be a hardtail but it looks exactly as he wants it, which oddly is not as he originally intended. He may have been a big fan of that first fattie, and he may have got a Softail look-alike frame, but his intermediate years on a big Jap tempted him to use wheels and forks from a bike with a better reputation for brakes. Undoubtedly it wouldn’t have been grey, it wouldn’t have had the orange highlights and it would have been a damn sight easier to complete but just as the frame wooed him, so too did the rear wheel - one of W&F’s re-machined Fat Boy disk wheels. And that was the end of a high-tech Softail and the beginning of the Fat Boy that never was. Still, he didn’t scrap the idea of decent anchors and 4-pot PM callipers grips the single disks at either end of the bike that was always going to have enough power to give them some work to do.

Oh yes, the engine was always going to be a serious piece of kit to match the original power custom concept. The fact that Chris works for an official dealer - Bauer Millett in Manchester - didn’t blinker him to the potential of an off the shelf big-bore motor, and at the time of the decision they didn’t come much better recommended than a 97-inch Long Block S&S - 3 5/8 x 4 5/8 inches of long-stroke torque - so a conversation with the company that would become “Sparks” and the second major piece of the jigsaw was in hand.

There is never a better time to strip and check a motor than when it is brand new, and then it’s good to have a reliable set of spanners on hand. Chris called upon Kirk Herbert, his former service manager at Bauer Millett, currently service manager at Centurion, but then plying his trade at Just Harleys. It was deemed a sensible plan, especially as it was always going to be taken down anyway and handed to Jimmy Norman at Milwaukee Muscle for a bit of attention, but it didn’t take his level of expertise to identify a couple extraneous bolts rattling around inside the cases. Oops. Thankfully quality control is in another dimension these days.

Regardless of which factory an engine comes out of, if it is built on a production-line it will be built within tolerances. The age of the engine assembly plant will determine what those tolerances are, and the engine’s design will dictate what you can get away with, but while those tolerances are generally acceptable for a road-going engine, they are, by definition, not the precise measurements as specified on the original blueprints.

There are wonderful, colourful tales of pistons being matched to barrels in olden days, whereby a piston without rings was inserted into a barrel and its descent observed: if it stuck, it was too tight; if it plummeted to the bench it was too loose; but if it gently slid to the bottom, it was a match and went on to the next process, whereby the weight of that piston was compared to one from another successful combination until a match was made and the production process moved on. It sounds horrendously hit and miss but the end result was such that a lot of the reciprocating parts were properly balanced. The downside, so legend has it, is that on a hypothetical day - probably Friday if we are to give any credence to the story - the balance of the parts were used and as long as the piston fitted and didn’t jam in the bore it was deemed close enough, and if a bore was too tight for any piston, it was reamed out until it wasn’t, and the final fit was determined by careful running-in of the motor.

That’s one reason why race engines have always been entrusted to a different department where they are meticulously hand-assembled by craftsmen, and even though the difference between pistons and bores being churned out today is minimal, due to improvements in metal and machinery, it is still true today at the top end of competition.

Those days are now behind us, but there is still no substitute for a hand-assembled engine built by a master craftsman. Sadly, they don’t come cheap because it is a time consuming job, but you end up with a motor that is as good as it is possible to be. Such engines scarcely need running in because everything is exactly as it was designed to be, with no rough bits to smooth out, but it doesn’t necessarily mean you shouldn’t.

Anyway, the suspect bolts were removed and it was packed off to Milwaukee Muscle Machines for Jimmy to work his magic, and it was gone for a long time while he wheedled the potential for another 40% more power from the lump. Just a hand-balanced crank in a blueprinted bottom end would make for a much happier engine, but Jimmy is renowned for his head work as much as anything else so it will surprise no-one who knows him that the S&S heads have had a lot of his attention lavished on them. Between removing the original valve seats and refitting and recutting new ones, the ports were reprofiled - basically filled with weld and reshaped without having to worry much about the original shape. While it doesn’t pay to increase the inlet side too much unless you want a high spinning motor, and I’d guess you don’t, Jimmy significantly increased the size of the exhaust port, culminating in a two-and-a-half-inch oversized valve to clean out the spent gases quickly and efficiently. Is that big then? Damn right: a stock Evo exhaust is nearly an inch less across the diameter.

Doesn’t take much to say it, takes a long time to do it properly, and the end result is a motor that will flow 300 cubic feet / minute (cfm) compared to the stocker pushing 240, and the highest flowing heads that Jimmy has produced to date. If you have a moment, and gas flow characteristics rank high on your list of priorities, you’ll be all the more impressed to learn that that was measured at the modified ram jet manifold and not at the mouth of the port, which is the more common point.

Nice bit is that you’d never know it, looking at it from the outside, where the S&S legend remains undisturbed. Nor would you, really, by the exhaust note breaching Her Majesty’s peace far less than you’d expect through a pair of 2-inch headers breathing into stock silencers. Well, stock silencers that have been re-baffled to provide the right amount of back pressure without too much noise.

Keeping himself busy in the meantime, Chris set about tracking down all those bits that make the 1990 Fat Boy stand out from its successors. Little bits like the rocker spacers that show a hint of colour on an otherwise very plain finish motor, matched by a colour accent on the points and derby covers, and round the switch on the dash, and even within the distinctive logo that we all believe we now know so well. Easy enough: it’s Harley’s house colour and surely no problem ... isn’t it? Sure, it’s H-D’s favourite colour, but one-off first year models get an attention to detail that doesn’t often extend for a second term, as anyone looking for a set of orange-banded wheels off a Sturgis will be all-too aware. It’s not just about colour either: you don’t suppose those covers got machined by themselves did you? Standard on the first-born Fat Boy, and copied ever since.

And then there’s the leather trim that has remained unchanged, in the form of the laced seat skirt and the tank trim panel which softened the otherwise hard grey lines of the stark paint scheme.

The motor was finally ready to rock and roll and a sum of money, not dissimilar to the cost of a Fat Boy in itself, changed hands and the next stage of the build could begin. The motor was mated up to a stock box with a kicker conversion - to give Chris a bit of exercise just in case he was feeling a little lardy himself - behind stock transmission covers driving a stock belt on stock gearing: why fix it if it ain’t broke?

A sizable strip of steel cut and shut into the rear mudguard, obviously, to stand any chance of covering the 190/50-ZR17 tyre wrapped round the reworked wheel. It’s a long way from the current trend for 250+ tyres, but beneath a valanced mudguard it’s more than enough.

Those of you who are slapping significant slabs of rubber in your swing-arms, and wondering just how far out that primary will need to go if the tyre is going to clear the belt, will have already spotted a lack of spacers twixt crankcase and transmission, but that’s where technology was when this build started. I don’t think I’d lose any sleep if the passion for width had gone that far and no further, personally, but wherever there are boundaries, they’re gonna be pushed.

The engine was always expected to be a painstaking, time-consuming operation, but hopes were higher for the final assembly, until it went away to an unnamed company, in anticipation of an early phone call to say it was ready. But the phone call didn’t come. It didn’t come late either. It didn’t actually come at all until Chris started to really kick up a stink. How complicated could it be?

When it finally did return - way beyond its original deadline - it was due back at Milwaukee Muscle for a final fettle to take it from a guesstimated 125hp up to the 140 that is known to be lurking within - a final tweak of the exhaust, ignition and a ThunderJet kit in the carb would sort it - but Chris had been waiting for it for so long that it was time to put a few miles on it and get something back for his outlay, which is where we see it today. I get the impression that he’s in two minds as to whether to put it all behind him now, due in no small part to the frustrations of the final build, or to keep it and realise the original ambition of the fastest Fat Boy on the block.

He’s certainly got a price in his head as to what he’d part with it for, but I’m not absolutely certain how easily he’d find a final separation. Sitting in Bauer Millett’s showroom at £18k, it has had a few sniffs - mostly from people who haven’t seen the significance of the attention to detail paid in capturing the essence of that heavyweight custom that has always demanded the highest price - and he’s had to bite his tongue as potential purchasers have confided in him that they’d change this or that. They have been oblivious that they are talking to its proud father, and on a couple of occasions it’s been all he can do to stop himself advising them, in less than hushed tones, that they might be better off buying a stocker and producing their interpretation from that.

But that’s the way with customs.