deBolex Engineering CB750 'YKB'
By Ross Sharp - 06 Sep 16
Mind reading isn't a skill that many people master. Some come close especially when working with a person whose ideas tend to translate straight to a material, bypassing the mouth altogether. For proof just ask Des at deBolex Engineering, he often finds himself staring at Calum hoping that the genius inside that petite noggin will spill out onto a piece of paper, to give a clue as to how a particular component should be made.
Thankfully some customers turn up with such a clear brief that the guess work for all parties is greatly reduced. That's not to say that a custom builder's workload will be alleviated, just that budget and endeavour can be channelled into fit-and-finish rather than disappearing into stool time. And no, not a workshop break to drop a deuce but the hours that can be eaten up with gazing at a problem while BAD (Brain Aided Design) offers solutions to problems.
The owner of this 2000 Honda CB750F2n is a specific, detail man called James. He arrived at the deBolex HQ in South London with a definitive shopping list for him and Calum to trawl through and draw-up a build sheet. The outline brief though was simple - CB750, spoked wheels on Firestones, a brat seat and blue paint.
If you're new to Bike Shed, welcome. Where the hell have you been? And if you haven't heard of deBolex please email us requesting a slap on the wrist and an eye test. Rather than blow anymore smoke up Calum's tailpipe check his portfolio of builds via the links below. Suffice to say that for a bike to even roll into the workshop the owner must expect that it's not going to roll out again unless the most fastidious of work has been carried out. The deBolex motif doesn't get painted onto nearly-rans. Expect eat your dinner off it engine cases and neatness that would have a Danish interior designer feeling ashamed of themselves.
Click on gallery image to enlarge the detail
With a suitable platform to display his craftsmanship upholstery wizard Des knocked-up the dark blue leather saddle. We reckon he must cheat, the sewing machine is just an elaborate cover for a CNC Seat Stitcher 5000 hidden out back. Not wanting to be outdone Calum fabricated a minimal battery box from aluminium, just big enough for the latest generation of Li-Po powerpacks and the guts of a new wiring harness. Size zero electrical man Will Valentine from London Motorcycle Wiring (he's tall, it's the looms he makes that are tiny) did the honours with persuading the necessary relays and fuses to fit inside the rather compact box, which is accessible quickly thanks to a simple two bolt fastening. Very neat indeed.
With the back sorted attention turned toward the front. Chunky, cartoon proportioned 16" Firestones would be enough to visually balance an upside-down fork and James wanted decent braking and proper suspenders. Grafting-on a modern front end might seem simple coz everyone's done it but as is always the case, execution is everything. After some head scratching and a few late nights the late-model Yamaha R1 setup fitted looks like it was meant for the bike. A simple hand-rolled mudguard is supported by even simpler stainless brackets, but again, a super-neat job has been done.
James liked the classy finish of Maxton's twinshocks. Their thin coil springs and machined adjusters not only match the effort and standard elsewhere on the build but they're specific to the bike, James' riding style and of course his weight. Plus it's always good to support local business. Maxton have been manufacturing suspension in Cheshire since 1971 and they're a dedicated bunch. OK, Croydon isn't all that close to Cheshire but England is a pretty tiny place really.
With a set of Renthal Fatbars upfront it seemed like a Best of British whitewash but then Calum messed it all up and started ordering foreign components. Tut, tut. But! With German outfit Motogadget doing such an awesome job of making speedos and switches you'd be hard pushed to look elsewhere. A simple all-in-one speedo sits above a brushed stainless headlight and basic electrical functions controlled by thumb operated, rubberised M-gadget buttons, all wired in by Will.
A little further across the map and Italian peg and lever maestros Tarozzi provided a brace of machined rearsets and pillion pegs. Perfectly knurled and rumbled to a matt finish. But then things went super-foreign. Calum likes converting clutches to hydraulic actuation, for smoothness and a lighter pull. Taiwanese brake experts Frando produce a kit making this possible with a ridiculously small slave cylinder operating the original Honda clutch arm. Matching levers and master cylinders are also from Frando and they offer a silky, quality feel.
The engine didn't escape Calum's attention either. The donor bike had covered just 12,000 miles and had been lavished with maintenance over the last 16 years so there was no point cracking it open. Sealed and bunged-up properly Calum lightly blasted the whole unit before coating in gloss high-temp paint. Outer gaskets were changed and obviously it's had the most thorough of services.
With pig iron parts swapped for more modern alloys overall weight is considerably lower than stock so there wasn't a need for trying to squeeze more power from the 750 four-banger, just the usual improvements in breathing. K&N pods and a near straight-through exhaust. Four of them as it happens. James was adamant he wanted four separate exhausts and Calum likes to show-off his stainless welding, a match made in heaven. There's a tiny baffle welded into each branch, just to take the edge off but there's still enough rasp to hear the thing coming. From the next post code. As usual deBolex bikes visit the rollers for a proper setup before hitting the streets. Calum will always puts some miles under the belt of a fresh build to make sure any teething problems happen to him and not the customer. Apparently. We just think he likes riding the fruits of his labour - can you blame him.
Thought I'd forgotten the tank didn't you. Nope. The beefy front end needed a little more space to turn and achieve full lock so a slightly more dainty tank from a CB550 has been adapted to fit. James is a cultured man so matt black with some stripes wasn't going to cut the mustard.
The paintwork was inspired by the work of French artist Yves Klein. His heavy use of aquamarine blue began at his debut, Monochrome Works: The Blue Epoch and continued into his later performance art exhibition, Anthropometry. The latter involved using the bodies of naked women as a “living paintbrushes" and he would famously sign his invitations to the opening with an anonymous handprint. Calum has a top-level paint facility so matching the blue pigment wasn't too taxing. What took a bit of time was perfecting the hand print, using the same method as kid's play school art, daub paint on a palm and slap it on. As you can imagine not much slapping occurred, apparently many, many attempts were made and from here it looks like they got it right.
But it's not just from here it looks right. The deBolex YKB debuted at Bike Shed Paris 2016 alongside a dazzling array of consummate builds, and I'm not just talking about the rest of the room. 2016 has turned out to be the seminal year for deBolex where they've stepped up from being an accomplished custom workshop to a globally acknowledged brand. No surprise then that customers like James are over the moon when Calum and Des agree to work on their project.
Oh OK, just a little bit more smoke then.
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Stunning images by Autohouse London shot at Shoreditch Studios
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