TRIUMPH CRK CAFÉ RACER Nutters sorts out some wiring…
A change of plan means with the spraying of the CRK 1200 being brought forward, some electrical challenges can be met head on by Nutters, with mixed results!
Electrical circuitry is simple, yes? Join up the wires between a lamp and a battery and, hey presto! illumination is provided. Or so I thought, with distant memories from soldering tiny nickel-silver models in my school days barely helping to meet the challenge I’d presented myself with the CRK 1200 Triumph project.
If you’ve seen the first two parts of the project in CMM, you should be aware that I’d had the 24-year-old 1200 Trophy tourer stripped to its bare chassis, then cut off the rear sub-frame and replaced it with the CRK version that bolts and pins into the remaining stubs.
I’d sourced a handlebar kit that bolted onto the top yoke, and found a suitable headlamp from my spares. Ian Saxcoburg, who runs Café Racer Kits from the Isle of Wight, has experience as a design engineer in the nautical world,
and six or so years ago decided to combine this with his enthusiasm for building special motorcycles by offering bolt-on kits to convert cheap-to-source donor machines, such as Honda’s CX500 V-twin and early Hinckley Triumphs, into sassy café racers. Most of the components that Ian has designed are sourced on the island and are mailed as sub-assemblies, each of which has a descriptive chapter in the associated assembly manual.
The first box to arrive contained the replacement sub-frame and an oil-cooler bypass pipe, followed by another with the footrest hangers, rear brake master cylinder. Then another came with the under-seat tray for electrical components and the rear lamp assembly. Our postie was getting the hang of this by now, and recognised the CRK logo on the parcel with the headlamp brackets, and the next with the basics of the new electrical system.
By now I had a good idea of how my CRK 1200 should look, and rather than get cracking with assembling the complete electrical system as part of the dry build, thoughts of what the colour scheme might be started to gel in my mind. Ian’s demonstrator, which I’d ridden last year on the island and provided the inspiration for this project, featured an eggshell black frame, silver-lacquered engine with black detailing, and a maroon and silver tank and side panels, complemented by a trim, hipster-ish seat. Wheels were classic style with spokes and aluminium-alloy rims fitted with chunky adventure tyres. It looked a treat.
I figured that the 1180cc four-cylinder 16-valve six-speed engine, hugely impressive in appearance and mightily lusty and smooth in performance, could benefit from a finish that would diminish its apparent bulk. So I reckoned it needed to be painted black so that details like the
covers can be highlighted, along with stainless fixing bolts. Cherry metallic red for the fuel tank and side panels with contrasting black stripes and gold lining, like a 1978 Bonneville, seemed to me like the best option. I know that Steve Coker, down the road in my home town in Kent, will do a great job.
I’ve brought forward this decision because the idea of a complete and long-winded dry build before a re-strip for painting has been abandoned.
I’d bitten the bullet and booked the engine in for a session at Soda Blasters at Knockholt in Kent which specialises in cleaning all manner of automotive equipment, from small parts to complete car bodies. The guys there use a form of sodium bicarbonate (the same as baking powder) that when its granules are projected at a metal component ‘explode’, or so they say, in a way that removes surface corrosion without affecting the underlying metal, unlike grit abrasion or aqua blasting. I’d had the Honda 650 Bros engine cleaned this way, and castings came clean and smooth but without the surreal ‘better than new’ look that the aqua process gives. It’s also safer to use with a complete engine than these processes because there are no abrasive particles that can so easily damage the internals.
So all that’s needed is for the various apertures, such as the intake and exhaust ports, oil and coolant junctions to be blanked off with rubber plugs and sealed with duct tape. These have been bought from a website along with larger ones for the starter motor, generator (mounted above the gearbox) and coolant pump.
Before removing the engine from the frame, I checked how the various underseat components fitted into the sub-frame, which included the battery box and the rear seat mounts. This inevitably drew me into wondering how the new electrics would look, so I emptied the packaging with the C-box components and studied the instructions. Ian at CRK has also produced a video that shows how the system works and is assembled.
The clever bit is unlike a conventional wiring loom in which connections run back and forth from various components such as the ignition and handlebar switches, there are two small sealed digital boxes, one located under the seat and the other in the headlamp, that communicate with each other through two cables, one for power and the other for data. So, for example, there is no physical connection between the starter button on the right console and the starter relay. Instead, touching the button sends a signal to the front box, which communicates with the rear box which transmits power to the relay. Inspiration for the project: Ian Saxcoburg’s 1200 four.
Likewise, the turn signals require a touch for on and off, and the same for the main and dipped headlamp beams. The upshot is that there’s much less wiring, and what there is, apart from the direct lighting connections, requires much thinner wires that can be hidden more easily. It’s an approach that has been introduced by car and motorcycle manufacturers over the past decade or so, and more recently by suppliers to the custom bike scene.
So much for the theory: with the engine booked in for its soda blasting after Easter, and the remainder of the chassis for a respray about the same time, I decided to start work on the electrics and turned to the pages in the CRK manual, only to find that they referred to how to adapt the OE wiring. Ian at CRK reminded me that he had a separate area on his website with the new wiring diagram and a video showing the process of mounting the rear C-box on a plate with the ignition unit and the starter relay and connecting them with a junction box. For the uninitiated it takes an act of faith to follow the instruction to snip off the multi-pin plug and prepare the multi-core copper wires. Ian recommends that where wires need to be spliced together, rather than use a plug connector they be soldered and insulated with heat-shrink tubing.
Fine, except that my old soldering iron was too large for such delicate jobs: as fast as I soldered a joint it would overheat and melt the insulation with the risk of a dry joint. Ian suggested a call to Towzatronics, which offers custom motorcycle wiring services and a range of electrical components and tools. Towza, who runs the show, is less keen on soldered joints for the very reason I was encountering and finds that crimped connectors are satisfactory. But I persevered, and a more modern soldering iron kit, a box of shrink sleeves and a heat gun arrived in the next post, along with wiring and connectors. There’s logic to wiring diagrams but the ways in which the colours of the insulation are used can be confusing. But perseverance will pay off. The section of the bike’s system around the ignition unit and the starter as detailed in the C-box wiring diagram is straightforward and I
completed it without any drama. The wiring for the instruments is another matter. In the CRK conversion, the Trophy’s speedo and tacho are retained along with the wiring for the four instrument illuminating lamps and the six warning lamps for the left and right indicators, the gearbox neutral lamp, main beam, coolant temperature and oil pressure. These are fitted into individual consoles mounted on a plate that is bolted to the top yoke, all of which were shipped in another box. These lamps are lightemitting diodes (LEDS) in various colours, and come with a pair of thin connecting wires. I separated the original wires and set about connecting them with soldered joints. Two I wired directly to the LEDS, thinking that this might simplify the arrangement.
But the LED wires were tiny and even the new adjustable soldering iron was too large and hot to achieve a neat joint. The process requires each of the copper wires to be tinned with a little solder so that when they are connected it should take just a touch of the iron to make the joint firm. Practice eventually resulted in a set of firm joints, but I wasn’t going to wait until the wiring loom was complete to test them, so I used the new sealed battery (that arrived in yet another mailed parcel) to test the circuits. Two of the lamps didn’t work. Why? They were connected. I first thought the LEDS were at fault and asked for replacements that arrived from CRK a day later.
They worked, but only one way and not when the connections were reversed. But there was nothing marked on the lamps to show which way. So it was back to the drawing board and some deep concentration. The ‘failed’ lamps were reconnected, and referring again to the diagram I noticed that some of the connections (for neutral, oil pressure and water temp) don’t go to earth.
I reconnected everything, noting how the nine wires (one being for the revs signal to the tacho) would be attached to the front C-box and fitted them into a pair of junction connectors. This also required the eight positive wires, which would be connected to the battery via the ignition switch to be spliced with a series of soldered and insulated connections, as were the eight earth wires. A final circuit check showed that everything was working – phew – and I could store the instruments and the ignition circuit plate for later use. The satisfaction in reaching this goal was overwhelming, and provided the confidence to get ahead with the remainder of the project.
Those experienced in these matters will no doubt be chuckling, and I have to say that I wondered why I didn’t take up Ian’s suggestion of having the loom made by a specialist. But that’s too easy, and we don’t get involved with these activities just to then throw money at the challenge. Before the engine goes off for cleaning and respraying there’s the matter of how to handle the lump when moving it to the cleaners and the spray shop without knocking the corners off. The engine stand is fine for rotating the unit but the whole assembly is awkward to get into a van. The Bros V-twin was tricky enough, but the Triumph engine seems to be almost twice the weight. Gerry, who provided the angle-grinder that cut the sub-frame off, says he’s going to bring his compact engine lift. That’s a start then!