Building the cylonbros has been one of my favorite projects so far; and one in which I have learnt a lot.

I started out with a fairly standard Honda Bros (aka Honda Hawk)



I decided to put a linkage system in it, to run a CBR600 shock as the stocker was naffed.

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Access to gear at university allowed me to perform FEA on the custom link part (which had to be curved to avoid the swingarm) and simulate the link profile; which was 1.3x at top of stroke. The chain roller was required as the new linkage lifted the rear around 30mm, by design.

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The fuel pump had to be moved to accomodate the new shock, so I took the chance to switch to a vacuum pump model, which I could mount just at the top of the shock, thus reducing fuel line length. Also added was a mount for the shock’s remote reservoir.

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Some frame sliders added just in case…

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A new front end, from a ZXR250C, with renthal fatbars and custom risers, as well as custom mounts for the caliper, headlight, and mudguard.P1010476

A blinging throttle assembly which was machined from billet plate with 3D profiles.

Now things got a little more interesting with a tail section and exhaust rebuild. The headers were left stock, but replace with stainless copies at a later date.Cowl P1010502 P1010506 P1010512

I found a single seat unit to use, and designed a 3d model of what the tail would look like using. From there I could create an exhaust and wooden molds for the plastic work. The exhaust turned out really well, with twin perforated tubes in an oval container stuffed with muffler-packing it allows the throaty rumble of the v-twin to be heard, but not obnoxiously so.P1010521 P1010533 P1010535 P1010539

Next up, was the subframe. Because it is a single seater I could get away without much bulky support members, the muffler is part structural member, and partially supported by the subframe; a tail-tidy was fitted to the rear. Joining the exhaust was fairly simple, and wrapped with muffler wrap so it did not pass too much heat through to the under-seat components. P1010620 P1010627P1010629


The wooden molds were in 7 different bits, and after a bit of bogging to get the right shape I took vacuum forms off each. These forms are the outside of the tail section, as they are only thin I used CSM fibreglass to coat the inside of them; both to provide strength and to join them to one-another.P1010688 P1010685

After a bit of paint, it was job done. Well, almost, the tail light fills the gap between muffler exit and tail section. The seat was also re-foamed with a gel pad for comfort, and leather cover. It has a large number of high intensity LEDs driven in groups of fours by two ATtinys. Below are two gifs showing the characteristic cylon-scroller park lights, and some fancy hazards.

Cylonbros Hazards


I needed a new mudguard and as there was not space to put one around the shock/exhast I made a tyre hugger.

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I covered the tyre with tin foil, then CSM fibreglass, then fibreglass woven mat, and had a wooden jig to provide support where the mounting points would be. After it was trimmed/bogged/sanded it got a coat of matte black and installed.P1010795 P1010796 P1010798 P1010799

Whipped up some new headers, and got some parts powder coated, very happy with the work and color choice of metallica bronze. The sprocket cover is a custom part, which has proven popular with the guys at as I’ve sold them a few.

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Just one final job, remake the headlight based on a cylon raider (re-imagined series) with a split-face style opening to expose the HID headlight. It was supposed to have actuators to open and close it, but they all blew out their gearboxes and due to size constraints I couldn’t get any others in there without a massive redesign…

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So I got sidetracked and made some footpegs.

No doubt there is a few other smaller mods I missed out, but I got around to finishing off the headlight unit, complete with digital speedo and cylon-scroller eye. So now for a barrage of pictures and a video!P1020497 P1020498 P1020506 P1020507 P1020508 P1020510 P1020513 P1020517 P1020523 P1020524 P1020527 P1020543 P1020546 P1020547 P1020548 P1020549 P1020552 P1020553 P1020554