The Honda SL70 K0 is one of those bikes that lives in the margins of Honda’s history, built for just a brief period, small in capacity, and often overlooked next to the brand’s larger trail models. But when Andrew sent his Victorian-based K0 north to the Gold Coast, the brief wasn’t casual preservation. It was a ground-up restoration with selective upgrades, executed to a standard that would satisfy one of the most detail-oriented owners to roll through the doors of Purpose Built Moto. And the result is a retro-resto so good, it literally looks better than new.
Led by Tom Gilroy, the PBM team has built its reputation on custom fabrication and performance-driven redesigns. Lately, though, restorations have become a deliberate exercise in restraint. “This is a test I set myself to change styles, and shift gears into another way of thinking as we approach our projects,” Tom explains. After completing a Royal Enfield rebuild and a Honda Dax, the SL70 marked another step into factory-correct detail work, with room for subtle improvement.
Andrew’s connection to the bike runs deep. “Our rider Andrew has a long love affair with Honda Minibikes, as both he and his brother grew up on them,” Tom says. Now in his 60s, Andrew has been thinning out his full-size street bikes and returning to the machines that shaped his early riding years. The SL70 wasn’t destined to be a static showpiece either; he already owns a concourse example, so this restoration could lean into usability without compromising authenticity.
The starting point helped. “This bike started from a place that we are not often lucky enough to see, with a well-maintained machine, in OK running order, just showing its age (54 years),” Tom notes. But good wasn’t good enough. “From our first few conversations, I knew nothing but the absolute best was going to pass with this build.” That meant a full mechanical refresh, finish corrections throughout, and obsessive attention to factory detail.
The horizontal single was stripped and rebuilt using NOS Honda components. The carburettor was refurbished, with select parts chromed and polished. The cast-iron cylinder was finished in machine silver to tie in with vapour-blasted cases, maintaining OEM character while lifting overall presentation. It’s subtle work, but deliberate, nothing flashy, just correctly executed.
The external moving parts received the same treatment. Fork tubes were re-chromed and fitted with heavier springs, while the lowers, hubs and brake plates were polished. The factory rims were restored and re-chromed, then laced with stainless spokes. PBM sourced OEM rear shocks with slightly uprated springs, “because Andrew is not a child anymore (at least physically),” Tom adds. Controls were repaired to reverse previous damage, including correcting a drilled handlebar and reinstating the original 6V horn switch. The factory switch block was rebuilt internally and refinished with fresh paint to replicate the original printed markings.
Parts sourcing proved the most demanding phase. “One of the most challenging aspects of restoration on old and rare motorcycles is parts sourcing,” Tom says. The optional factory speedometer, unique to the K0 SL70, was non-negotiable. “Finding the factory optional speedometer would have been hard in 1985, but try it in 2025!” After two months of searching, Tom located both a used unit and a NOS example in its original Honda box. Andrew chose the untouched item. “I won’t disclose the price tag… but feel free to let your imagination run wild.”
Paint closed out the build. The frame was refinished in original Honda satin silver by Colourfuel in Sydney before final assembly began. For bodywork, Andrew selected Aquarius Blue, also known as Riviera, depending on the market. Despite the absence of reliable colour codes and with no viable US reference samples available, Colourfuel mixed a bespoke match from scratch.
The result is a crisp, period-correct blue with OEM-style detailing that completes a restoration defined by precision rather than excess. As Tom puts it, “That unique sound of the Honda minibike you only get from the horizontal cylinder motors” was the final confirmation on the test ride that the job had been done properly. It’s the kind of nostalgia that doesn’t need explaining.
[ Purpose Built Moto | Photography by Ninefivers ]