This wickedly cool creation comes from Billy and the team at Eval Motorcycles, dubbed Upheval. Words: Kris Hodgson, Photography: Knackers BDP

If you haven’t heard of Eval Motorcycles, then let this motorcycle be your introduction. Affectionately known as Upheval, it was built for the Mooneyes Show in Japan and showcases the kind of bespoke design prowess that Billy and his team are capable of.

Eval Motorcycles - Upheval

Upheval, a 1986 Sportster 883 based custom with Paughco frame

Technically this is based on a 1986 Harley-Davidson Sportster 883, with Billy purchasing the engine itself in a Paughco frame in 2016 for $2500, admitting “I’ve always had a vision of building an Iron Head Sporty land speed racer styled bike and at the time this was the closest thing. It simply turned up that week at my shop as the guy needed to offload it.”

Eval Motorcycles - Upheval

Eval Motorcycles – Upheval

With the relatively modest power on offer from the standard 883 powerplant Billy had it bored to 1000cc, with the addition of roller bearings, shot peened conrods, ceramic coated pistons, Andrews V6 Cams and the standard head ported, polished and flow benched. A front mounted oil tank features copper hard lines, while compression is boosted to 10.5:1 from the original 9:1 ratio.

Eval Motorcycles - Upheval

Eval Motorcycles one-piece header assembly with straight through pipe and custom inlet manifold

The ignition system powering Upheval is a Daytona Daytec, with velocity stacks and a custom Eval downdraft Weber alloy manifold, proudly displayed off the side of the bike. These are matched by a bespoke Eval one-piece wide diameter speedway-styled header unit with straight through pipe, promising the bark to match this bike’s impressive looks.

The standard four-speed gearbox is retained, with a quaint but stylish stick shift mounted to the left in front of the tank. Final drive remains chain, with an O-ring item fitted.

Eval Motorcycles - Upheval

Left hand side hand shifter, custom front oil tank

Eval Motorcycles did the engine and clutch rebuild, with the machining done by Powerhouse Engines, with special thanks to John Pilla and Steve Campbell.

The Paughco frame was even more heavily modified than the engine, being completely modified by Billy and the team, including a telescopic seat post, axle sliders, and 50 individual CNC plasma cut bracket mounts and modifications. It was blasted in house and repainted.

Eval Motorcycles - Upheval

Upheval has a rigid rear end thanks to the modified Paughco frame, with custom rear controls, and a damper rod in the seat mount for comfort

The rear end is obviously rigid, while a girder springer system was designed by Billy and Joel, using the compression and rebound springs from a 1951 Ariel 500 and comprising 146 individual hand-made pieces. It’s a stunning set-up, although rather understated painted in the same black as the frame, apart from the gold and silver details.

It does serve to highlight the awesome front wheel which Billy explains was a special order hub with Paucgho rim, “I had this full spool unbraked front hub make in the USA to replicate the early Harley Star hub design,” and it certainly offers a streamlined front end.

Eval Motorcycles - Upheval

The rear wheel is a 16in wheel with a 5in tyre, and is originally a Sportster item. The front is a custom hub from America to match with a Paughco rim and is a 21in item.

The rear wheel on the other hand is a standard item from a Harley Ironhead Sportster, with both featuring 40 steel spokes. The front is a narrow 2.15 x 21in, with a 3.00 x 16in rear, featuring an Avon Speedmaster front tyre and an oversize 5.00 x 16in rear ‘Deluxe’.

Taking care of all braking duties is a matching Sportster drum brake, with all the linkages made in-house to suit.


Suzuki 2022


While this includes most of the bigger ticket items on this custom build, it’s in the details and smaller parts that the true artistry and workmanship is revealed, with the entire bike spotless, but featuring a minimalist set of colours to highlight an amazing creation.

Eval Motorcycles - Upheval

Solid copper lines for oil and fuel look the business, with gold coloured nuts, bolts and fitments also standing out

Gold nuts and bolts set off the polished rear hub, engine cases, heads, headers and similar, on the backdrop of black bodywork with deep red accents. Scott Skinner did the painting, with Shane Coulthard responsible for the decals, which Billy and he designed, including the prominent racing numbers. Even the engine cases have red inlaid into the deeper sections, with Eval proudly adorning both the cases and the tank.

Eval Motorcycles - Upheval

A stunning Ariel tank that has been modified to suit the project with a very finely detailed tank cap

The tank itself is a modified Ariel unit, while the oil tank is the custom front mount item previously mentioned and particularly visible thanks to the copper lines leading back to it, while spiralled copper lines from the tank to the carburettors are particularly eye-catching. The tail units, situated under the seat are dual tool boxes from a 1949 AJS 500, with the rear mudguard also an AJS unit, modified to suit, but from the same model.

Eval Motorcycles - Upheval

Junk Motor Japan seat, customised to suit the project

The amazing seat may not look the most comfortable but is in keeping with the rest of the bike, and is handmade by Tom from Junk Motor Japan, but has been modified to suit this particular build. You can see JunkMotor inscribed along the centre-line of the seat.

In fact the seat itself was part of the inspiration for this entire project, with Billy purchasing the seat at the Mooneyes the year before this project took place, with the seat actually mounted on a polished damping rod spring which softens the ride, if not the surface of the seat itself!

Eval Motorcycles - Upheval

Aggressive low ‘bars with handmade wooden grips

As you’d expect with such a custom project, the controls, which are aggressively rearward mounted at the rear axle, are all bespoke items made by the Eval team, with Billy and Paul ensuring they are in keeping with the rest of the machine.

On the front end a Mooneyes oil pressure gauge is the only instrumentation you’ll need, with no tachometer or speedometer to distract you, and those drop down ‘bars, like everything else, were all made in-house by Eval Motorcycles. In fact the grips on those ‘bars are, as you may have guessed, timber and are hand made items.

Eval Motorcycles - Upheval

The headlight comes from a ’20s boat and is bracketed by the girder springer front suspension that was custom made by the Eval team

The front headlight is also a (very) oldschool headlight from a ‘20s boat, while the rear stoplight is a taillight from an American car from the same era.

With over 1000 hours spent over seven months on the build, Billy was loathe to even think about the cost and the end results are unquestionable. It’s the type of motorcycle you’ll find something new and impressive on, every time you take another look, with every possible detail covered, with a custom part, designed specifically for that job.

Eval Motorcycles - Upheval

Eval Motorcycles – Upheval

Talking to Billy about the build he admits that while it was a fun project, the strict deadline was something he didn’t particularly relish, “This bike was built in seven months and there were a lot of enjoyable moments, but the pressure to have it finished to be heady to ship to Japan got stressful towards the end.

“That’s also considering almost every part on the bike was made from scratch of highly modified, slowing the production build time, but hell yea would I do it again, I’d just give myself a bit more time.”

Eval Motorcycles - Upheval

Eval Motorcycles – Upheval

When I asked about future plans for this particular machine Billy also admitted there was something he had in mind, “I would like to eventually give it a run on the salt just for fun and see what it can do!”

I also couldn’t help but ask what made Eval Motorcycles so special, as I knew the answer was going to worth hearing, having seen this bike, with Billy saying, “Eval Motorcycles specialise in unique styled custom motorcycles, we prefer to design and manufacture our own parts, rather than use off the shelf parts. We specialise in Harley-Davidsons, early Japanese café racers and Japanese trakkers. It’s all about unique styling, handmade parts, and our passion and attention to detail.”

It’s an amazing creation, and you can tell that Billy and his team at Eval Motorcycles really have the passion for what they do.

Eval Motorcycles - Upheval

Eval Motorcycles – Upheval

Eval Motorcyces – Upheval Specifications

ENGINE: 1986 Harley-Davidson Sportster 883, bored to 1000cc, ceramic coated pistons, Andrews V6 Cams 241 lift duration 264, shot peened connecting rods, ported, polished and flowed head, roller bearings, 10.5:1 compression (9:1 standard), four-speed gearbox (hand shift), H-D clutch, Daytona Daytec ignition, velocity stacks, custom Eval downdraft Webber alloy ,manifold, one-piece Eval Speedway style headers, straight through Eval exhaust, O-ring chain final drive, running AVGas, machining by Powerhouse Engines

CHASSIS & BODYWORK: Customised Paughco mild-steel frame, telescopic (damped) seat post, 50 plus custom CNC brackets and mounts,  custom handmade girder springer front suspension including 1951 Ariel springs, custom unbraked front hub from USA, Paughco 21in rim (f), Sportster 16in rear wheel, 40 steel spokes each, Iron Head Sportster rear drum brake, full custom Eval linkages/controls, modified Ariel fuel tank, modified 1949 AJS 500 toolboxes as underseat side covers, Junk Motor Japan seat – modified, ‘20s boat headlight, ‘20s American car taillight, handmade timber ‘bar grips

SPECIAL THANKS: Paul Makepeace, Nate Walker, Steve Campbell, Peter Brown, Scott Skinner, Shane Coulthard, Joel Barry, Mat Whitmore, Louise Ayres, my sons Tommy, Harry, Austin, Jess Walker, John Pilla, Lightfoot Engineering

RatedR Parts

Eval Motorcyces – Upheval Gallery

Share this:Share on Facebook
Tweet about this on Twitter