There’s a protracted historical past of purpose-built cars that use bike engines. Mix a robust sufficient motor with a light-weight sufficient chassis, and the outcomes may be very passable. However what about sticking a automotive engine in a motorcycle? That’s a completely totally different ballgame.
Followers of classic German engineering ought to acknowledge the ability plant on the coronary heart of this hand-built chopper. It’s powered by the air-cooled four-cylinder boxer from a VW Beetle—and, as you’d think about, it took a bit of little bit of ingenuity to place collectively.
It’s the work of Paul Clark—an English hobbyist that builds {custom} bikes for the love of it, fairly than for business acquire. A fan of older and rarer marques, he’s constructed up fairly a group of machines (and spare elements) through the years.
“I’ve constructed a Dnepr chop, and a J.A.P. rotavator-engined bike, in addition to others,” he tells us. “These bikes aren’t shiny—removed from it—and they aren’t one thing the place somebody will pull alongside and say ‘I’ve obtained a type of.’ They’re distinctive to me, my type, and I like them—but it surely’s additionally good when different folks admire them too.”
Paul additionally likes to maintain his initiatives low-cost, by utilizing as many up-cycled and scratch-built elements as potential. This one kicked off with an eBay discover; a £300 [about $379] VW Beetle engine begging for a house. “Utilizing the engine as a base, sat on my workshop ground, I began to visualise the completed bike in my head,” he says.
The primary problem was to connect a transmission to the motor. Paul mated a Dnepr MT 650 gearbox to the VW mill, by way of concentric flanges that have been waterjet-cut from aluminum. A Dnepr clutch and flywheel have been tailored to work, too, together with the alternator from a Kubota mini digger.
Wassel Evolution carbs inhale by means of an Amal velocity stack, hooked up by way of a {custom} manifold. The snaking pipes on both aspect of the engine appear messy at a look, however if you happen to hint them rigorously you’ll be capable to make out the road of Paul’s bespoke stainless-steel, four-into-two exhaust system.
“As soon as they have been fitted, they have been dangerously near the rider’s legs,” he provides. “I didn’t need exhaust wrap or warmth shields, so I opted to purchase some knee excessive boots to put on when using; the issues we do to maintain the aesthetics as we would like them!”
With the fundamentals out of the way in which, Paul arrange a makeshift wheel alignment jig utilizing a metal beam. 16” rims have been laced to a Dnepr entrance hub and a Honda Goldwing rear hub, shod with recent rubber, and set within the jig, together with the engine and gearbox.
Beginning with a partial 1983 Honda Goldwing body, Paul mocked up the chassis with bits of spare tubing and broom handles (sure, broom handles). The ultimate body was welded up out of metal tubing, once more procured from eBay, with the triples and forks from a Yamaha XJR1300 up entrance. The body’s 50 mm stainless-steel prime tube additionally acts as an air reservoir, for a TC Bros ‘Air Experience’ system that sits below the slim chopper seat.
“I feel that the seat all the time appears higher as near the tire as potential,” says Paul, “particularly as there is no such thing as a rear mudguard. It occurred to me early on that it will be nice to have a seat that goes up and down—however I didn’t need springs, so I opted for an air bag. It appears nice when the bike is parked up, and is actually comfy when using.”
A small 12 V air compressor ‘fees’ the highest body rail to round 40 PSI, which is sufficient for the seat to go up and down about 4 instances. Look intently, and also you’ll spot a small air stress gauge mounted simply in entrance of the seat.
If the gasoline tank appears acquainted, it’s as a result of it got here off a Triumph Bonneville. Paul cut-and-shut it to sit down wider, and tailored it to suit his body. Simply in entrance of it are custom-made handlebars, with Massive Port Beston-style grips, a throttle, the brake and clutch levers, and little else.
Paul doesn’t like new and glossy bikes, so the body was shot blasted and zinc plated, then wiped over with a firearm coating and range polish. That gave it an aged solid look that may match the engine. First Selection Physique Store dealt with the pink paint job, Central Wheel Elements did Paul’s powder-coating, and Brimscombe Platers tackled all of the sharpening and plating jobs.
As a ultimate contact, Whiteway Craft Foundry constructed a small battery field that doubles up as an alternator mount. The truth that it appears a bit of like an outdated VW bus isn’t any accident.
With the undertaking nearing the end line, Paul contemplated if his 132-pound body would be capable to kickstart (sure, he opted for a kickstarter) the chunky VW boxer. “Sure, it began—what a reduction” he quips. “It’s really fairly straightforward to kick over.”
Nearly prepared for his first shakedown run, Paul then hit the most important snag of the undertaking. “I’m a little bit of a hermit when constructing,” he explains, “however recommendation about unusual technical particulars is all the time readily available from my oldest buddy, Neil Baxter. He came visiting for a cup of tea one night and casually stated, ‘are you positive the rear wheel isn’t going to run backwards with the shaft on that aspect of the wheel?’”
“The propshaft was intently becoming with no room to vary something. We tried it, and, shock and horror, the wheel was working backwards! I used to be so dejected at this that I almost scrapped the entire undertaking—however with some encouraging phrases, it was a case of checking out this unexpected drawback.”
Ultimately, Paul needed to scrap the Goldwing rear wheel and bevel field, and substitute them with a repurposed Dnepr ultimate drive and hub. With a {custom} metal cowl on the ultimate drive, the entire association solely simply match into the body—however the vital factor is that it did match. Two weeks later, the VW bike was prepared for its shakedown.
“I obtained 20 ft, and it died,” says Paul. “A burnt-out coil gave the impression to be the issue. Two additional coils later, it turned out that that the Lithium battery wouldn’t behave with the alternator, and changing it with a small gel battery sorted the issue.”
Lastly on the street, Paul’s joyful to report that the bike pulls robust, topping out at round 60 mph. However because the Dnepr transmission has a 4 gears and one reverse gear, he may modify it so as to add a fifth gear.
“It’s not humorous while you’ve spent numerous hours constructing a motorcycle, solely to search out that it has one ahead gear and 4 reverse gears. Having to chop up a freshly constructed, laced and painted wheel is annoying within the excessive. That specific drawback almost did it for me—however I’m so glad it obtained sorted and the bike obtained completed.”
“The bike has its personal brand, which is a reverse VW; the W on prime with the V beneath, as a reminder to examine such issues a lot earlier within the construct subsequent time. It additionally goes by the title of ‘Bootsy,’ a reminder to place my new very excessive boots on except I wish to set fireplace to my trousers.”
Pictures by, and with because of, Del Hickey
