When your last project involved shoehorning an Alfa Romeo car
engine into an aftermarket Harley frame, what do you do for your
next one? Well, if your name’s Chris Barber and you’re
responsible Crossbreed Cycles, you come up with an even more twisted
idea – mating a Harley bottom end with a Ducati top end.
The spark for the idea came when Horst Heiler, a German motorcycle
magazine editor who’d previously written a feature on the
Alfa, sent Chris a picture of his own bike, which featured a Shovelhead
cylinder head mated to an NSU motor.
Of course, Chris couldn’t
simply copy this idea wholesale. Firstly, it had already been done
and NSU motors are not exactly commonplace in the States where
Chris was living at the time. Then again, Harley engine parts are
as common as muck over there and cheap as you like on eBay, which
is where Chris duly picked up a set of Evo crankcases.
Now, to build a hybrid motor around and onto said cases, Chris
needed a top end, but from where? Well, having spent his youth
riding, destroying and then rebuilding Fizzies before discovering
cars and girls, when he returned to bikes, it was to the Ducati
marque that he was drawn. The first one he owned was a 900SS, and
fortunately he still had a set of heads knocking around in his
garage somewhere. Problem solved. Hah! If it was that easy we’d
all be building bastard love child engines, wouldn’t we?
The reason that Chris had been living in America was that he’s
involved in the semi conductor industry. No, I don’t know
what they’re used for either but apparently there’s
a lot of money involved and mobile phone technology relies on them.
Chris’ job out in the promised land was running the workshop
that kept the machines in the semi conductor factory working smoothly
to produce a steady flow of the things.
Being an enterprising sort of chap, Chris convinced his employers
that his workshop really needed filling with state-of-the-art CNC
machines, and that it would also be a very good idea to provide
him with the very latest software package in order to operate all
of this equipment. Not for one minute did it enter his head that
it might also prove to be extremely useful when it came to his
personal bike-building projects. Well, that’s what he told
me, and who am I to disagree…?
It was strange then, that he would often find himself with the
odd period of downtime in the workshop when the software wasn’t
being used for anything and the CNC machines were idle. There was
only one thing for it then, which was to put it all to work designing
the one-off components required to marry his Italian cylinder heads
to the American set of crankcases.
The first step was a set of barrels that would bolt to the Evo
cases while, at the same time, allowing the heads to be bolted
down. The resulting CAD drawing was then shipped off to Axtell,
a company that specialises in that sort of thing. Now, just to
prove that Chris might be talented but not infallible, he admits
to making a mistake with the drawings and the barrels ended up
an eighth of an inch too tall. Fortunate, then, that he found a
set of over-length Carillo conrods on eBay going cheap… because
they were too long for a regular motor. Job’s a good ‘un.
The next task was designing and machining up the blocks to hold
the gears that take the toothed drive from the Harley’s camshaft
and convert it to belt drive to suit the Ducati heads. Luckily,
it was a quiet week in the office when Chris took that one on…
If I was clever enough to get that all figured out satisfactorily,
I’d have been happy to call it a day and move on to finishing
the bike but Chris isn’t just an engineer, he’s also
an artisan. To him, something just didn’t look right. Well,
that was until he got a second 900SS rear head and mounted it on
the front pot after turning it through 180 degrees. Apparently,
it works better visually as the cooling fins line up and it angles
the Mikuni flatside carbs evenly on each side of the bike.
to prove that not everything on Desmohog, however, was high tech
computer designed and machined – the carbon fiber velocity
stacks the carbs are wearing were moulded on Pot Noodle pots and
finished off with discs cut from kitchen sieves!
Given the work he’d put into the motor, you’d think
it would be a simple job for Chris to match it to any gearbox that
took his fancy. Well, it would have been, but when eBay threw up
a cheap RevTech 4-speed Shovelhead-style ‘box stuffed with
five gears and a kickstart, it would have been rude not to have
bagged it, so he did. It also made it easy to bolt on a BDL primary
belt drive set-up.
At this point in the build, things had to slow down due to an
impending move back to the UK. However, before leaving the States,
popped over to Kustomwerks and scored one of the Kraftech rigid
frames which it distributes and packed it up along with his belongings
ready for the journey home. Shipping it amongst his furniture also
helped to avoid getting hammered by HM Customs and Excise when
he arrived back in Blighty.
One last piece Chris collected before he left the USA was the
aluminium petrol tank. Another eBay find, its exact origins remain
but he but he thinks that it’s an aftermarket tank from the ‘60s
intended to fit a Brit bike.
Once Chris was reunited with his various boxes of bits down on
the south coast, he started to throw it all together to get the
Desmohog up and running as quickly as possible. Well, you’d
waste no time either if you’d just done a deal for a Maserati
car engine as the basis of your next project.
A few hours browsing the internet soon yielded a front end from
an anonymous Jap dirt bike and a set of 17in Excell rims laced
onto XL650 hubs that’d originally been destined for a supermoto
project. Chris didn’t buy the wheels just because the price
was right – he actually wanted them in that size. As he says, “Bobbers
might look cool with 21in wheels but they’re a bugger to
ride. So I’ve put sensible sized wheels on mine.”
The choice of 17-inch rims also opened up a whole range of available
sports bike tyres to Chris, which fits in with his idea of building
what he describes as a café bobber; a mix of traditional
American Bobber and classic Brit café racer. All of which
explains the styling of the seat hump. While he may have been keen
to get the bike finished and on the road, he still took the time
to create a virtual 3D model of the seat hump in CAD and then virtually
slice it into 12mm-thick sections. He then transferred the dimensions
form those slices to sections of MDF and glued them all together
to create a buck from which he could take a mould. This was then
covered with layers carbon fiber to create the seat hump.
The subframe that Chris constructed to hold said seat hump incorporates
a stainless steel oil tank with integral filter, which he TIG-welded
together when he was finishing off the Desmohog. And while he had
the TIG gear out, he also knocked up his own rearsets and a top
mount for the engine.
Now that the Desmohog is up and running, Chris is unsure what
he ought to do with it; keep it as a run about, or sell it and
on with his Maserti project. If he does hang on to it, there’s
a chance that the Desmohog finds itself running a supercharger,
to which it would be eminently suited thanks to its relatively
low 9:1 compression ratio, though a slightly thicker base gasket
would drop the ratio by just enough…
Then again, if someone wants to drop him a line at firstname.lastname@example.org,
any reasonable offer would certainly be considered.
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