Tesi 3D Naked Review MCN

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2013 BIMOTA TESI 3D NAKED BIKE
NAKED
THE TESI 3D
GETS UNDRESSED
VOL. 50 ISSUE 30 JULY 30, 2013 P55
BIKE
The Bimota Tesi
3D Naked is
Bimota’s streetfighter version of
the Tesi 3D.
BY ALAN CATHCART
PHOTOGRAPHY BY KEL EDGE
A
dversity is the first path
to truth, said Lord Byron,
and often it can lead to improvement. So if not for the cervical hernia that Bimota’s chief
engineer, Andrea Acquaviva, suffered some years ago in a bicycle
racing crash, the new Tesi 3D
Naked streetfighter version of the
Italian boutique brand’s family of
hub-center models might never
have been built. But after creating the new-generation Tesi 3D,
which Bimota launched in 2008,
thanks to its clip-on handlebars
and sportbike stance, Acquaviva
found it impossible to ride his latest and greatest for more than a
handful of miles without it becoming – literally – a pain in the neck.
“So I did the obvious thing and
bolted on a one-piece handlebar,
and that delivered a much more
upright and more comfortable
riding position,” says Andrea.
“Paradoxically, it also made the
bike considerably more controllable, and agile and, while I’m
not an exceptional rider, I found
myself beating my friends with it
on Sunday morning rides over
the mountain passes inland from
here, like the Passo del Muraglione. So although we’ve built
more than 100 examples of the
Tesi 3D since production began
in 2008, and it’s been very well
received, we decided to launch
a streetfighter version based on
my own bike. I’ve been riding it
for four years, so it ought to be
properly developed.”
The Bimota Tesi followed in the
tire tracks of the Honda-supported ELF GP racers of the previous
decade, in seeking to break the
established mold of two-wheeled
chassis design – but this time
for the street, not (only) for the
racetrack. Around 290 Ducati
desmoquattro-engined
V-twin
Tesi 1D hub-center streetbikes
were built up to 1994, when the
company opted to focus on the
more conventional four-cylinder
models that were its meal ticket
to survival.
Back when I raced the Tesi 1D
for Bimota, Acquaviva was my
factory race engineer, a youthful
apostle of two-wheeled alternative thought who personally built
both my Tesi racebikes. Twenty
years later, now aged 44, he’s the
born-again Bimota company’s
technical boss, having rejoined
them in 2005 after seven years
away. One of his first tasks was to
design a modern reinterpretation
of the Tesi.
“I wanted to make something
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The 3D Naked still uses hubcenter steering, but it sits more
upright than the Tesi 3D.
quite different to the original 1D,
which resolved its drawbacks,”
says Acquaviva. “The most important of these was the very
restricted steering lock, which
made the bike quite impractical
in everyday use. Next was to reposition the front shock to stop
it interfering with your knee, and
also to make the bike narrower,
so it’s more responsive and
easier to steer. I also wanted to
redesign the steering system to
make it more direct, as well as
less bulky.”
Five years after the debut of
the born-again Tesi 3D, the customer Tesi 3D Naked version of
Acquaviva’s revived design appeared at last November’s Milan
Show, powered by the EVO version of Ducati’s air-cooled 1100
desmodue V-twin engine, as fitted to the Hypermotard. And now
it has entered production.
So to create the Tesi 3D Naked, Acquaviva has wrapped the
Ducati desmodue motor in a pair
of vestigial Omega-shaped frame
spars milled from solid billets of
Carpental aluminum, which provide the mounting points for the
front and rear swingarms (the
rear one also pivots in the engine
cases). These spars also carry
(Top left) The hub-center steering
makes the Tesi 3D truly unique.
(Above) The bike is powered by
an air-cooled Ducati desmodue
engine.
(Left) The cockpit of the Tesi 3D
and riser handlebars instead of
clip-ons.
the front tubular steel subframe
locating the steering head, and
its self-supporting carbon fiber
rear counterpart comprising the
seat, which now for the first-time
ever on a Tesi includes space for
a passenger.
To permit this, the previous
3D Sport’s Zard 2-1-2 exhaust
with its twin high-rise underseat
silencers, has been replaced
with a new hand-made Arrow
2-1 stainless steel system with a
single titanium-wrap silencer carried low down on the right. This
has the useful spinoff benefit of
liberating extra power and torque
from the 1078cc Ducati engine,
which now delivers 98 hp at 7750
rpm (three horsepower more
than with the Zard exhaust), and
94Nm of torque at 5250 rpm.
But the dry clutch on the Bimota factory development bike
I was riding was still very stiff in
typical Ducati mode, not yet incorporating the welcome 30
percent reduction in lever effort
delivered by the same engine fitted with an oil-bath clutch as on
the Hypermotard. All customer
Tesi 3D Naked bikes will be fitted
with the wet-clutch motor, says
Acquaviva.
The Tesi 3D’s trademark trellistype rear swingarm with bolted on
aluminum axle plates is matched
to a similar-style twin-sided front
swingarm, with hub-center steering that has a quite different layout than on the original Tesi 1D.
So instead of that bike’s crossmember countershaft (which
took the steering linkage across
the frame from the left to right
side of the bike), the 3D retains
its entire rocker-arm steering
linkage on the left, thus giving a
more direct connection between
the handlebar and front tire - with
fewer right angle turns to dial out
feedback.
It also has a much better steering lock of 23 degrees com-
pared to the 1D’s 17 degrees, of the Tesi 3D, which seems like
which while hardly exceptional is a three-quarter scale version of
still comparable with more nor- the much bulkier original bike.
mal sportbikes. Coupled with It’s narrower, lower and above all
the Accossato variable-section shorter.
The wheelbase is down to
one-piece handlebar attached
via 50mm risers to the steering just 54.7 inches, with the motor
head, this makes the new Tesi mounted further forward to demuch more maneuverable to ride liver a balanced 50/50 percent
in city streets or twisting moun- distribution for the 397 pounds
tain roads, as well as making it dry weight, translating to a deeasier to park.
sirable 60/40 percent front bias
Viewed from either end it’s with a 165-pound rider aboard.
immediately noticeable that the
The bike certainly steers
Tesi 3D Naked is pretty slim, quicker, as a fast run along the
and Acquaviva has managed to switchback Strada Panoramica
narrow the chassis by a whop- running high above the Adriping 1.1 inches from before at the atic Sea south of Rimini, amply
point that your knees tuck in to proved. But the first thing I nothe 4.2-gallon fuel tank’s painted ticed was how much more comcarbon shroud. The footpegs are fortable and relatively more spaalso noticeably farther back to cious the Naked version is than
deliver a sporty but comfortable the much more cramped Tesi 3D
stance.
Sport with its under-seat exhaust
So when you sling a leg over system. The 3D Naked is much
the quite low 30.7-inch high more intuitive to ride – it’s a fastseat, you feel much more a part steering, agile-handling bike that
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The bike started out as a
modified 3D when designer
Andrea Acquaviva suffered an
injury that made it impossible
for him to ride the standard
version because of its
sportbike riding position.
begs to be ridden like the nimble,
take-no-prisoners streetfighter it
is.
There’s much more feedback
from the front suspension than I
ever had on the Tesi 1Ds I used
to race, and this was graphically demonstrated for me when I
came across an unexpected rain
shower just as I exited the autostrada on my way back to the factory. I used to hate racing the Tesi
in the wet, because it was hard
to feel what the front tire was doing at the best of times, with so
much feedback dialed out by the
convoluted steering linkage. But
what would almost certainly have
ended in disaster 20 years ago
was saved by the far better feedback from the front tire on the 3D
Naked when I encountered the
wet pavement. And that’s thanks
to a) Acquaviva’s enhanced steering geometry, with a crucial lower
pivot point for the front swingarm,
b) superior compliance and response from the front Extreme
Tech shock, and c) a good dose
of luck.
That easy handling comes
thanks to the 3D’s lean build, balanced feel, good leverage from
the wide-spread handlebar, and
its sharp steering geometry, with
just 20 degrees of head angle
- matched to 106mm of trail for
good stability. Both of those numbers are extreme by conventional
sportbike standards, and capable of instant adjustment over a
wide range of numbers (17º-23º
and 80-120mm) on the 3D chassis.
Another key factor is that simplified steering system that has
been incorporated on this Tesi
evoluzione, which gives enhanced feedback from the front
tire through a linkage with fewer
changes of direction than previous Tesis. And it also uses newgeneration high-precision rodend bearings, which essentially
eliminate most of the play that
was a definite drawback of the
original 1D.
After the first hour or so aboard
the 3D Naked, I gradually began
to convince myself to start exploring the hub-center design’s
number-one advantage. That’s
the ability to brake very hard, very
late, into a bumpy corner, and to
keep up cornering peed where a
conventional bike would collapse
the front fork under the compression delivered via extreme weight
transfer under heavy braking.
In doing so it’ll not only radically alter the steering geometry,
thus compromising handling and
steering, but also sacrifice front
tire grip because of insufficient
remaining suspension movement
to soak up the road shock delivered by the bumps. All that’s usually a recipe for disaster. But on
the Tesi 3D I ended up frightening myself when discovering the
limits of the Michelin Pilot Power
tires fitted to the bike’s lightweight
OZ forged aluminum wheels.
Admittedly, though, the Tesi
2D’s outstanding braking would
put most conventional front tires
in strife. But the Michelins also
didn’t heat up as quickly as I’d
have liked on a cool summer
morning… but it appears likely
that production versions of the
bike will be fitted with Continental
rubber, which I don’t know well
enough to comment on.
But a major improvement in the
3D’s handling over previous Tesi
variants is Acquaviva’s front suspension format, which employs
a gas shock specially made for
Bimota by Extreme Tech. It’s
mounted on the right side of the
bike, where it contributes to the
3D’s narrow build.
With the suspension compressed up to 80 percent of
travel, the Tesi can apparently be
inclined at a race-worthy 50 percent lean angle without anything
grounding out, or the suspension
freezing, says Acquaviva.
Unlike on the Sport model,
whose dual-chamber gas/air
shock was operated Buell-style
in traction by the front swingarm’s
rocker arm linkage, the Tesi 3D
just a touch of dive to give crossover riders the impression they’re
actually stopping. The way a hubcenter bike stays so flat under
braking is one of the things that
takes most getting used to for
Tesi tyros – but you can dial in
as much dive as you want via the
hub-center equivalent of sag.
On the 3D Naked this was set
just right. I could still feel the front
shock soaking up the road rash
as I slung the bike on its side into
the rippled tarmac of a mountain
curve. I bet dialing this in wasn’t
the work of a moment, especially with the high and low speed
The first thing I noticed was how much
“more
comfortable and relatively more
spacious the Naked version is than the
much more cramped Tesi 3D Sport with
its under-seat exhaust system.
”
Naked version has a more conventional pair of identical cantilever Extreme Tech coil-over
shocks.
“Ducati altered the architecture of their EVO version of the
1100 desmodue engine,” says
Acquaviva. “So we no longer had
the space for the original front
suspension system, hence the
redesign.”
You can feel clearly how well
this new setup works when
braking hard on the lean over a
bumpy surface into a sweeping
turn, with the front shock displaying super-compliance alongside
damping settings on the shocks.
But Acquaviva and his guys
have got it right on this bike, although ride quality on rougher
road surfaces up in the hills
wasn’t the greatest, thanks to the
reduced wheel travel of the cantilever rear end. But suspension
compliance was good – it just
has a relatively small window of
operation.
They’ve also completely resolved the issue of the Tesi tango
that was such an issue with the
first 1D Tesi. A fast blast home
along the autostrada revealed
that even with the more upright
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The Tesi 3D naked
version weighs
in at 390 pounds
dry and has a
wheelbase of 54.7
inches.
riding stance, the new 3D Naked bike ran straight as an arrow
along the at the 142 mph I saw
at 7500 rpm with me wishing I
could get tucked away better
behind the vestigial triangularshaped screen.
Even getting caught in the turbulence of a Mercedes or Volvo
dawdling in the fast lane didn’t
upset the Bimota, though at lower speeds behind trucks it’d get a
brief shake on as my unprotected
body caught the edges of the
windblast.
This Tesi 3D done differently
is a very good motorcycle by any
standard, but especially once the
rider reboots and remaps his/
her mental computer to get the
best out of a hub-center motorcycle. So, hold the bars lightly,
and don’t be afraid to stay off the
brakes until what seems suicidally late. Then, when you do decide to stop, don’t be concerned
about grabbing a big handful of
front brake and squeezing the lever hard back as you lean into the
apex of the turn, while still scrubbing off speed.
The separation of steering from
suspension functions on a bike
like this is the biggest asset of
hub-center front ends - only that
you must first convince yourself
that you can trail-brake so deep
into turns, then do it.
But the assured suspension,
confident steering and good
balance of the Tesi 3D Naked
package means that it’s a bike
that likes you to keep up cornering speed – it’s not a stop/turn/
gas-it-wide-open package like
the original 1D was. This means
you can use a gear higher in
many turns than you might have
expected – a feature which the
extra grunt of that great Ducati
desmodue EVO engine will happily go along with.
This version of the air-cooled
desmo V-twin motor has a much
smoother pickup from a closed
throttle, as well as a less aggressive power delivery that’s more
refined-seeming than its predecessors. But it’s still a meaty motor and ideally suited to the Tesi
application. Magic.
A delve into Bimota’s back
catalog of past products has delivered a future bike that functions
and is fun to ride, two decades
on from its customer inception.
Who says you can’t re-invent the
wheel – even if it has to be a hubCN
center one?