I really haven't read much at all about this bike. What's the reason Eric decided to use a different engine? It was just a few years ago he was so passionate about keeping the much simpler, more than efficient air cooled lump.
Probably because the "air cooled lump" generated too many compromises in the execution of a modern sport bike... the press rated the handling "quirky"...
Quote Sportrider:
"Ask any motorcyclist about the Buell XB12R Firebolt, and you will
invariably get either an extremely positive or extremely negative
reaction. Our testers are no different and, in general, are similarly
divided in their subjective opinions of the bike. In our last test of the
04 Firebolt ("Fighting Fire with Fire; Dec. 03), as with the original
XB9R, we were stymied by what we called "quirky handling" and
frustrated by how easy it was to go astray with the bike's setup. We
experimented with our 04 test unit and then an '06 version, with the
goal of making the Firebolt less sensitive to chassis setup, as well as
removing some of the quirks."
"While many riders praise the Firebolt's cornering abilities, stability
and suspension, others are disconcerted by its steering
characteristics. Those properties include a desire to stand up on the
brakes, generally heavy steering and the requirement for constant
force on the inside clip-on to hold a steady line. Experienced riders
can tweak the suspension to minimize the distractions those handling
traits present or simply deal with them more easily than others. But
we are curious types and wanted to improve the Buell's steering
without sacrificing any of its positive traits."
IN THEORY...
When a motorcycle leans to turn a corner, there are many forces at
work. These are determined by more than just the steering geometry.
Tire profile plays a big part, especially at moderate lean angles,
thanks to a property generally known as camber thrust. The effect of
camber thrust can be shown by picturing the front wheel as the
base of a cone turned on its side, with the side of the cone rolling
along the pavement.
Leaned into a turn, the tip of the cone would be an imaginary point
on the pavement inside the turn, its position determined by the tire's
profile. Just as the imaginary cone will turn to one side if rolled, the
front wheel will try to turn into the corner and not go straight. If
other cornering forces do not perfectly offset that turning force, an
additional rider input will be required to keep the bike holding a
specific turning radius.
"Many factors contribute to how this camber thrust is offset, but the
Buell has a constant requirement for the rider to counter steer into
the turn. In our experience, this effect is sometimes a result of a
too-steep rake angle (the Buell has a rake of 21 degrees), and
traditionally we have always raised the front ride height of our Buell
test bikes to offset this. This increases trail as well, however, making
for heavier and slower steering. This is where the knife-edge of the
Firebolt's setup comes into play: As the camber-thrust effect is
gradually reduced by adding rake, the additional trail makes steering
too heavy before the camber thrust is eliminated. There is no
happy medium."
IN REALITY...
"Another factor that makes the Firebolt's steering feel awkward to us
is the clip-on placement. The bars are mounted to the top triple
clamp and are located far ahead of the usual position, just in front of
the fork tubes. The swing effect introduced by this location-the bars
move sideways considerably when the front end is turned-leads to
a lot of wasted effort when steering. Our first modification to the XB
was to replace the top clamp with a Heli Performance unit ($320),
which brought the bars closer to the fork tubes and slightly higher.
While rake and trail can be adjusted independently using aftermarket
triple clamps, we went right to the source and tried different tire
combinations and profiles, including rounded and triangular extremes
and even a 60-series front tire. For each setup, we adjusted the
suspension and front ride height to find the best compromise, and our
final iteration of the '04 project Firebolt used Michelin Power Race
tires. The low profile of the front Power Race bun let us add rake (by
raising the front of the bike) without adding excessive trail, and we
were able to find a good setting that minimized the bike's camber
thrust and kept steering reasonably light."
"Now there was a range of ride heights albeit a small range-in which
the bike had almost neutral steering. During a track day at the
Streets of Willow, one rider who tests lot of American iron proclaimed
it the best Buell he had ever ridden. At that point, we had to return
our Firebolt, but we gladly took possession of '06 model in return. We
swapped over all our goodies from the old bike to the new, along with
some additional upgrades. Buell's Pro-Series suspension kit, which
consists of a set of slightly stiffer fork springs and a straight-rate
shock spring (the stock unit is progressive) was installed, and using
what we learned from the '04 bike and our giant street tire test
("Street Sense"' Dec.'05), we spooned on a set of Michelin Pilot
Power tires."
"Right away, we could tell the combination of the front Michelin's
profile and the Pro-Series springs was almost perfectly suited to the
Buell, with the steering light and neutral at practically any lean angle.
Only at higher speeds can the new project bike's steering be
considered heavy, and even in that case, it's lighter than stock.
We've always praised the XB's quality Showa suspension, and the kit
parts improved it even further. The rear spring especially allows full
use of the shock's travel, providing a plusher ride and allowing the
bike to track much better over rough pavement."
WHAT ABOUT THE REST?
"We mounted up a set of Sato Racing's rearsets ($650), which have
short, solid-mount footpegs on adjustable brackets. Installation was
a snap, although the brake pedal needed a small spacer that wasn't
in the kit. To accommodate the drastic ride height changes we were
making, we swapped out the stock stainless steel front brake hose
for a slightly longer part we happened to have in the shop."
"In the engine bay,we started with a Buell Pro-Series race exhaust
($359.95), ECM ($209.95) and air filter ($64.95), but switched the
very loud Buell pipe for a beautiful Ti Force 2-into-l-into-2-into-l
stainless steel system ($1320.90 from Orient Express). The Ti Force
pipe doesn't make quite the top-end power of the Buell race pipe, but
it really bumps up low-end and midrange over the stocker. Both
setups ran better with the Pro-Series ECM installed, as opposed to
the stock blackbox. Interestingly, the '06 bike's new air intake-a small
grille behind the fuel filler cap-looks small, and we picked up a couple
of free horsepower without the faux gas tank cover installed."
"Overall,the project 'Bolt is a lot of fun to ride and flat-out hauls butt
on tight, twisty roads that would have a stocker struggling. It's
steering now allows the XB rider to concentrate more on riding and
less on the distractions the stock bike presented, and the bike is
much less-tiring to ride, as well. It's been one of the more extended
projects the Sport Rider crew has undertaken, but now we're hoping
to hang onto the bike even longer."
Heli Modified
800 859 4642
www.helibars.comMichelin
800 847 3435
www.michelin-us.comOrient Express Powersports
(516)546-5232
www.tiforce.comSatoRacing
(714)779-8325
www.satoracing.com
