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Dahon and Rolf Develop the World's Lightest
Wheelset
Wheels will be used exclusively on Dahon's
folding bicycles.
DUARTE, California — November 21, 2002—
Dahon California, Inc., the world's leading manufacturer of
folding bicycles, today introduced the Rolf® Prima Accel
wheelset, a high performance wheelset that is the lightest,
and very possibly the fastest, in the world. The wheels use
Rolf's patented Paired Spoke Technology™ to produce incredibly
strong, low-spoke count, and aerodynamic wheels. At only 995
grams the Rolf® Prima Accel wheelset is the lightest production
wheelset in the world. The Rolf® Prima Accel wheelset will
be used exclusively on Dahon's folding bicycles.
"We began this project with the goal of developing the
lightest and fastest 20" wheels ever produced," stated
Joshua Hon, Dahon vice president of sales and marketing. "But
we outdid ourselves - we ended up with the lightest production
wheelset ever, including even the best 700c racing wheels. And
while our wheels haven't been in a wind tunnel yet, Rolf's 700c
wheels have been tested and confirmed as among the most aerodynamic
(i.e. fastest) wheels on the market. We're betting that the
smaller profile of our wheels will prove our new Rolf® Prima
Accel's to be the most aerodynamic wheels in existence."
"Small wheels are by definition, faster to accelerate,
stronger, and more aerodynamically efficient than comparable
larger wheels," stated Rolf Dietrich. "But even I
am surprised and impressed with the end product. Tackling the
challenge of this project with Dahon has been a lot of fun and
I look forward to future projects together."
The Rolf® Prima Accel wheelset includes several patented
technologies that add up to lighter, stronger, and faster wheels.
Every component of the wheel is optimized for speed, strength
and durability. Front Hub: The Dahon custom-designed
front hub features a forged one piece hub shell and is one of
the lightest hubs in existence at 54 grams. The patented design
places the cartridge bearings as close as possible to the point
of loading at the fork ends for improved strength and durability.
Flanges are a beefy 4mm in thickness, to take the stresses of
high spoke tensions.
Rear Hub: An engineering masterpiece. The rear hub weighs
only 213 grams and features a patented six pawl cassette design
that engages all six pawls simultaneously when drive torque
is applied. No other cassette design engages all pawls simultaneously.
The six pawl cassette design is significantly stronger and more
durable than traditional designs. The pawls are also placed
as far as possible from the center of the hub to maximize leverage
and to ensure disengagement for smoother coasting. The asymmetric
flange diameters produce more uniform spoke tension and effectively
double the number of "pulling" spokes. The rear hub
also features a unique narrow flange spacing to optimize strength.
The drive side flange is placed as close to the cassette as
possible while the non-drive side flange is spaced closer to
the center, which results in more evenly balanced spoke tension.
The non-drive side spokes share a larger percentage of the total
load, resulting in stronger and more durable wheels.
Rims: The rims feature a deep aero profile and are manufactured
using aerospace grade aluminum. The rims feature Rolf® Prima's
Paired Spoke Technology™ drilling and a spoke count of
14 for the front wheel and 16 for the rear. The low spoke counts
and aero rim profile deliver excellent aerodynamic characteristics.
Even the spokes holes on the rims are patented. The spoke holes
feature a chamfered shape that allows the spokes to align themselves
perfectly, eliminating any bending moment that is the most common
cause of spoke failure.
Spokes: The ultra-light, double butted spokes are manufactured
to Dahon specifications by the supplier to the world's top racers.
The spokes are cold forged in a proprietary process out of the
highest quality stainless steel.
Nipples: Rolf® Prima's custom spoke nipples are recessed
within the rim to further enhance aerodynamic performance. The
patented special shape of the spoke nipples, combined with the
proprietary spoke holes, allows perfect spoke alignment. Each
nipple features an internal Nylok coating to eliminate any loosening
after wheel assembly.
Assembly: The build process for each Rolf® Prima
wheel is time-consuming and requires painstaking attention to
detail. Due to the low spoke count, spokes are adjusted to more
than double the tension of spokes in traditional wheels. The
process begins with each wheel meticulously laced and trued
by a wheel building expert. Then the wheel is mounted in a special
machine and de-tensioned. Then the wheel is trued again. Again
it is set into the machine and de-tensioned. The wheel then
goes through one final truing process by our master wheel builder.
The Advantages of Small Wheels: Smaller wheels have a
number of distinct advantages when compared with traditional
700c wheels. Smaller wheels have a lower moment of inertia so
accelerate much more quickly than larger wheels. The reduced
profile of a smaller wheel means lower aerodynamic drag. A smaller
wheel is also by definition stronger and stiffer than a larger
wheel with comparable components. A little known additional
benefit of smaller wheels is that they allow a rider to tuck
in closer when drafting behind another rider, for greater aerodynamic
benefit. It may surprise some to learn that the world cycling
record for speed (unpaced, traditional riding position) of 51.29
MPH was set in 1986 on a small wheeled Moulton bicycle.
"The idea to develop these wheels started because our bikes
are increasingly being used in performance applications,"
stated Hon. "For example, our Speed Pro bike is the official
training bike of the German national speed skating team. You
can imagine that these speed skaters really push our bikes to
the limits. These types of riders demand the very highest level
of performance from their bikes and components."
The Rolf® Prima Accel wheelset will be found on 2003 Dahon
Helios XX and Speed Pro models. The wheels will also be available
as an after-market upgrade. The wheels will retail for US $500.
Rolf® Prima Paired Spoke Technology™ is used by many
of the top road racers in the world, including present and former
Tour de France and world champions.
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