|
|
After having contacted several manufacturers, it became necessary
to construct a prototype.
For this prototype we moved the secondary suspension arm's pivot
(the one that connects this part to the main frame) lower so the
pivot, the bottom bracket and the rear wheel's axle are aligned.
This was a necessary upgrade from the original design after the
suggestion from Raleigh's R & D Dept. that this system will
biopace all the time! (We don't agree. Turner's Maverick that has
a similar 45-degree link at the bottom bracket, without creating
any biopacing effects). So, Raleigh is wrong (the prototype proves
this).
The prototype has demonstrated exactly what the patent theory claims:
A) The rear suspension's travel is 18 to
20cm and operates bob-free in all situations.
B) The full-floating shock delivers extremely smooth
action with an increasing rate of compression.
C) This system offers increased traction of the rear
wheel, without bobing or stiffening the rear end to the point
of loosing the advantage of the suspension system (despite the
high pivot of the suspension arm).
D) It offers a very stable landing.
E) Depending on the riding position (standing or seated)
|
|
The suspension stiffens, without getting locked.
F) The suspension stiffens according to acceleration
effort, thus saving energy.
G) Moving backwards & forwards on the bike affects
the fork's caster, making the bike more stable at high speeds
of descent and more easy to maneuver in steep climbs (actually
the rear end pushes the frame upwards and forward).
H) The bottom bracket can be placed lower than normally
as it subtracts slightly when the suspension is compressed.
|
Considering that this is our first prototype (not a pre-production
model) and despite the increased weight (18 kilos) we could develop
a trail bike with 145 / 150 mm front travel, 200 rear travel within
the range of 12 to 13 kilos! The bike is equipped with the following:
A) Carbon fibre / kevlar frame & suspension
arm, with fortal alluminum CNC parts. Ertalon bushings (easy
to access for service).
B) Manitou X-VERT DC dual crown fork, 120mm travel.
C) Fox float R (no locking) 165mm eye-to-eye.
D) Shimano XT crankset, aftermarket inner ring, 20-32-44
T.
E) Time attack alluminum pedals.
F) Shram 9.0. SL 11-32 cassette.
G) Shram 9.0. shifters.
|
|
H) Ultegra 68mm, 115 bottom bracket.
I) Shimano XTR front & rear derailleurs.
J) Shimano XT disc brakes.
K) Sacs chain.
L) American classic disc hubs.
M) Mavic 317 disc brake rims.
N) Ritchey logic ahead set.
O) Titec stem.
P) CM riser handlebar
A. Roox 30,8 430mm seatpost.
B. Selle italia transalp ti saddle.
C. Michelin wildgripper XL tires.
|
Despite its increased weight, this bike is able to climb steep ascents
with ease. It turns steadily at high speeds and it is very predictable.
At low speeds, despite its phenomenal high bottom bracket, it can
clear obstacles in technical sections very easily. Have in mind
that the frame geometry appears steeper, with a high bottom bracket
when unloaded. With the proper sag (front & rear) the bike is
in proper geometry.
|
|
|
