Click links below to view the Trimble bikes in our collection:
1988 Carbon Cross
1990
Trimble Aero road bike
1991 Inverse 4
Mid 1980's
Brent
Trimble designs the Kestrel 4000 road bike:
1988
The prototype of the
Carbon Cross frame was shown in the Spring of 1988. This frame was similar
to the later bikes except it was lacking the extra bracing to stiffen the bottom
bracket. According to reviews at the time, Trimble made a prototype out of
solid Douglas Fir wrapped in fiberglass. The first frames were constructed
from a 30% carbon fiber, 70% fiberglass composite. A second article states that
the first bikes were made from E-glass, a fiberglass designed for electrical
applications. The thinnest parts used 6 plies and the as many as 24 layers
for the higher stressed areas of the frame. The frame is a similar style to the
cross frames from the 1880's. This made the bike a little too flexy
and made front derailleur mounting problematic. The frame price is listed
at $1,200 and sold by Trimble Products Company in Berryville Arkansas.
The article above is from
February 1988 and features a "cross frame" Trimble.
The benefits of the frame included low stand over height, being
able to remove the chain w/o tools, some suspension effect from the rear stays,
won't corrode, lack of chain stay slap.Problems included offset crank to clear the frame (bad chain
line), custom front derailleur, one size fits all, tall head tube, difficult
rear brake mounting, flexible bottom bracket leading to imprecise shifting
The article above is another of the Trimble brothers (James) who experimented with road bike designs.
Also shown were carbon fiber Roobar that was designed by Brent's
younger brother "Roo".
The bar is a one piece carbon bar with a
short steel insert in the lower (inserted) section of the stem. Cost was
listed at $125. Roo Bar article can be seen above.The design was worked on during the year and changed to the
Inverted 4 design.
August 1988 Bicycle Guide magazine
article:
1989
The new Inverse 4
frames start showing up with the reinforced bottom bracket area and more
conventional from derailleur mounting. There were rumored to be
approximately 500 of the Inverse 4 frames sold including a few team
issue bikes with a fade paint job and tiger stripes.
April 1989 Bicycle Guide
article profiling the new Inverse 4 design:
1991
Several variations may
have been experimented with including "seat less" frames for trials use or
possible fitment of the Allsop suspension beam. May have begin
experimenting with external cable routing.
1992
April 1992 Bicycle Guide
bike review of the 140 Unlimited model:
The rear dropout is
changed from the 3 hole design to a single hole elevated design. This
raised drop out design accommodated the new longer suspension forks and still
allowed for use of the existing frame mold. The new design also featured a
new front derailleur pulley mounted to the bottom bracket, external cable
routing and a cantilever brake mounting adaptor. There were three models,
the 140, 160 and 180 and each was available in a regular model or Unlimited
model. The number referred to the maximum rider weight while the Unlimited
model had specially machined aluminum pieces to save weight over the regular
frames. The frame price was still listed at $1,200 for the regular models
and an additional $400 for the Unlimited frame. The old Trimble frames
were listed at 5 pounds while the new Unlimited 140 model was two pounds and
nine ounces. Unfortunately, the weight recommendations were often ignored
which gave the bikes a reputation for breaking.
1993
A full suspension bike
was shown by Roo Trimble and Mike Augspurger (founding member of Merlin) that
consisted of the front half of a Inverse 4 bike mated to a rear swing arm and
"Gizbag" shock. The Gizbag consisted of a folded up inner tube sewn into a heavy
duty bag made of nylon webbing. Don't know if it ever got further than the
prototype stage but it sure looked interesting .
June 1993 Bicycle Guide
magazine review of the Gizbag suspension frame based on a Trimble frame
and designed by One-Off:
1998
On the 10th anniversary of the original design,
Dean Ultimate Bicycles licensed the design,
borrowed the mold and planned to make 1500
frames. Estimates range from 15 to 80
frames that were ultimately produced by Dean.
2004
Brent is currently
working on a third generation hard tail design as well as a rear suspension
design. I'll post more details as they become available. Should be
exciting!!
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