How
I Mounted a Tailbox to my Optima Baron
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View of
Optima Baron lowracer with M5 tailbox. Note that headrest is part of
tailbox support system.
The
tailbox comes without mounts and the user must mount it to bike.
These mods include in addition to the mount cutting the bottom of the
tailbox.
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View
of me riding. Headrest supports nape of my neck and is adjustable fore and
aft. It was adjustable up and down, but proved to be
troublesome. After I was comfortable with the position, I secured it
and problem was solved.
There is a gap between
shoulders and beginning of tailbox. Should have mounted it more forward
(some 6 inches) to lessen gap. This is correctable and I may refine.
Can reduce turbulence and get smother transition between body and
tailbox
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Headrest
and bridge assembly are mounted to seat. Tailbox is then mounted to bridge
with rubber connectors, the same type used when mounting a fairing to bike
(see white plastic screws right and left). Aluminum tabs are rigidly
attached to tailbox midway down seat (lower part of photo) and then
screwed into seat. This method produces a very rigid connection with
little movement between tailbox and bike. Pieces of foam are
placed where tailbox comes in contact with bike to insulate (noise
control) resulting in a quiet ride. This was done one squeak at a time.
Visible on right is a Tupperware container (more discussion later). I can
actually get all my supplies and tools plus a light outer jacket. On the
left side the water bottle is mounted. I opted for a container rather than
a door in the tailbox, because I did not want to violate it's structural
integrity.
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| View
of bridge assembly with tailbox removed. The carbon top support was made
by forming 3 layers of 3 inch carbon tape to a waxed surface of the tailbox to get
correct curvature. Front and back of bridge is made from .250 inch balsa
covered with 3 oz. Fiberglass. Mounted to that on right is water bottle
holder, and on left a 5 inch diameter X 12 inch long Tupperware container
with screw-on top. |
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| View
from right showing container, bridge and headrest assembly. The front part
of bridge (part with large holes) connects to seat via furniture screws.
This part is 2 layers of .250 inch balsa covered with 6 oz. Carbon cloth,
and epoxied to the bridge. Was over designed and could be made lighter in
the future. Could support a load many magnitudes higher.
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| Rear
view of bridge and headrest assembly removed from bike. The headrest
can be separated from bridge. Headrest support was formed to the
contour of the seat by building up layers of .022 thick x 1 inch wide
unidirectional carbon . The top where the headrest mounts to the support
started out as .125 aluminum, but I broke it twice, so it is now .250 inch
solid carbon. This part takes a heavy load, especially when hammering hard
from a start position. |
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| View
of same assembly from front. A .250 diameter carbon tube is visible on
top of bridge. This is only a locator ,and has a threaded insert on top, and
fits into a
sleeve mounted to the tailbox. The tube snugly fits into the sleeve, and
all attachment holes line up for easy assembly and disassembly. Also note
the .50 inch diameter aluminum pieces in the part between headrest and
bridge. These were drilled and threaded for the .250 x 20 tpi furniture
bolts which sandwich the complete assembly to the seat. |
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| Partial
view of the bridge assembly with the headrest support removed. Headrest
was made by forming a shape out of beer/soda cooler foam and then covered
with a leather imitator. |
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| Front
view of the same. I am not satisfied with the method of attaching the
Tupperware container to the bridge. I was anxious to complete
system. A better way would be to cut the front and rear of container
off. Then form an identical shape of the container from carbon. Reattach
the front and rear sections, and
fasten the assembly to the underside of the bridge with epoxy, resulting in a lighter
system. Almost visible in the foreground are the
furniture bolts (large, thin, socket head) bought from Home Depot. |
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| To
compensate (somewhat) for the added weight of the tailbox and mount, I
decided to lighten the front end of the bike. Since I live and ride in
relatively flat Florida, I removed the front derailleur and changed out to
a Dura Ace crank. I ride only in the 53 ring and have not (as yet) needed
to go to the 42. I lightened a new bottom bracket shell and welded it to an
aluminum tube with a wall of .125 inch. I then machined the tube to a wall
thickness of .020. I then layered 5 oz. Carbon to a final overall
thickness of .080 (.020 aluminum and .060 carbon). I reduced 1.6 pounds. |
