|
|
|
|
Assembly begins...
With the front end, engine mounting/bracing &
guard, footrest assembly and sidestand all sorted out, one
might get the impression that it would be a simple matter of
adding decals, wiring and bolting it all together.
Normally, that would be the case. However, nothing about this
build is simple bolt-in, off-the-shelf. This is where all of
the final details get worked-out.
|
|
      |
|
Here are the new wiring harness, LH rear sidecover,
swingarm and engine in as-received condition. The wiring is
from another, current production, bike and needed to be
unwrapped for some fairly extensive modifications to fit at
CT70 and to work properly with the early CT70 style seven-wire
ignition switch. The rear sidecover required substantial
machining/trimming for chain & sprocket clearance with the
large diameter, offset, countershaft sprocket we're using. It
also needed to be polished to compliment the chromed mag and
clutch covers we'll be running. The swingarm is an aftermarket
that we imported from Japan. It's beautifully made, provides a
bit more width between the axle mounts and is lighter than the
OEM swingarm. For this project, however, even the beautiful
TIG welding from the factory just wasn't good enough to use
as-is and there was no provision for a LH buddy peg. You can
hardly blame the manufacturer for those two deficiencies. This
is a racing part and racers don't carry passengers, nor are
they overly concerned about mirror-polishing. Our philosophy
is to take the best available and simply modify it as
needed.
|
|
        |
|
We began by converting the engine wiring back to an OEM
modular plug. Since these engines are almost always adapted to
older bikes, these get removed before the engines ship. A
7-wire CT70H ignition switch was adapted to the 4-wire
configuration of the new harness. Since the new wire harness
already had provisions for the turn signals, headlight
dimmer, horn, gear position indicator lights, fuel gauge, CDI
and new 12V electronic regulator/rectifier it was a
"no-brainer". The gear position indicator and fuel gauge
functions were simply not used. There were a few "surprises",
such as reversed polarity for the neutral indicator light, but
these were sorted-out and catalogued for future
reference. Having full headlight and turn signal control
on the handlebar is a vast improvement over the old keyswitch
arrangement. Riding a bike sans turn signals gets to be
a pain after a while, especially on rough pavement, but turn
signals can be a pain in and of themselves...and they usually
don't compliment the aesthetics of the bike. The solution was
an integrated tail light/signal assembly. We will also be
fitting the fork with LED rings for the front signals. Bear in
mind, pre `73 bikes are not required to have turn
signals in this state.
The sidecover was metalfinished and polished; the
inside was milled for chain/sprocket clearance. The cam cover
was similarly smoothed and polished, along with the exposed
upper section of the engine center cases. This will really
come together once the chrome side covers are
installed.
We machined a mounting boss for the LH buddy peg, along
with the swingarm. Our buds at Majestik welding handled the
TIG welding, turning out even better quality work than the
Japanese factory that manufactured the swingarm in the first
place. We then fabbed a pair of simple mounts from T6 6061, a
billet recreation of the OE style mounts. The polished
stainless, Allen-head mounting through-bolts were
countersunk and the mounts themselves polished. Lastly, the
swingarm was polished to a mirror finish. The photos don't do
it justice.
|
|
            |
| This is where things get interesting...when final
assembly begins in earnest. There is, of course, the
excitement of seeing months of carefully planned work come
together. That gets tempered by the reality of last-minute
adjustments brought about when that mean old "Mr. Reality"
rudely interrupts your smooth-running project. One of
those moments came about when the rear brake stay came back
from chrome looking subpar. We usually do our own
metalfinishing and the plater assumed that was the case this
time, too. With no time left to inject yet another month into
the build schedule, we decided to make a brake stay from
billet aluminum; the final result, with a mirror-polish,
turned out so well that we tossed the chrome-plated OEM part
into the spares bin. The polished aluminum and plated items
added up to a surprising total number over the course of the
project. Only upon seeing them assembled can you get
a true sense of their overall impact... how all of
the various pieces and small details work together,
visually. In the far lefthand photo of the second row,
you can see how the polished section of the engine center
cases visually match the chromed outers. The integrated
tailight unit sits on three billet aluminum mountings. The
front fender and oil cooler both received the billet mount
treatment as well; the cooler was mounted to a polished
aluminum spacer that lowers the front fender 1/4", giving
just enough clearance between the cooler and the headlight
shell. . The exhaust was designed for another model Honda
engine and the slight change in exhaust port location resulted
in the muffler being about an inch lower than stock.
We dealt with this issue on the shop bike by heating &
bending the headpipe slightly. We weren't about to re-bend a
$400 stainless exhaust pipe. So, continuing the defacto
billet "theme", we fabbed a rear mount for the muffler. Seeing
the wide tires on the bike shows just how much visual
difference that seemingly minor increases in section width can
make. The three tires in the photo are, from top to bottom:
OEM 4.00x10", the front tire and, on the bottom, the rear tire
actually used on the bike. The street tread will make a huge
difference in smoothness and steering precision. Lastly, the
drivetrain is capped-off with something not sold in the
US...an 18T countershaft sprocket. This is not something you
can slap on your 72cc stocker, but with twice that
displacement and four times the power of a stock motor, it's a
requirement to make use of the tuned engine's
power. |
    |
|
In these last four
detail shots you can see some of the subtle touches that set a
high-end custom apart. With the exhaust in place, it becomes
clear why the upper stay has a boomerang shape. We've seen
many custom bikes with extended muffler hangers but they've
mostly been clunky-looking , oftentimes looking like glorified
strap-hanger purchased from a hardware store. A simple, yet
graceful, curve capped-off with a polished stainless acorn nut
makes all the difference here. It took more effort, but the
result is cleaner and adds a natural bit of bling at
the same time. Likewise, we replaced the inspection screw on
the speedo drive with a hollow Allen-head bolt of polished
stainless. It's the little details like this that don't call
attention to themselves yet leave observers with the
impression that there's "just something extra nice about that
bike". We created our own side badges. Once again, aluminum
plate was used, along with basic graphics we created on a
computer. After polishing, the background was etched, then
clearcoated. The end result resembles cloisonne. Note the
German VIN tag, it's the original. The German market ST70 not
only had a different style plate, but it was in a different
location from those found on the CT70 model. It's also
interesting to note that the GVW is listed as 240kg...that's
528lbs! That makes Honda's factory-rated passenger
carrying capacity 372lbs(!) more than adequate for all
but the heaviest of riders and adequate for a medium sized
couple. The ST models were more road-oriented than the CT
models with which we are more familiar, but the rated GVW for
the CT70 was about half the ST's. This seems peculiar,
considering that the frames are structurally identical. Our
feeling is that the U.S. model load ratings had nothing to do
with the actual strength of the bike and everything to do with
governmental regulations in effect at that time. With the
power, suspension and brake upgrades we've made, GVW is a
non-issue. |
|
|
| |
|