Rick Onanian <
[email protected]> wrote in message news:<
[email protected]>...
> On 24 Jan 2004 09:50:11 -0800,
[email protected] (Carl Fogel) wrote:
> >But the integrated skid plate stopped short, leaving the clutch arm exposed underneath the
> >motorcycle!
> >
> >True, extending the skid plate to protect the imbecile clutch arm underneath the engine would
> >have required removing the whole engine from the frame just to replace a clutch cable, a bad idea
> >in the shop and even worse in a muddy field.
>
> Maybe there's something I don't know about motorcycle skid plates, but couldn't that spot be
> covered by a removable, bolted skid plate?
Dear Rick,
Not easily, not well, and not economically.
Something about 400 pounds of rider and machine banging over three-foot logs just doesn't like cobbled-
together rear skid-plate attachments. Things flex and even bend permanently down there.
Even if attached, the secondary skid plate would be almost guaranteed to form a lip under impact
that would snag more badly than the empty space and somewhat recessed clutch arm.
God knows we tried to fix things.
In Colorado, we modified Bultaco Sherpa T 326 machines with a hideously ugly but effective trick.
We cut Preston Petty unbreakable plastic front fenders in half, welded stout nuts inside the skid
plate, laboriously crushed the fender halves into place with huge C-clamps, and used the biggest
round-head bolts and washers that we could find to attach the fender halves lengthwise under the
skid plate.
The crude plastic armor had more give, slid a little better, reduced ground clearance only half an
inch, and wrapped around the engine cases a bit to provide far more protection.
At the start of a season, you could stand on one of these fender halves without bending it
appreciably. At the end of a season of smacking into rocks and logs, the same fender half would flop
like a basset hound's ear.
When I replaced my fender armor in 1974, my down tubes were revealed and turned out to be badly
dented. It's nice to have the extra strength of the transmission functioning as a frame member. (The
contemporary Ossa machines lacked down tubes and relied on the gear case for the lower part of the
frame--lighter, a bit more clearance, and so forth.)
Most manufacturers moved to wraparound, removable skid plates that moulded themselves around the
bottom of the machines, attached by a bolt high up in the front and by various schemes in the rear.
Honda used a metal version, while Yamaha came with a fiberglass model.
I broke three of the Yamaha plates one afternoon when Yamaha was foolish enough to invite some of us
to demonstrate their trials bikes by riding over some handsome logs at the Denver fair ground. (The
proverb about riding gift horses to death applies.)
All three of the fiberglass skid plates broke at their back attachments, right where you quite
naturally wondered about attaching a removable skid plate. It turns out that you want a long,
smooth, stout skid plate attached as high up at both ends as possible.
All that protected the nuts on our dreadful fender-halves was the upwelling of incredible plastic
fender material around the nuts--no scars were left on logs that we teeter-tottered over because the
plastic didn't give enough for the round bolt heads to touch the wood.
Carl Fogel
