MORE MAGIC REQUIRED

MORE MAGIC REQUIRED


MORE MAGIC REQUIRED

My over pressured fabricator in deepest California has stepped back from the Norton Commando,
and a triple of Bonnevilles all seeking the Master’s attention and the pre Christmas box is soon to be
opened.

Distant plans were the removal of the annoying Cub frame undertube, a reduction in angles for the
bash plate so that Super Cub would “glide” over things rather than hit them like a bulldozer and some
mini mods to other bits and bobs.

My original thoughts

Well of course all these “mods” are easy to say but unless you know what you are doing and how
you can achieve it they just become pie in the sky or a unholy mess of a bodge job. Clearly not the
case for Mastermind Ray.

The Tiger Cub being somewhat of the older design when trials bikes were converted road bikes
has that original under loop frame tube. The engine bolts up at 3 points, front, back, and an under
mount through that lower tube. Original back wheels carried the 3.50 x 18 tyre and space across the swinging arm was pretty tight for a 4 x 18 so various trialsmen went for a wider swinging arm unit
and put a spacer under the rear sprocket which in turn now required the same size spacers up front
to shift the engine over to line up. This causes the under side oil tubes a little grief up against that
lower tube and puts the exhaust very close to the front downtube. Trials back in the 60’s had a reg I
seem to remember stating no obstacle could, or should be bigger than 12″…… a far cry from what
we tackle today so bash plates were not a major consideration.

Back to the frame for a moment the lower tube is NOT horizontal when the bike is on both wheels
and dips down about 1.5″ at the front as can be seen in my pic of the bike sitting on a workshop
stand. With the bashplate level you can see just how much lower the front is.

With the bike in the “true” horizontal the front of the plate is too low

What then is the answer? The Novice designer, ie ME, wants the lower tube removed, the under
engine mount gone and the forward mounting point raised and replaced by engine plates fixed to
the front downtube which will tilt the engine backwards a few degrees and give the exhaust a little
more clearance. This will make it a lot easier to remove the engine, offer the option of using the rear
wheel spacer or not, and not have the oil tubes under constant pressure against the frame.

Need some simple front engine plates like the Armac design

Currently very little clearance for the exhaust

The bash plate can then be adjusted to either a shallower angle or a series of angles like the SWM
but I’ll put my money on Ray using a flowing curve……. whatever slips and slides!

Progressive curves and angles on the Jumbo plate

Can’t imagine getting stuck with this one

A couple of other minor mods are some stronger or bigger adjuster plates in the Ray designed
footrest mechanism as the current ones have bent in action.

Needs to be bigger and thicker

Last mod in this go round is a slightly bigger access hole in the frame where I mount my top coil. The
mental and physical gymnastics trying to get that coil in the hole would try the patience of a Saint and
on my track record I’m leaning the other way!

The “Hole” of frustration !

That’s what we have and my thoughts on what I need, so now time to sit back and see what the
Uri Geller of frames and bash plate bending comes up with.

TONY DOWN

What did you think of this article?



Trackbacks
  • No trackbacks exist for this post.

Comments
  • No comments exist for this post.
Leave a comment

Submitted comments are subject to moderation before being displayed.

 Name

 Email (will not be published)

 Website

Your comment is 0 characters limited to 3000 characters.

 



  

Leave a Reply

Your email address will not be published. Required fields are marked *