Tuesday, June 5, 2012

The mock-up, part 1.

So, let's take this nice and slow.
Day two of the mock up starts with a big heavy chunk of octagonal brass that Peppe turned on the lathe to make a steering stem nut. This solves the problem of the mismatched thread and looks pretty neat:

 You may remember there was another issue with the steering stem: basically the neck is 1970 spec. and the stem itself is 1971 on, so a couple of spacers had to be machined:

The tattoos on the upper right arm are of the Archangel Micheal slaying something and the motto "si vis pacem para bellum" (if you want peace, prepare for war). Underneath, another motto: "in dogs we trust".

The spacer is held in place with a grub screw.
Not bad huh?
Next, more spacers, this time much larger and made of Teflon, also held in place with a grub screw. These are a tight fit on the stanchions to provide an attachment point for the gaiters.

Time to get the new tyre on:

The tattoo on the left calf is of a winged naked blondie with the motto "man's ruin"

Always nice to see how much new tyres change the look of a bike.

Sparks flying. This is a good sign and has been a recurring scene over the past few days. In fact, the bulk of the work has been metal fabrication, cutting, grinding, shaping and welding. Day after day. Peppe works fast because he has a long line of bikes waiting outside his workshop, but that doesn't mean it's sloppy work: everything went very well.

Above: the support for the oil tank is being cut to size, ready to be braced and welded on the frame.

The tattoo on the right calf depicts a cobra coiled around a 'V8' symbol, with the motto "bigger is better"... Peppe does have an AC Cobra but.... oh dear.

The oil tank is rigidly mounted so these welds have to be solid. This area of the frame will evolve to include the seat support and I can tell you it came out absolutely bullet-proof.

 Ok, now for the rear wheel spacer. We start from a big chunk of aluminium:

 And after a lot of work on the lathe...

We get an Apollo-capsule-shaped bit of awesomeness:

Starting to think about the battery:

And winding down for the day.


RapidRoy said...

Not sure I understand how the upper steering stem spacer works in conjunction with the steering stem nut you fabricated. Normally, the stem nut bears on the upper bearing itself to tighten the steering head.You appear to have locked the spacer to the stem with a grub screw. It looks like the new nut bears on the spacer. Am I missing something?

Artie said...

Hi RapidRoy, so, the spacer and the brass stem nut don't actually work together: the spacer is there simply to solve the issue of the OIF stem being too small for the 1970-spec steering neck; it is indeed locked on the stem with a grub screw.
We measured and positioned everything so that the nut wouldn't come in contact with the spacer: I realize now that I didn't take a photo showing the final fit of those two parts, but basically the nut does not touch the spacer.
Also, we used "cup-cone" type bearings, something else I didn't really show... just too caught up in the excitement I guess : )

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