Modern Vespa

Hey guys
So I got a 1959 Allstate with serious racing upgrades, including 4 gears instead of 3. The original shifter tube was not made for this setup.
Tried to get the SIP "short shifter" but it doesn't look like anything they have would work with the split headset.
I'll post some pictures..
First, the original tube.

The original cable adjusters were 1/16th mild steel, brazed to the tube. I knocked them off using a Mapp gas torch.

I have access to a CNC machine (waterjet). I made my own shifter CNC program and cut two 1/16 discs and one 1/8th spacer. Two 6mm screws hold them together.

Shoulda brazed them to the tube, but I felt more comfortable welding. Not the best idea but it worked.
The "feel" through the gears is night and day. Shifting-through-neutral guesswork is no more.

Very nice Ray! I've got a 62 Allstate that has the same split headset and three speed shifter setup. Moving the cable ends closer together instead of opposite each other makes shifting easier and smoother?

That looks like a fantastic upgrade I wouldn't mind doing to my stock setup!

I also looked into the SIP short shifter to install on my 61 Allstate, and yeah, it won't fit in the split headset. I currently have a P200 engine in my Allstate. You didn't happen to make a second short shifter did you?...because i'd really like to get something like that on my scooter.

Ray - this is awesome.
Those water jet parts would make great stocking stuffers for a few of the guys on here I’m sure!
Perhaps you can be convinced to cut a handful of extras.

Wanna c the rest of the scoot now!
-CM

I’d possibly be in that boat for wanting some of this action too!

Great job! I miss projects like this, there fun. I use to work for a company that had a complete building devoted to R&D, 200,000 square feet. I took a few Solidworks and CNC courses at my local community college and I was allowed to work on projects like this in the evening. My favorites were a laser cutter and a wire edm.

What was the diameter change?

I think he increased the diameter of the shifter cable holder in the middle area. It looks like the original may have been the two sides capturing the cable ends and the cables wrapped around the tube. He made new ends to capture the cable and a larger diameter center for the cables to ride on. The outer now turns more for the same movement of the bar.

I used the original diameter, around 42mm. The difference between the new disc and the old pulley is the diameter is constant in the new setup. I'm not an engineer, but that seems to be one reason why it feels so much better.

Quick update.
Been riding with this new setup for a month or so. If you have a 4th gear upgrade, IMO it's a must-do if you live in an urban area and want better confidence in traffic.
I emailed SIP and they sent me their option for the split headset. Just couldn't see how it could work from the pictures of those parts on a split headset tube.
I'll post an AutoCad file, in case anyone has access to someone who can cut these for them.