Modern Vespa

I decided that it was time for a few upgrades for my '85 PK125XL. The engine is still all stock (for now), but I wanted to improve the front brake as well as the headlight.

We'll start out with the front disc...

Bolting a Grimeca disc on a 20mm fork is fairly straightforward, so I won't be going into any details about that part of the project. But bolting a hydraulic brake master cylinder to a non-disc headset isn't as simple.

Here's a pic of most of the parts I'll be using. You can also see in the pic where the perch for the front brake lever has been removed.

I used a piece of 3/8" aluminum angle for the perch bracket.

I drilled and tapped the holes for the master cylinder before I started welding.

After a few passes with the spool gun.

And after a few passes with the grinder, it's looking a bit better. And if you look really close, you can see the Time-serts that I installed in that bracket.

And a side view.

I also removed the front fork for a few reasons...
#1, I wanted to grease the upper and lower steering column bearings. The upper ones were dry and rusty.
#2, I wanted to paint the front fork.
#3, I installed a different front fender that I already had (that wasn't dented).

A picture of the fork after it was painted.

I wired in a front brake light switch since the PK didn't ever have one.

I had to notch out the headset cover for the brake line to fit.

Now on to the LED headlight that will be installed on a non-battery 12VAC system. Since LEDs don't like AC power, i'll have to somehow get DC power to the headlight. Normally on any of the vintage bikes that have a battery (P/PX/LML Stella), floating the ground on the stator then adding a DC regulator is how it's done to get DC power to the headlight. A different route needs to be taken when there is no battery to wire up the LED to...

Here are some of the parts that I gathered up. All of the plastic was found at Tap Plastics. I think I paid about $10 for all of the plastic that I bought.

I spend quite a few hours figuring out what diameter and thickness I wanted the plastic to be. I made a few different sizes and colors for experimenting.

I used the router to countersink the bezel of the LED into the HDPE black plastic...which in turn, that bezel will get "sandwiched" between the outer white colored piece of acrylic plastic

When mounted together, it looks just like the light in this picture. It's a fairly thin profile.

I got some brass threaded wood inserts. They will be used as a pivot for the light assembly. I drilled a hole in the HDPE, and screwed them right in.

What it looks like threaded in.

After I very carefully measured exactly where I need that threaded insert placed, I screwed in a stainless steel Allen head cap screw. That cap screw will act as the pivot for the light assembly.

Now onto the wiring...
Very sharp viewers will notice that the headlight wires are coming from the left side of the headset. That's because here in America we have our headlight switch on the left handlebar (turn signals on the right side). I wanted my PK to be like my other scooters so I swapped sides with my switches.

Since I won't have a dimming capability with my LED, I will only be using the purple highbeam wire and a ground wire from the switch. I removed the brown low beam wire along with the white pilot light wire.

The wires I have left coming from the light switch are a purple and black. You can also see that I have drilled about a 3/16" diameter hole in the headset. That hole is there to bolt in the AC to DC converter box.

A picture of the box bolted in, and wired to the LED light.

And plenty of room for the converter box and the headlight.

Here's what it looks like installed. I still need to make a third attachment point for the headlight assembly. That will need to be done at night, so that I can properly aim the light.

Fast forward 24hrs later...

I figured out exactly where I needed the third mounting point. I made a little L bracket that will be used, as well a two more of those brass threaded wood inserts.

I used a drill bit stop so that I wouldn't accidentally drill all the way through the plastic.

Here's a pic of the L bracket once it was modified and painted.

And a few more pics of the scooter with it all buttoned up.

A front view, right before the unveiling of the new headlight.

...and the final product.

The LED definitely changes the whole looks of the scooter. I would be nice to have a light that is more "classic" looking, but having a bright headlight for me at night is of the most importance for me. There are LOTS of deer and a large herd of elk where I live. I don't want to hit another one.

I can't think of any downsides for me installing the LED in my PK. I used a Baja Designs S2 LED that has a "wide cornering" lens. It has a little bit better of a light cutoff, compared to some of their other lenses. The LED does flicker some at a very low idle. If the throttle is opened to about a 1/16 of a twist, the flicker goes away. I spoke to Baja Designs about this, and they said that's just how the converter box operates. It's not because there isn't enough power from my stator, it's just how the box is designed. They assured me that it won't cause any damage to the LED.

They are right. I also have an LED headlight and it blinks a little on idle but if you adjust the idle it does get better. I've never had issues with my leds

Nice work as always WDC. How do you find the spool gun to work with? I bought one but haven't gotten around to hooking it up as yet.

I have a 260amp ESAB MIG welder. About a year after I bought it I purchased a ESAB spool gun for it. It's just an OK gun, it's nothing too fancy. I had a difficult time figuring out what to adjust the controls to. After a friend came over and gave me a baseline to start with, I then started to lay down some semi-decent beads.

...and I spy a white '09 990 that's hiding behind the freshly painted fork?

Ha,Ha! Good eye Dado, i didn't realize that the bike was in the pic! I don't ever get alerts when someone responds to any of my postings, so i never saw your message.

That is actually my friend's 2013 990 Baja. I do all the maintenance and upgrades on his bikes. I might have been installing heavier springs in his forks at the time? I actually found that bike for him on craigslist. He was after one for years, and this one had about 5000 miles on it. He and his wife flew 2000 miles to get the bike, then rode it home!

I have a handful of orange bikes...and one big blue '06 950A. I just had the suspension tuned (and raised up to a 265mm suspension) last Thanksgiving time, and it's set up REALLY, REALLY well for desert racing right now! I have two races coming up this April, so i'm going over it with a fine tooth comb in preparation...along with kitting and rebuilding the red PK's engine. I figure that if i can now stop fast with a disc brake conversion, i might as well make the engine fast too. One can never have too many projects at once!