shirley petchprapa

fabricator: SHIRLEY PETCHPRAPA

www.issaralabs.com / issaralabs@gmail.com / instagram.com/issarafree

917 482 4332

  • Custom hand shaped/formed tank - nickel plated

  • Custom hand formed tail section - nickel plated

  • custom swan neck clip ons - nickel plated

  • custom swingarm license plate bracket

  • Hand crafted Brass headlight ‘ears’

  • Hand formed fender

  • Custom pie cut 2-1 exhaust - nickel plated

  • New Wiring harness from scratch

  • Custom stainless steel rearsets

  • Brass turn signal mounts

  • and so many little details

moto guzzi v50 I (1978)

“big block envy” build story

To preface, this was my first complete bike build. I did not set out to build a bike. No prior experience and really no idea what I was doing. I was also only a handful of years into proper fabricating when it started (though had been making things my whole life). Prior to this build I had always modified my bikes. Personally never really wanting to ride a stock bike (no particular reason other than wanting a different outfit for the road). I was initially gifted this bike from a good friend one cylinder shy. I found a matching cylinder/piston, popped it in and rode it around in various visual iterations (small bolt on mods here and there) for awhile before it wound up with a crank damaging incident (long story) and sat indefinitely while my other bikes filled its spot. It was this delayed un-ridable state that inspired me to strip it all down for a frame powdercoat. This led logically (or illogically depending on who you are) to this idea of - hey, why don’t I just make some custom parts as I have no idea when I will find (or afford at the time) another crankshaft. The making part wound up being all of bodywork and a bunch of electrical and mechanical upgrades. I had plenty of other bikes to ride, there was no rush to get this one back on the road. And so it began!

Nothing about this build is perfect, nor is it trying to be. The whole journey was discovering and figuring it all out as I went. Very little to virtually nothing was planned, I designed as I went along.

To this day, this bike remains the most enjoyable ride in my fleet. So well balanced, agile, reliable with enough power to tackle the twisties around the Los Angeles mountains and beyond. I own a number of bikes, an old Triumph, old Hondas and a old/modern-ish CBR F4i (hardly modern at 20 years old but its the only carb-less bike I have) - and while its easy to jump on to the reliable once daily ride (CBR), I will take the Guzzi any day of the week and twice on Sunday! :)

As received. Completely stock. Thank you Gale!!

Sad crank

Guzzis are the coolest

Tractor clutch

Shown with an earlier tank design. I had added knee indents to the original tank and a fancy fuel cover. Had made a funny fiberglass seat and even sewed the upholstery. Torn apart and ready for powdercoat.

I had wanted to reuse this fuel cover but i just didn’t work with the new build

Early ILLY can oil catch later replaced with a proper oil breather from an El Dorado

I set out early to heavily simplify the wiring. I wound up whittling it down to a single fused system - with much less wires and for me, easier to diagnose and troubleshoot although I have had no issues with it to date. I drew up a new wiring diagram from the old and color coded it.

Kept the original Bosch charging system but updated to a Rick’s Motorsport regulator/rectifier to handle the charging amperage for the small Shorei lithium battery I decided to use for its teeny form factor and light weighted-ness.

18GA steel was my skin of choice

The seat came first. Pictured with an Imola V35 tank I sourced from Italy which I ultimately ditched to make my own. I love the Monza-style tanks and just love the proportions of the big blocks and how the seat hugged the tank. I knew I wanted that feature.

Feeling my way around metal shaping with a a couple of hammers and a sandbag. I finally caved and bought an import english wheel but the seat was finished by then.

Not a fan of discomfort and being a pretty small human (5’2”), I decided to make some goose-neck clip-ons by cutting up a pair of old handlebars. Many ‘cafe’ clip-ons have me aggressively bending over too much (small human, short arms)

Small brass mounts for the small front fender

Small front fender.

Determined to use the original petcocks and unable to source the proper thread pitch for the bungs, I had to make them. This may have been my first time using the lathe.

Cut with an ad-hoc die holder I managed to get it threaded.

Exhaust fit up

Cone Engineering muffler. The sound is amazing.

Decided to go 2-1 with the exhaust. Measurements and CAD. Using the original headers,

Brass headlight ears

Pie cuts are fun. I did purchase that ‘Y’ joint from CONE.

Literally forgot about the license plate and left with no room to position it under the seat, randomly came up with this side mount. Ive seen side mounts on modern bikes and thought it was clever.

HGXO1528.jpg

Had to remove the center stand to make room for the exhaust so had to make and relocate a new kickstand

Itty bitty turn signals.

It was about this time that I had done so much that I figured that I may as well make the tank as well. This is how you’re supposed to do it right?

Soldering cable ends for the carb cable Y joiner

Italian brake fluid tubing! Little details count!

Decided on a old style quick release BONORA Brevettato replica fuel cap used on 1950s Guzzi I believe

I was a newb to TIG welding and it shows….but I got it done and I’m a big believer of WABI SABI to be ‘perfectly’ imperfect hence the unplanished, hand banged look. It was actually intentional!

More or less done with the bodywork at this point and ready to polish for nickel plating. A lot of grits and elbow grease followed

I had cut down the shifter lever and moved it further back on the frame only to find out when I was finally ready to test ride it that I had ZERO leverage! The shift lever is that long for a reason! Engineering rules.

Mild steel to test the leverage and attachment points

Stainless version, could have come out better but it works and thats all that matters, I just wanted to ride it!

Temp foot peg replaced by Guzzi rubber later on. When you have a lot of bikes, you have random bike parts in abundance - anyone reading this Im sure knows what I mean!

Can’t forget the custom bike stand. If you spin those white wheels fast, they glow!

Cut cut some reflective tape for an italian lid (SUOMY) - although Im usually in my Shorei which also has its own Guzzi cut out. :)

An absolute JOY to ride.

The ONE Show in Portland Oregon right before COVID hit.

The ONE Show in Portland Oregon right before COVID hit.

Dedicated to the one i LOVE. I lost her in 2019 and have not been the same since..