Employee/Author: Cory Mezzenga
Editor: Art Petrakov
Cars? Yeah I’ve had a few of those. I’m no stranger to fun cars, in the last few years I’ve had a Mazdaspeed Protege, a 2001 2.5RS sedan, a 2002 Bugeye Wrx, a Volvo 240 (more fun than you might think), and a built Outback XT. More recently, I’ve purchased another fun project, my first house! With that, my fun car budget pretty much became non-existent. However, anyone who loves engines can’t stay away from getting their hands dirty for long, and besides I’ve been on two wheels longer than four. Sure, I could’ve gotten a motorcycle, but I wanted something a bit different. When people hear the word “moped” they think a scooter that zips around college campuses across the nation, but not these mopeds. The real mopeds, with PEDALS attached to them, that’s the bike I wanted to build, to make stupid-fast, for stupid-cheap..or so I planned.
I’ve been working on this moped for over 6 months now and in that time it’s gone through some crazy transformations. Originally this build started as a Garelli SSXL Moped with a 70cc kit, a bigger carb., aftermarket pipe, etc. At that point, the only thing that hadn’t been modified was the tank. Unfortunately, the reason I decided to modify anything on this bike is a bit of a bummer. Aptly named “The Spite Bike”, the main reason of this build was actually to upset the person I got it from.
Now, I know what you’re thinking, why would anyone do that? Well, let me tell you. I traded a bike that I very much enjoyed (which ran fine, was reliable, fast, and rare) for this to a (now ex) member of the local moped community. I had seen the bike on weekly rides so I was under the impression that it was in comparable condition to my own. When he arrived to my house on the day we were trading, he couldn’t get the bike to start, I attributed the issue to the cold day (modified mopeds are notoriously finicky in cold weather) and just said it was fine. He assured me it ran great and was in excellent condition engine-wise. Well, that’s where I got taken for a ride, so to speak. After doing everything I knew to get it to run, I finally decided to crack the cylinder off. Welp, the piston was smeared on the cylinder, meaning it ran lean, overheated, and the piston jettisoned some material, leaving a bike with no compression and bits of metal in the case. Well then, that’d do it I suppose! I shot him a message about what I found and he told me to get lost.
Delightful. So there I was, stuck with this thing, suddenly having to throw more money than expected at it. Looking at the engine it came with, there were many shortcomings in the original design, especially when it came to modifying it. Weak clutches, very little aftermarket support, and just general performance potential left me looking for other alternatives. Originally I decided I was going to slap on a 140cc pit bike engine and call it a day, but after looking at the bike and how the pit engine would mock up, I elected to stick to the moped roots with a 50cc 2-stroke.
With aftermarket support and power potential in mind, I decided to go with a French heart for this “phoenix out of the fire” reborn moped. French bikes like Peugeot and Motobecane use a variator instead of a gearbox. Essentially it’s a small CVT transmission, belt driven with a variable pulley. This is a perfect setup for mopeds, as their low power output and static power bands really benefit from a drive system that can utilize the maximum power at any given time. After about 15 minutes of research the Peugeot came out on top for a few different reasons:
First off, Motobecane engines are more vertical whereas Peugeot uses a more horizontal engine configuration. Perfect, as I needed to tuck it somewhat in the same place where the original engine went under the frame.
Second, the Peugeot used a swingarm engine mount, which means mounting it to the bike would be very easy. No messing with chain lines, no weird suspension geometries, it was pretty much all done for me. One mount on the frame, aligning the shocks, and we’re golden!
Luckily there is a company that makes a mount that you can buy as opposed to either cutting up an old Peugeot or making your own. I decided to run KX80 Dirtbike Forks so I could have a disc brake up front, painted the tank, and made my own custom seat. Now it was time to weld things up. I can weld, but I don’t have a nice setup currently, so I enlisted the help of my good friend Tyler (an Aerospace Welder by trade) and his equipment to help me get this thing [literally] rolling.
Now it was time for the powerplant. I bought a used engine which turned out to be trash (I’m getting so lucky with this build, right?) This was the point I decided to make this bike a real financial mistake, more so than what it already was. As you can imagine, performance parts for a 27 year old French moped are hard to find, and when you do, they aren’t cheap. “But if i’m going to do this,” I thought, “I’d better do it right”. Garelli was an Italian manufacturer and as it turns out there’s another company in Italy that makes performance parts for all makes: Polini. Even though the engine is a french design, most of the parts I would be using were Italian, paying homage to the original Italian heart of this bike.
I sourced a Polini 70cc W-Port Kit, Artek Stuffed Crank, Polini Race Cases, 4 Petal Reed Block, and a Dellorto PHBG 19mm Carb to top it all off. It’s always fun to watch the boxes of parts come in, as much as it may have hurt the wallet:
Originally I had decided I wanted to make this bike really, really obnoxious, so I was going to do a watercooled kit, but the customization I’d need to do so was a little too intense for my time constraints. Here you’ll see the crank and stock variator installed with engine mounted on the bike:
Since I deviated from my original plan of keeping it 50cc, the 70cc piston was larger, requiring some custom milling to the head to allow room for the piston:
Next, I had to source some shocks with the correct length to give the bike a good stance, without being too raked in either direction. You can also see the entirety of the wiring for the bike, quite a bit more laid back than doing a custom harness for a car.
In conjunction with the 70cc kit, I decided I wanted a big exhaust pipe. This pipe “hits” at about 7500 rpm; you can liken a 2-stroke pipe powerband to that of a turbocharger. There is some lag in the low end, but when you’re on the pipe the bike just absolutely wants to scream (sounds clips to come!)
With a kitted motor the stock variator just can’t handle the performance and must be replaced if you want to get anything substantial out of the bike. The Doppler ER3 Variator has adjustable weights so you can essentially “set your gear ratio”, or pick when the pulley moves based on the centrifugal force of the weights.
With all of the mechanical aspects of the bike complete (for the most part, as the bike is still being tuned) it was time for some cosmetic touches. Restoring the old speedo gauge, cutting some tank badges, and vinyl for the top that reminds me to persevere with the build:
The bike still has a long way to go, but this should give you a good teaser of what the finished product will look like. Future plans include a computer for logging data, speed, tach, odometer, etc. Wheels need powder coating, lights still need to be wired, and the variator/carb. still needs tuning. The fork will need to be shortened a bit and filled with fluid, the pipe hits the ground on sharp right turns so that will have to be addressed, and foot pegs need to be figured out, amongest a long list of other details. No matter, because half the fun of this is in the build itself; keep a lookout for updates on this and more of my projects to come!