How This Ridiculously-Slow Moped Set Three Speed Records At Bonneville Salt Flat’s ‘Speed Week’

Solex Ts
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The annual Speed Week event at the Bonneville Salt Flats is host to some of the fastest vehicles on earth. Every year, about 550 vehicles of all descriptions gather to see who can go the fastest over a straight-line course that usually measures about nine miles long. In a normal year, there will be two courses set up more or less parallel with each other. Unfortunately, this year’s event was a little different because the weather left so much water on the salt that only a single, shorter course could be created. This kept the top speeds down due to a lack of run-up space, although a slippery car called Speed Demon was still able to set a top speed for the meet of 333 mph.

While everyone loves seeing the big boys hit those ridiculous speeds, the star of this year’s show couldn’t even go 1/10th that speed. It was a 1955 Velosolex 49 cc moped (known simply as a Solex back then) brought by the Carre family from France. They managed to set three different speed records.

The Solex

Solex Moped
Photo of a Solex, via Bonham’s

Before we get into the records they set, let’s look at what a Solex moped actually is. The Solex company was founded in the early 20th century by Marcel Mennesson and Maurice Goudard to manufacture radiators for various vehicles. This lasted until the end of World War I when the radiator market took a downturn for Solex at which point they bought the rights to a carburetor design patented by Jouffret and Renée. This was the start of the famous Solex carburetor which found its way into many European cars over the years and can still be purchased today. The company went through a number of changes and acquisitions over the ensuing years and is now part of the Italian company Magneti-Marelli.

During the early part of World War II, the company began experimenting with a motorized bicycle using a 49 cc single-cylinder 2-cycle engine that was attached to the handlebars and drove the front wheel directly via a friction wheel pressed against the top of the tire.

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Here is what that early bike looked like.

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Notice the toothed wheel, up under the small fender, that rode against the front tire and powered the front wheel. It was a very simple design; there was no clutch, you just raised and lowered the whole motor assembly onto the tire via a handle at the top, and you started it by peddling while the “clutch” was engaged.

The design proved to be extremely popular and the Solex was produced from 1946 until 1988, with various upgrades along the way, including the introduction of a proper automatic clutch in 1959. I remember growing up in Holland during the 60’s and seeing many of these on the roads. They were cheap, easy to maintain and perfect for city and small-town use.

The Speed Week Solex

As you might expect, these are not speed demons. An original Solex has a top speed of about 22 mph, which is not going to make a very good impression at Speed Week. No, the owner of this Solex, Stephane Carre (pronounced “Stay-fahn Car-ay”) wanted to make a stronger statement, so he took a 1955 moped and turned it into a proper Bonneville racer, complete with lowered handlebars and a blower!

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Look at that thing! It’s awesome! And it was the star of the show. Helped along with his wife and crew chief, Veronique Carre, and daughter Ivana Launay, Stephane went on to set three separate speed records. He did this by making only a few changes in order to qualify for three different classes. The first record was in the M-VBG (Modified, Vintage, Blown, Gas) class and he set a speed of 30.866 mph. Yes, you read that right, thirty point eight six six miles per hour! He then added a fairing and shield around his legs and the bike became a partial streamliner:

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This put him into the MPS-VBG (Modified Partial Streamline Vintage Blown Gas) class where he set a record of 26.655 mph. Don’t ask me why this one was so much slower than the previous speed. Maybe the streamlining actually slowed him down or maybe the salt was just different that day. I don’t know. In any case, he came back later without the streamlining but with “fuel” in the tank (which means anything other than the approved gasoline supplied at the race: alcohol, nitrous oxide, E85, hydrogen, nitromethane, etc.) and set another record in the Modified Vintage Blown Fuel (M-VBF) class at 29.782 mph.

Check out two of his runs and listen to the sound this tiny engine makes. It’s just too cute to sound so angry!

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I spoke to Stephane’s daughter Ivana Launay and asked why bring this vehicle when they are surrounded by V8 powered monsters and superfast bikes, and she gave me a look of pure pity as if to quote that famous Harley-Davidson saying “if you have to ask, you wouldn’t understand.” But, she didn’t say that, instead she just said “because it has never been done before.” I can’t think of a better reason than that and I had to remind myself that they were out there on the salt setting records while I was just watching and wishing I was out there with them.

That sort of can-do attitude and the fact they made it happen is what Speed Week is all about and it made them the stars of the show. Everybody, even the crews for the big boys, came out to watch Stephane make his runs and cheered every time he got under way.

All in all, it was an amazing week made even more amazing by a French family with a love of speed, even if that speed is little more than most people drive around their own neighborhoods. I hope Stephane is back next year and keeps setting records along the way. Who knows, maybe someday he will even break the magic 40 mph line!

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65 thoughts on “How This Ridiculously-Slow Moped Set Three Speed Records At Bonneville Salt Flat’s ‘Speed Week’

  1. I had a 49cc 1978 Honda Hobbit moped. I removed the intake restriction, and changed the fuel oil ratio from 25:1 to 50:1 using Golden Spectro, and I easily got that to 30mg without fairings or superchargers. Now I wanna race!

  2. One of the main forgotten joys of the Solex is that when the engine inevitably seizes some day, it locks the front wheel and sends you flying over the handlebars

  3. Some little engines do amazing things. There’s an old video on YT of a guy with a hilariously modified 50cc pushing an ultra-slick streamliner all the way to 150mph. He needed every inch of the entire run, even through the flying mile, to get to that.

  4. last year as a tribute to his friend (Fiddy) who killed himself due to mental health issues, the mechanic who redid my Trail 90 for my daughter set a speed record for a Honda 50cc. Hilarious but also kind of cooler than some crazy thing going over 300mph

  5. Bonneville was an awesome experience. When I was living in Denver, we (my family) did a two week car trip. So Denver to SLC on day one and then to Bonneville. Talking to the folks doing things in the smaller classes, trying to get the most out of small displacement was the most fun. Most everyone there was pretty jovial, even when fixing things found in inspection. Getting salt off the car afterward in Wendover, not so much fun.

    After Bonneville, proceeded west over a few days through Yosemite over to Gilroy which is as close to the Monterey events as we could afford hotel wise. Took in several events, Friday at Laguna Seca, the little car show, d’Lemons, etc. Went home via Reno and hit the Harrah’s collection museum. Great trip. If I had it to do again, I’d have scheduled more time at Bonneville.

  6. I would like to see more fairing equipped small displacement motorbikes make runs there. World’s Fastest Indian? Well, no, World’s Fastest Tomos.

  7. Not going to lie, setting a Bonneville record for stock Renault 4 GTLs is definitely on my if-I-ever-get-crazy-rich bucket list. Why? Well…

    Because it has never been done before.

    (The 2011 237km/h run with a 4F doesn’t count; for starters, it’s a 4F, and also, far from stock)

      1. I mean… the record isn’t really essential, but it would be a nice absurd touch. But I really want to take a stock Renault 4 GTL to Bonneville one day.

    1. There’s a shitload of Solex mopeds for sale in online marketplaces here in Portugal, which is odd because they were never that popular around here. Back in the day, Peugeot and Motobécane had the local moped market pretty much cornered, and my theory is that the moped renaissance from the last 20 years got some people “importing” them for cheap hoping to make some money flipping them. The problem is most moped aficcionados are not into Solexes, and would much rather restore one of the many cheap, roadworthy Peugeot 102/3/4 you can still find around here (and for which there is a never-ending supply of parts, unline Solexes).

  8. the start of the famous Solex carburetor which found its way into many European cars over the years

    Perhaps most famously it was the OEM carb in the VW Beetle – the 30PICT and later the 34PICT IIRC.

    There used to be an aftermarket dual-carb setup for VW engines called the Kadron kit: it contained two 40mm 1bbl Solex carburetors and would really wake up a stock Beetle.

    1. I had the dual 40 Solex set-up in a late ’66 Squareback–first VW with fuel injection, IIRC. Carbs were far better, but the rear deck was no longer flat.

      I had twin Mikunis–I think something ridiculous like 80s?–on an early ’80s Yamaha Vision 550. Ran like a raped ape until it didn’t. I never before or since had a motorcycle where the entire thing wore out all at once!

  9. As with all racing, start with the rule book. I’m guessing this was a class that nobody had tried before. If it’s purely 50cc and doesn’t require pedals an old 50cc GP bike from Kreidler or Derbi could hit at least 60-70 mph but as full featured motorcycles they may be in a different class. This still leaves an opening for a more advanced moped like a Yamaha FS-1E.

      1. So you do know more about the classes? More would have been helpful in the article.
        Of the three classes he was in, what exactly do the class names mean, what else qualifies for those classes, and what speeds did they achieve?

        1. I don’t know any more about the classes except there are a gazillion of them. This year there were numerous vehicles running in “open” classes, meaning no record had ever been set in them before. Strange to think that after all these years (decades even) that there would still be open classes but folks constantly come up with strange new vehicles that don’t fit into any of the existing classes so a new one is created and they get to set the first record.

  10. That thing is adorable, and I don’t mean that in any kind of condescending way. Are there gears/a transmission between the engine and the drive wheel, or is it just a direct connection between the two? I’m assuming the latter, since it’d seem possible to go faster than 30MPH if you could shift into a higher gear once in motion.

    To me, this is much more interesting than the supersonic stuff. 😉

    1. The Solex engines did not have a transmission or gearbox. The friction roller that contacts the front tire sits right on the crankshaft. Later versions put a clutch between the crankshaft and the roller but it was still direct drive once the clutch was engaged.

      1. Hmmm… that’s interesting. I presume that during development, they tested drive wheels of varying diameters to get whatever ratio was most useful for a speed run.

    2. It says in the article it’s a simple single-cylinder 2-cycle engine spinning a drive wheel. The “clutch” is merely dropping the wheel onto the top of the wheel.
      I presume that the engine RPM is controlled by a throttle that the rider maxed out on the run. Any other gearing would potentially damage engine.

  11. The French have always been masters of winning through rules exploitation. They put themselves in charge of the FIA and created the Index of Performance so their tiny underpowered cars could win something at Le Mans. Until Colin Chapman beat them at their own game. And then there was that thing with the Germans…

    Excusez-moi Monsieurs. We must protest. It is clearly against the rules to go around the Maginot Line.

    1. ya know…i’d always heard that France in 1914 was still steamed about the Prussians in 1871, and also that the reparations Germany imposed on France after that war were far greater than those imposed on Germany by the Allies at Versailles…but i just recently learned that France invaded and occupied part of the Ruhr in the 1860’s. Bismarck and the King Bill Deuce may’ve been dicks, but the French weren’t innocent victims either.

  12.  2-cycle engine that was attached to the handlebars and drove the front wheel directly via a friction wheel pressed against the top of the tire.

    What an aggressively French way to make something go.

  13. That’s cool, but can someone explain exactly what the class names mean, what else qualifies for those classes, and what speeds they achieved?
    As written, a 30mph record doesn’t make sense to me.

    But hey, as you said, it’s really cool that he and is family were out there doing that together.

    1. Yes probably different classes, they have scrillions of them, I think.

      I redid the engine on my brother’s 49cc Motobecane and it managed 53 mph on the road @ ~800′ altitude, speed estimated by a car running along side. Not blown just air sucked through a chainsaw carb, cylinder porting and piston hacking by a me, a small expansion chamber globbed together and lots of noise. The low end torque was supplied by pedals. It was a lot of laughs for my brother a couple of days and then it suffered catastrophic engine failure. I guess kids don’t read Gordon Jennings “Two-stroke Tuners Handbook” anymore. (-;

      1. Have you learned more about expansion chambers since then?Would you be prepared to guess how good that one turned out? How close to optimum it got?

        I’ve modified a few but never built one from scratch

        1. I probably understand them better and there are more resources out there I think these days, but soon after that I was forever sidetracked by 4-strokes.
          That one was far from from optimum the “design” was limited by the carburetor which was moved to the front of the cylinder adjacent to the exhaust port, it had to run under the bike the pedals had to work for it to be somewhat legal on the street, the thing was 18 gauge sheet metal because that’s what I had, the stinger was a handy pieces of tubing with a hose clamp for tuning. I remember it was nasty cobbled together and I painted it flat black. It was welded with IIRC a solidOx torch in my parent’s garage close to 50 years ago.

    1. And they do that for many hours at a time, every day of the week, for weeks.

      I ride for fun and can cruise between 15 and 20 MPH. I can easily do 30MPH. I can’t hold it for miles. But it’s not hard to get there for a little while.

    2. The current 1 hour record for cycling is over 35 miles. This is on an indoor track rather than salt though. It’s not very hard to beat 30mph for shorter distances.

    3. Of note this is over the coarse of thousands of miles, up mountains and having your co-workers block the wind.

      A better comparison would be Flippo Ganna’s Vuelta Espana time trial two days ago. On flat 26k, smooth course. The best time time trial rider on earth (sry Remco fans), with a UCI legal bike average 56kph or 34 mph.

      If we were in theory take Flippo Ganna and have him ride the salt flats. We could gain some speed as no UCI rules opens the possibility of using the wacky world of triathlon bikes. However, friction loses though the tires would be much high then the average of 7-9 watts for a top tubular.

      Overall, as long as the bike doesn’t sink into the salt, I would guess a decent cyclist (4.5 w/kg ftp) on decent TT bike could easily beat this thing in a straight up race.

  14. Is it the underdog appeal? Maybe it’s just the aspiration to do things in/with inappropriate vehicles, but this sort of thing speaks to me: “Come on; you can hit 30…come on!!”?

    1. I mean, claimed 3 records. That is by-the-rules the definition of doing it right.

      if we went through history to see how many other entrants claimed 3 records in a single year, they’d probably be extremely few and extremely crazy.

      1. You have a point. I’ve never had to rely on a moped, but have been pitifully underpowered until the last few years, so urging the underdog forward is kind of built in.

    1. Unfortunately, you can’t get close to the track at the points where the cars are at top speed. You’re about 1 mile away at that point so the view is a bit limited.

  15. On the more modern end (and b/c at least Mercedes and I are fans of the marque), awhile back a lowly Buell Blast likewise set a couple of motorcycle class speed records. Wasn’t even particularly modified either IIRC. Made me happy that someone would put in the time and effort on such a modest (but cool) bike.

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