About Cycle Karts

Cyclekart is a type of kart racing where you drive what basically is a motorized soapbox car.

The mechanical design is a simplified version of a cyclecar. The formula specifies that a cyclekart is a one-seat car using Honda 17 x 1 3/4 or 2 inch rims, 2.50 x 17 tires, a 38 inch track, wheelbase as close to 66 inches as the aesthetics of the car will allow, weight no more than 250 lbs, and powered by a 200 cc, single cylinder, 6.5 hp Honda OHV engine (the GX200). A cyclekart should not cost more than $1750 to build in 2001 dollars and the driver is required to build his own car. Power is transmitted via a Comet TAV-30 unit to one wheel only. Braking is also on this same rear wheel by mechanical Comet disc.

Cyclekarts are generally styled as 1920s and 1930s race cars.

-Definition of Cycle Karting as described by Wikipedia.org.

In Pursuit of Cycle Karting Excellence

Cycle Karting has received a brief flurry of attention recently on the interwebs, I believe beginning with a Make blog post, and then followed by numerous other blog posts from Jalopnik, Dude Craft and others. Each entry, despite giving Cycle Karts appropriate respect and appreciation, only drooling observations about Cycle Karting and don’t actually execute Cycle Karting excellence like the actual Cyle Kart creators and innovators at the Association of MotoCycleKartistes (AMCK). It was during that flurry of attention that I was first introduced to this most excellent Cycle Karting concept and shorthly there after I bought CycleKarting.com and began brainstorming.

My Own Pursuit

Like the blogs above, I too suffer from only being able to make drooling observations, so I am confined to an innate boyhood-like fantasy to build one for myself, which I hope to build in the coming year. I am a web developer and designer and although I don’t have the time to build one immediately, I find myself committing any spare time to thinking about proportions and mechanics. As such, the journey has begun.

The Start

The Start

This site is deliberately void of photos of Cycle Karts as a means of motivating me toward getting mine built. In the meantime, I sketched the Cycle Kart above as a “first draft” of what I anticipate mine looking like, maintaining historic “Cycle Car” proportions and elegance.

Looking Forward

The AMCK is based in California, so I would like to gauge any response on the east coast, particularly in Central PA., so…
holler in the comments if you are Cycle Kart crazy.

This site will also serve as my build log as I complete my build process. I will post pictures here, but part of the fun of Cycle Karting is creating something unique for yourself, so I may post sketches and some parts lists, but I will not post plans.

Comments (20)

  • #1 by CycleKart.nl at August 17th, 2009

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    Hi there fellow CycleKart enthusiast!
    Love your site and I will follow your progress on your build.
    I’ll start building my own vintage kart as soon as I have found a shed. In the mean time, please check my website which is still a work in progress but will grow in time.
    I’ve included your RSS in my blog and hope you like it.
    Wish you all the fun in the world!
    best regards from The Netherlands.

  • #2 by admin at August 19th, 2009

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    Your site looks great as well and it is good to see Cycle Karting has such good representation in The Netherlands. The Jap V8 you posted is absolutely fantastic! Stay in touch.

  • #3 by Virgil M. Exner, Jr. at July 29th, 2010

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    I have been designing cars for 70 years including Studebakers, Fords, and (Fiats, Renaults, Volvos, the Selena II, etc. for Ghia). I have loved pedal cars, soapboxes, all racing and sports cars. I also raced a Bugatti in the 60s and have built racing and sports cars.

    I have been enamored with your Cyclekarts for the past 4 years and am laying out both a W 125 Merc and a Novi.

    How may I e-mail my designs to someone who can give me a crit on my design work so far? Can you give me an exact e-mail address?

    Thank you,

    Virgil M. Exner, Jr.

  • #4 by Clay at May 10th, 2011

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    G’day from Australia! I’ve been looking at building a cyclekart for a few years too and have finally started on mine. I love the European GP racers of the late thirties and have designed something that fits the period – a little bit of inspiration from Alfa, Mercedes, Auto Union and even the ERA E-Type.

    Great website, love the updates.

    Cheers

  • #5 by Phil at July 18th, 2011

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    G’day also from Australia- Sydney.

    I too am building a cycleKart- styling undecided. Still designing on paper but leaning towards a later 30’s style grand prix car.
    curves with a aero theme- also Alfa, mercedes influenced.

    Basically what a Alfa/Merc hybrid would have been.

    Mine will have a twist though-

    Full chassis of steel in skeleton style with hand formed aluminum panels. As they were built in full scale as one off or low run builds by the italian coachbuilders.

    I already have the steel to be used, and have weighed the total expected steel to be used at 18kg, allowing for welds and such lets say 20kg / 44lb.
    Thats includes all expected steel needed in
    50mm x 25mm x 1.5mm high strength steel frame rails with bracing at front and rear/enIgine mounts.

    5mm steel rod and 10mm x 2mm flat bar to form the skeleton for the alloy panels.

    Add steel for the front and rear axles, steering etc I estimate 3kg

    The body will be a combination of 0.7mm mostly and some 1mm Alluminum.

    All panels will be riveted together and joined to the chassis, with exception of bonnet and rear engine/tail cover- these will be removable- probably hinged or quick lock fastners.

    I expect my body and chassis to come in under 35 kg ready to add engine and wheels. My goal is a lighter and stronger
    than the trad plywood/steel/glass/foam ideas.
    engine is undecided as I really would like a bit more poke to match the looks.

    A gearbox would be nice as well.

    Having a need for a clutch and gearing for a industrial engine adds cost and weight……….

    Honda ct110 have a light motor with all needed bits- clutch and a 4 speed box…………

    I understand not strictly in the *rules* but would not be overpowered and I doubt I will ever see another cyclekart to race near me.

    Just seems a better solution for me.

    What do people think?

  • #6 by Josh at July 18th, 2011

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    Welcome to CycleKarting.com Phil! I like your concept and have even seen someone build a similar steel/aluminum Cycle Kart. Please keep us posted as you progress, especially concerning your final weight. I am using an unsanctioned engine size for a little extra “poke”, so I’d say give the ct110 a try, especially if you have one handy.
    Cheers.

  • #7 by Phil at July 19th, 2011

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    Thanks Josh.

    Have also spent some time looking at the best way to package the rear end and keep the style needed. The postie motors are all of 7.5hp and not a lot of torque but interesting. Replica motors with up to 20hp are available so that would help with more grunt.

    Basically all the bike style engines need to be in front of the axle for correct rotation or flipped 180 degrees but then most would have oil starvation issues.

    I have looked at scooter engines 150cc- also good but quite long overall. They have a low profile but length becomes the major issue. It would work for a design that has a axle right at the rear but that doesn’t suit what I want.

    So drop that idea.

    Next solution is A real bike engine.

    The copies of 250cc bike motors with a gearbox are real interesting with lots of advantages for a front of axle position.

    Very compact
    4 stroke ohc
    water or oil cooled
    20 hp and lots of torque
    4 or 5 speed gearbox
    light weight- approx 35kg total
    electric start
    much better build than a stationary engine
    no extras such as a clutch or cvt to add /modify
    all of weight is forward of the axle- so mid/rear engined
    Many are available with 4 speeds and reverse!
    Reverse would be very cool.
    Much better sound that suits the era with a megaphone style pipe.
    Only $700 as a complete ready to run.
    Only sprocket and chain needed for drive.
    Proper pressurized oil system.
    Wieght is similar to a postie or stationary engine when installed.
    No need for engine to stick out of bodywork at rear.

    Check out fleabay under zongshen 250cc for pics
    http://www.ebay.com.au/itm/zongshen-250cc-manual-engine-electric-start-quad-/310331506100?pt=AU_Motorcycle_Parts_Accessories&hash=item484132fdb4

    also available as water cooled and versions with a reverse.

    Just mind mapping but this seems a good way to go

    Naturally this huge power would need some serious brakes-
    Just some cheap chinese hydraulic discs on front and rear would be fine.

    Just some thoughts

    Phil

  • #8 by Phil at July 19th, 2011

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    Also the advantage of real engine braking too allow a quick downchange and powerslide out of corners- much more in keeping with the live axle and steering with the throttle.

    Gearing changes are real easy- just change a sprocket.

    The engine design would also allow placement down low in the chassis for better packaging.

    Definately not a sanctioned motor combo but make soo much sense for a more serious cyclekart- performance would be similar to a cheap 250cc bike- so still not really overpowered.
    Cost still meets the philosphy.

  • #9 by Phil at July 19th, 2011

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    does anybody have a weight estimate for a trad Cyclekart frame built from wood/metal/spitballs etc as a complete rolling chassis minus wheels?

    Thanks

  • #10 by Josh at July 19th, 2011

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    I haven’t finished mine to know the weight. Spec, of course, says less than 250 lbs.

  • #11 by Josh at July 19th, 2011

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    Engine cc versus hp is all relative as weight and gearing changes. It would be interesting to see how a Cycle Kart would perform with a full gearbox. Have you visited the yahoo Cycle Kart group (my apologies if you are an active member), at http://autos.groups.yahoo.com/group/cyclekart/. That is definitely the most active Cycle Kart community on the web right now.

  • #12 by Phil at July 19th, 2011

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    Always a worry keeping too tight to the specs as many of the carts built as over it.

    I can only think that the ply box has to be heavy, compared to light steel- even lightened like yours (good idea ). Especially after extra added weight to form shape for a car.

    Going wild with tube and section chassis of alluminium and alloy panels would also be a alternate build option with more weight saving potential.

    I would really like to meet or beat the 250lb target weight even with the heavy bike engine. But given the project, I won’t worry if weight gain creeps a bit to build want I want.

    Given the motor comes from a light trail bike of 115-130kg or 250-280 lbs then anything close to this figure would be great given it is now a car.

    Maybe my version of a cyclekart should be a sportsmen model with allowable changes and weight increase for engine swaps?

    Do you have any idea on the weight of a wheel and tyre?

    Phil

  • #13 by Phil at July 19th, 2011

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    I will join so i can check it out.

    I figured yahoo would be good but hate joining stuff.

    Thanks

  • #14 by Josh at July 19th, 2011

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    Lots of great stuff happening in the yahoo group, as well as some good inspiration. I’ll weigh my wheels sometime and will let you know.

  • #15 by george at August 19th, 2011

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    just finished, well almost, my first car. i based it on a ’36 maserati 6cm and took to focusing on the art over the performance. what a great hobby. last week we had our first race weekend. looks like my winter will be filled with the joy of working on this and starting the next.

  • #16 by Josh at August 22nd, 2011

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    Congrats George! Does first race indicate there are others with Cycle Karts in your area?

  • #17 by Dewey Bond at September 5th, 2011

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    I find these cars VERY cool!
    Where can I buy a complete kit, body, frame, tires & rims, etc.?
    are there any sanctioned races in the U.S.?
    Sure looks like a lot of fun at a reasonable investment

  • #18 by Josh at September 6th, 2011

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    There are no complete kits. Part of the fun is sourcing the parts and making something unique, plus the spec frowns on anyone using anything that resembles a kit. There are no sanctioned races or events. We still need more people to build or finish their cycle karts so more events can happen.

  • #19 by Ben at October 24th, 2011

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    I have thought a lot about cyclekart design and the opportunity this affords “out of the box” thinking and innovation. With this in mind, and the fact that there are no sanctioned events or a sanctioning body, I have leaned more toward the “one off” build which adheres to no set rules or componentry while still keeping the vintage styling and motoring appeal.
    So, being just in the design and parts gathering portion of the project, I have decided to pursue sort of a “recyclekart” concept.
    My chassis will be made from an aluminum ladder. I will use a 5′ step ladder but a section of a straight ladder will do. These are readily available at ant recycling center. Just make sure you have them set one aside for you as they tend to be cut up into small peices rather quickly.
    I have an OHC Honda motor laying around but agree that a 250cc fourstroke motorcycle engine would be the best. The rear axle could then be sourced from any three wheeled ATV or quad which will have an appropriate sprocket carrier and usually a brake disc carrier and caliper mount as well. The axle ends can be lathed out to the correct diameter for the CR wheels and a pinned flange welded on that will mate to the brake rotor flange which is integral to the wheel hub. This would in effect be a pin drive setup with four pins which will slip through the rotor screw holes which would be bored out if wanted.
    The wheels will be from either Honda CR80s or similar dirtbike. They are 17″ and very light compared to the CT steel wheels not to mention much stronger. Tires for the 17s such as IRCs or are very inexpensive as well.

    Body of plywood, fiberglass or aluminum – whatever you want.

  • #20 by Russell at June 9th, 2013

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    Did Phil ever finish his cyclekart? I live in Melbourne and would like to hear from him.