Introduction

While attending the 2024 Huntsville Grand Prix earlier this year I had the opportunity to speak with Mark Parnell from Renegade Cyclekarts.  As he was showing me the current build of his amazing and crazy Hannibal 8 car from the movie The Great Race, he commented how he wanted a two seat cyclekart so he could take others on rides.  I too felt the same way about sharing rides and more actively promoting this sport in a more personal and meaningful way.  

Mark’s comment struck a chord with me and that evening I began searching for a two seat car in the Edwardian Era.  In a very short time, I found this beautiful 1910 Pullman and was immediately smitten.   Fortunately, there were many excellent photographs of this car which will really help designing a cyclekart with similar features.  These old cars from the early automobile era are so mechanical, beautiful, and mysterious all at the same time. And just like that, my mind was made up, a 1910 Pullman two-seater-cyclekart it would be.

Specifications

Pullman Model O Roadster 1910 had a 40 horsepower 25.3 cubic in T- head in line 4 cylinder engine with a three-speed manual transmission.  It incorporated a solid front axle and a rear axle with semi-elliptical leaf springs and two-wheel mechanical drum brakes.  The wheelbase is 108 inches.

History

The launch of the Pullman motor car in 1905 was well received and by the next year its manufacturer the York Motor Company company of York Pennsylvania offered four models of 4 cylinder cars priced from $1,850 to $2,500.  The future looked promising but after the Panic of 1907 the company fell on hard times and additional capital was required.  Two New York financiers, Thomas O’Connor and Oscar Stevenson responded.  They did not; however, get along with company president Samuel Bailey or general manager James Klein.  Klein left and soon Bailey followed forming a new company in New York that would build the Klein car company.  O’Connor and Stevenson then reorganized the York Motorcar Company into the Pullman Motorcar Company

There were some great successes including a win in the 1910 Fairmount Park race in Philadelphia and three gold medals at the 1911 Russian Exposition at Rosta Von Don in southern Russia; however, success sometimes hinders caution and in the effort to boost production some corners were cut and sales suffered.

Capital investment from a syndicate of local businessman headed by John Schmidt arrived late in 1915.  Engineers from White and Cleveland enlisted to design a lower price line model but it was all for nothing as the company filed bankruptcy in December 1916.  There were over two thousand Pullman cars manufactured but only a small handful are believed to still exist today.

Project Timeframe

My first Bugatti Type 13 cyclekart project was an incredible journey of learning and I feel compelled to extend my journey to the next level with the 1910 Pullman Roadster project.  I love learning and this project demands another level of construction that has me very excited.  While I am all too eager to build this new cyclekart for the 2025 Huntsville Grand Prix race in early May, I realize that it conflicts with my lofty design goals.  I have therefore decided to not make any compromises in my pursuit of my more ambitious undertaking so I will dedicate whatever time is required to build this to the very best of my abilities and budget. In the meanwhile, I still have my Bugatti Type 13 to drive around which keeps my cyclekart juices flowing just fine.

Project Design Concepts

Front Mounted Engine
I’ve wanted to build a car with the engine up front for a long time.  So this will be the perfect project for that.   I plan on using a standard 6.5 HP Predator engine with stronger valve springs, removed governor, and an electric motor start.  I’ll still have a fake motor crank up front.

Anti-Vibration Motor Mount
These cyclekarts are such rattlers, in no time at all another part seems to be falling off or gone missing.  So I will devise some sort of anti-vibration mounting to isolate the engine from  the frame.

Drive Shaft/Gear Box
Not liking the idea of a long chain drive between the front mounted engine and the back wheels, I’ve chosen to employ a driveshaft and rear gearbox.  Colin Warnes came up with a design that I will copy.  While it will make the cyclekart heavier, my main motivation is not striving for speed, so I’m OK with the added weight penalty.  Colin’s design appears to work, and he provided enough design detail that I should be able to replicate the parts I need.  I will depart from his design where he employs externally exposed gears to drive his wheels; mine will follow the more traditional gear setup with them located near the midpoint along the axle.

Front Axle and Spindles
On this project, I will build my own axle and spindles.  I’ve done a lot of research on the design and components and believe my welding, while not the prettiest, will be more than strong enough.  I am considering moving up to a TIG welder, but that may not be within the time frame or monetary budget constraints.  Besides, I told my wife that last years purchase of my Titanoim MIG welder would be good for many builds in the future.

Rear Axle
I am teetering on whether to use a solid axle or a Peerless differential axle.  I already own a Peerless differential axle, so I’m tempted to head in that direction.  But I need a much longer axle so my existing Peerless setup will not work.  Based on my current design, the rear axle will be 52″ long. 

Rear Wheel Suspension
The rear suspension on the 1910 Pullman used quarter elliptic leaf springs to carry the axle, cantilevered from the rear of the chassis.  To accommodate the fluctuating axle, I will build a swing arm hinged midpoint along the frame that carries the rear gearbox and axle.  The swing arm will be connected to a rear quarter elliptical springs for suspension.  Steve Vinson did a nice swing arm design that I plan on following.

Wheels
I am using the fake wood spoke wheel in the form of an aluminum mag wheel that comes out of China.  This is an 18 inch wheel which is being promoted within the cyclekart community for the Edwardian era motor cars.  They require the bearings be replaced and also require a longer rear axle.  The wheel track will be 50″ to better accommodate two passengers.  So this track width falls way outside of the vintage race car rules, but again, this car is not meant for racing.  These aluminum mag rims are also heavier weighing in at 8 lbs vs 6.6 lb for the standard Honda 90 type. 

Brass Parts
Automobiles from this era had lots of brass components that really helped to establish their unique look.  Brass is super expensive, so I will investigate all the brass colored paints and use that in lieu of real brass. The brass paint I used on my Bugatti was OK, but I want to look for something better.

Acetylene & Kerosene Lamps

The old kerosene and acetylene lamps commonly used for lighting will be replicated to the best of my ability.  I will not use the gas or kerosene, but will employ modern day low-voltage LED or incandescent bulbs.

Onshape Design
I have moved over to Onshape to conceptualize this design.  My original occupation back in 1978 was design drafting, so I am employing the same elementary techniques with this modern marvel of engineering.  

My design process only considers the overall layout and dimensions of the cyclekart with the three views, side, top and front.  One huge advantage Onshape provides me over my old style drafting is it allows me to draw over an imported picture that I scale to fit my parameters.  That ensures I have the right overall size, shape and appropriate placement of the major components. 

Once the chassis is built, I will then proceed to the engine mounting and body framing.  All other details get figured out on the fly as I go or as I lie down at night before falling asleep.  I truly admire the more advanced designers who take their designs to a full 3D rendition whereby they figure out the loads, assemblies, parts movements, interferences, etc.  Maybe I’ll reach that expertise someday, but my old ways blended with this new tool work perfectly for me.

Weight Problem
I’m talking about the car here, not me!  Please focus!
With the heavier spoked wheels (+5.6 lbs – not including tires), front-mounted engine, drive shaft, gearbox, added sprockets, swing arm structure, battery, generator, canopy, wooden trunk box, extra large lights, acetylene generator, luxurious two-seat bench, longer and wider frame, etc., etc., this car is quickly going to become a very, very heavy beast.  My Bugatti was heavy enough at 325 lb when most are closer to 275 lb.  I’ll be lucky to keep it under 500 lb and with two 200 lb passengers, we’ll be trying to move 900 lbs!  Compared to your optimum 225 lb cyclekart and 165 lb driver for a total of 395 lb.  So this little engine needs to push over twice the optimum weight.  There’s no doubt the engine will do it; I just need to ensure the gearing is low enough to allow it to begin rolling forward.  I’ll sacrifice top-end speed, but I’m not trying to go fast.  

Nevertheless, weight is going to be a severe issue.  Possible solutions include:

1.  Go with a lighter frame than 1″ x 3″ steel.  1″ x 2″ weighs nearly 1 lb. less per foot.  There will probably be close to 30 ft in the frame so that’s an easy 30lb savings which is pretty huge.
2.  Forego the front-mounted engine, drive train, gear box, and added sprockets
3. Use a lot of carbon fiber rather than steel or aluminum where ever possible
4. Make the entire bench seat out of carbon fiber
5. Step up the motor size to the Predator 15.8 HP (459 cc) engine
6. Use a Ghost racing engine, still 212 cc but closer to 15 HP.