In the pursuit of speed and performance, is AMCN reader Kent Shillitoe tilting at windmills? Only time attacks will tell…
In the world of motorcycle nuts, there are those who ride, those who race… and then there’s professional tinkerer Kent Shillitoe – a man who has dared to reimagine the very concept of two-wheeled speed. This is the tale of how a daily commute on a humble Honda CBR125R sparked an engineering idea that challenges conventional design and pushes the boundaries of what’s possible on two wheels.
Kent’s journey began with a simple question: What if we could eliminate the need for extreme lean angles in high-speed cornering? One long rabbit hole of innovation later, the seasoned racer and skilled 32-year-old fulltime mechanic from Adelaide has devised a unique tilting wing that combines the agility of a sportsbike with the stability of a three-wheeler.
From backyard welding sessions to dyno-destroying mishaps, Kent describes for us in his own words (gently spurred on by his fiancée, who really just wanted him to get the word out there!) the inspiration, challenges and triumphs behind an unconventional design that might just represent the future of motorcycle time attack racing…
The inspiration
Weaving along a quiet country road one warm November morning on my daily commute to work, I was once again gifted with the clarity of mind and time to think that can only be attained on an a 10hp motorcycle.
Tucked low behind the screen of my Honda CBR125R, throttle set to wide open with no chance of exceeding the speed limit, my mind drifted to the opposite end of the sportsbike spectrum. I wondered… What would a no-rules, completely lap-time-focused motorcycle look like? And actually, why is there no popular time attack racing series for these creations?! Hmmm… Oh well, I guess the shoulder-scraping speeds of MotoGP must already be near the limit of what’s possible on two wheels…
Wait a minute, that might be it! We’ve been bandaiding the side effects of extreme lean angle for years. Maybe lean angle is the elephant in the room holding bikes back? Hmmm indeed…
The plan
Over the next few days my head spun round with all sorts of exotic chassis ideas. Motorcycles are already missiles in a straight line. But how could I turn my little CBR into a high-downforce, two-wheeled version of a Can-Am Spyder?
I found myself drifting off into fantasy land… until the reality of building it kicked in, forcing me to settle on a simple trailing arm steering design I knew was within my backyard manufacturing capabilities.
Learning over the years that no good idea is original, I sat down on Google, searching all the keyword combinations I could think of, trying to uncover someone’s past attempts at my swinging, steering/tilting wing design, but to no avail. Possibly a red flag for failure but to me that was the green light I needed to get started. I was excited by the potential treasures of deeper knowledge I might discover along the way, and also – I have to admit – for the childish fun of coming up with a unique project name!
The build, part 1
I really wish I had access to some sort of fabrication workshop but, unfortunately, I don’t. Which meant relying on my trusty gasless mig welder gifted to me from my Pop, my five-inch angle grinder, and the closing of one eye to align all the pieces. So, when the time came to start chopping into my little CBR I thought it would be wise to source a second frame to butcher instead.
Luckily, the friendly John at Show & Go Motorcycles had one in his possession not too far from where I live.
From that purchase on, after many hours of cutting and welding whenever I found the time, I finally reached the pivotal moment where my creation was rideable.
Wingless, but rideable!
Taking off on the maiden voyage, the sensation of the handlebar moving laterally from the frame was so strange and foreign it generated a sick-to-the-stomach reaction – just like losing the front does. I was worried, thinking all my time had been wasted, but it didn’t take long at all to adapt, and before I knew it I was carving from side to side, smiling from ear to ear, thinking – this might actually work!
The build, part 2
Next up came mounting the wing and the linkage to control its tilting action. The position of the wing was guesstimated by trying to align the approximate centre of pressure slightly forward of half the wheelbase, and also the essential factor of being able to see where I was going! I then drew up a scale diagram to calculate the measurements needed between each linkage point. This was done with the aim of giving the wing just the right amount of tilt angle to keep it horizontal while cornering.
When complete and test ridden it all worked really well, so I made the, in my opinion, “logical” decision to up the ponies. Fitting a Yamaha YZ250 engine I had lying around in pieces quadrupled the power of my little CBR to a still slow but much more respectable output of nearly 50hp!
But, alas, no project is without a setback – and that came for me with the extra vibrations the two-stroke engine introduced. It shattered the coolant overflow bottle and cracked my radiator beyond repair, squirting hot coolant everywhere while tuning on the dyno! (A huge thanks to my boss, Lee Banks at Lee’s Spot On Motorcycles in Mt Pleasant, for the dyno use and tuning wisdom, and an even huger sorry about the mess!)
The riding experience
I’ve ridden a lot of motorcycles at work but nothing compares to riding this thing. It’s like a whole different species. Obviously there’s the weird steering – but also the sound, the smell and the power delivery all combine for a serious assault on the senses.
The modern hanging-off-to-the-inside technique is used but the bike comes with you; it’s a strange feeling to begin with but even now I can’t believe how natural it is once you get used to it.
The combination of downforce at speed, damped lateral front wheel movement and the more vertical suspension angle for bump absorption create a very glued-to-the-road, front-end feeling.
When entering a corner, just a small counter steer/push of the ’bars outward and whoosh, turn initiated. The air rudder design on the trailing arm also contributes to the quick tip-in.
All its qualities feel promising but I do understand that my design is likely to fail when it gets pushed to the limits on a racetrack.
Just like every other alternate front end that has come before it. I’m hoping its saving grace could be in that at least it attempts to solve some real motorcycle flaws, and the swinging motion is a pivotal key to unlocking all sorts of mechanically simple active aero/straight line DRS systems in the future. Speaking of which…
The future
The goal is to take it for a spin on track soon, somewhere like Mallala Motorsport Park or McNamara Park in Mount Gambier, but I’m unsure if I’d even get through scrutineering! I guess, truthfully, the child in me dreams of it showing potential, catching the eye of someone with greater manufacturing capabilities (like a university), and then being involved in the creation of a fully optimised, wind tunnel tested, ride height device and ground effect utilising, lap record destroying, Kejashi motorcycle!
At the moment I know my little prototype is ugly and seems to agitate a few people, but I don’t mind. I had many fun moments creating it, learned a lot of new skills, and uncovered all sorts of knowledge treasures along the way.
Finishing up
I’d just like to say a big thankyou to my fiancée Kelsey for taking photos, making the stickers, creating a YouTube video and forever putting up with my weirdness. This project is definitely a bit out there – but with Ducati’s GP25 development reaching somewhat of a standstill this year, I have an inkling we may just see some Kejashi-inspired elements on the GP26!
WHO IS KENT SHILLITOE?
“I’ve always had a fascination for motorcycles, with many good memories of getting my hands on an AMCN magazine, reading it from front to back, over and over until I’d pretty well memorised it. I’ve been a fulltime motorcycle mechanic since 2008. It was my dream job as a kid, and I’ve always enjoyed tinkering with things. My biggest claim to fame in the industry was winning the 2012 National Motorcycle Mechanic Apprentice of the Year award when the prize was a brand new Honda CB400, donated by the Ulysses club. This photo is from when I went to Phillip Island for the MotoGP last year and got to meet a childhood idol, Jeremy Burgess. I resisted showing him a picture of my project, though, because I didn’t want to take up too much of his time!”
