What does it feel like to race a Stealth Fighter on a GoKart track?

In one word? AWESOME!

One of the great aspects of the 2014 Hunter Electric Vehicle Festival is the commitment to parameters for different racing classes so there are common benchmarks for power output to retain a level of competitiveness, an important aspect in Electric Bike racing. In the 1500 class, bikes are limited by battery capacity to 1500Watt Hours (1.5kWh) as the main constraint, with some other racing class regulations. The race takes a similar approach for defining power capacity limits for the High School classes, which keeps the racing competitive and focussed on efficient performance to squeeze the most out of a 384Wh battery. 

The Stealth Fighter, with a 3500W motor and weighing in at 34kg, fitted with a set of street tyres like Schwalbe Crazy Bobs is an easy choice for this racing class. Whilst working below class capacity for the battery, Stealth have made sure the power is delivered efficiently for effective range as an off-road electric bike and ready-to ride product. With plenty of suspension travel, there's little risk involved if you find yourself drifting off-track. In fact, it almost eggs you on to give it a go, since this is what it's built for.

Highlights
1. Human-scale speed: With a top speed of around 60-65km/h, we find that this is an effective human-scale speed for this racing class, which allows for lower risk in the event of a slide, reduced impact and damage to the rider and bike. With a long history in dirt bike riding and mountain bike racing, we know full well the downside risks when things go wrong. Having a set of compliance rules that encourage solid protection for the riders head plus all major joints+points (hands, elbows, knees, feet) helps add to the safety of the rider. The level of adrenaline and attention required still ensures a high level of cardiac output, which can be seen in the race plot below, so there is some interesting stuff happening physiologically as the riders concentrate on the race;

2. Silence: Aside from the Solar Challenge, we can't think of another powered racing class that is so quiet. As you move at top speed around the track, its possible to engage with other competitors in friendly banter, egging each other on, or passing on observations about smelling overheating motors being pushed to their limits, or simply calling a warning during overtaking. It makes for a very social, yet friendly competitive event. Engine sound effects are optional, left to the inspiration of the rider and their engine style preferences (2stroke or 4? Inline or V?) - other riders just hoot and laugh at the fun they've having;

3. Safety: As a business owner and father of 3 young kids, I can't afford to take the same risks I once did - the consequences are far more dire in terms of life impact than if I were young and single. As a Health Professional working in injury rehabilitation I've seen my fair share of people who think they can take the same risks they used to when younger. The body doesn't bounce back as fast as we might like to think it will, and injures more easily than we might expect (go look up Optimism Bias), which is a consequence worth thinking through before committing to a corner overcooked. With plenty of run-off spaces, a GoKart track makes a great medium for racing, with tight turns preventing high speed and rewarding a skilled rider who picks their lines as a counterpoint to a rider on a faster bike, using the full 1.5kWh capacity.

Strava plot of Speed, HeartRate makes for interesting race analysis.

Conclusions
1500 class electric bike racing reminds us of the now defunct 50cc GrandPrix racing class, with teams extracting maximum power from little engines within a lightweight chassis. Its a similar racing format, but made safer and more acceptable with lower speeds and no noise. When combined with solar charging, it makes for great EcoFriendly racing. Loads of fun, easy on the ear and planet, yet exhilarating, adrenaline inducing and within an acceptable risk margin for human limits of the average rider. For anyone using a Stealth in the class, they can rest easy knowing they can then still turn it to off road action that is every bit as much fun when the racing is done. Now I wonder how it might look if we were allowed to actually pedal?

Edge contact patch for Crazy Bobs on tarmac