Monkey King's swift Evolution

BY BARRY LICHTER

Monkey King could be getting an advantage of one to two seconds over a mile using his American speed cart, says the man who designed and built it.

And American Tom Harmer has some revealing advice on what many of our drivers are doing wrong, and an answer to an age-old poser on whether overweight drivers slow down horses.

Harmer undertook 200 hours of testing before coming up with the latest version of his Evolution racing bike, and says he has sold more than 1000 of them in the last six years to horsemen in North America, where they have changed the racing style and helped break countless records.

Harmer, who drove more than 4000 winners in his career on the track, says computer testing of the drag generated by sulkies at racing speed showed his bike outperformed nine others by a minimum of 6.3 lengths, which equated to almost 1.5 seconds.

The performance of his sulky was even 3.5 seconds better over a mile than one other in tests where a sulky was hooked up to a vehicle equipped with a computer and load cell and driven at 32mph (51.5km/h) round a half-mile track.

Harmer attributes the improved performance of his sulky to better balance (one-third), better wheels (one-third), more rigidity (one-quarter) and better aerodynamics. Made of aircraft steel alloy, it is heavier than traditional sulkies.

On his website, Harmer says 90-95% of bikes used on the A-grade tracks in North America are his Evolution design.

He claims:

The design promotes better tracking in the turns by reducing the bike's centrifugal force.

The rigid arch provides superior driver support while eliminating frame deformity at race speeds.

The aerodynamic frame minimises wind drag.

The five-star wheel system absorbs shock and provides maximum tracking and stability under all types of race conditions and surfaces.

Harmer says his testing revealed exactly what tyre pressure was optimal for the bike and that performance was also dependent on how high the shafts were hooked.

But his experiments also revealed how drivers could exact the most benefit from the sulky: by rolling along at speed.

"If you have two guys in the same race using my bike, the one who goes to the front or parks, and lets the horse float along, will get the full advantage.

"The one who backs him up is giving up most of the benefit. By taking hold of the horse and not letting the bike roll freely you're not letting it do what it's designed for.

"Up here it's made for more active racing, instead of a spurt out at the beginning and a spurt at the end, and it's seen a lot of records broken."

Harmer says it was during some tests to discover whether heavier drivers were a hindrance that he unwittingly discovered that drivers who rock and throw their bodies around in the cart with extravagant whipping styles are misguided.

"I'd always thought fat guys made for bad drivers but I'm 185 pounds and when I went round at 32 miles an hour my bike registered 19 pounds of drag.

"When I put 50 pounds of grain on my lap it still averaged 19 pounds of drag. I thought that couldn't be right.

"When I put another 50 pounds on my lap, which made 285 pounds on the sulky, it was still only 19.5 pounds of drag. I couldn't believe it."

Most revealing, however, was what happened to the drag when Harmer took his arm back and launched his weight forward, as if to whip the horse. The drag reading shot up from 19.5 pounds to 36 pounds, and was repeated every time he pretended to urge on his horse.

"I won 4000 to 5000 races in the sulky and I never put two and two together. Every time the driver moves he's drawing energy from his horse."

Harmer realises drivers are sometimes forced to wake up sluggish horses, but he still believes a conservative whip action, with very little movement, will produce the best results.

The drivers who rock back and forward and move around a lot in the cart might think they're helping their horse, but the results showed they were actually doing the opposite.

"They might think they're pushing forward on the horse but every time they are also pulling back, and every time their weight is being shaken around and moved they're creating more drag; you couldn't blame the horse for turning around and saying `will you stop that'."

Harmer issues instructions when he sells his cart: the quieter you sit, the better it goes.

- © Fairfax NZ News