Physique Rocket, a startup chargeable for producing drag measurement techniques for time trial and triathlon bikes, has launched particulars of a prototype, street bike-compatible system designed to assist its sponsored athletes on the Olympic triathlon in Paris.
The sensor array, consisting of power (energy), air strain, wind pace, acceleration, inclination, and weight, has beforehand been reserved for these bikes designed to race in opposition to the clock, or in non-draft occasions. Even amongst these bikes, the sensors can solely be fitted to a handful of fashions.
Why the swap to street bikes? It seems it was at all times on the playing cards for the model, but it surely has been working intently with Ironman world champion Kristian Blummenfelt, who has not been focussing on street bike, draft authorized triathlons. Now, within the build-up to the Olympics, the place he’s trying to take the gold medal, it’s hoped that the setup fitted to his Large Propel effectively prematurely will give him a aggressive edge, and time to optimise his place and setup.
How does it work?
Aero testing primarily takes place in a wind tunnel. Parameters are tightly managed, however generally wind tunnel time is a fraction of the time spent coaching. The Physique Rocket system goals to duplicate the info produced in wind tunnel testing however in the true world.
To realize this the street bike has been fitted with a brand new, up to date airspeed sensor which mounts beneath an out-front laptop, resembling the nostril cone of an plane or the bulbous bow of a cargo ship.
Behind this can be a custom-made stem, containing all of the sensors beforehand housed in a separate standalone unit that often resides on the base of TT bar extensions.
On the prime of the built-in seat mast is an extra sensor, working in tandem with the stem to measure rider weight; as this could fluctuate all through a race resulting from hydration ranges and sweat it’s essential to measure fairly than estimate this it appears.
Lastly, a pair of pedal sensors add to the drag equation and all of this feeds again right into a bottle cage-mounted relay unit, which in flip transmits the real-time CdA knowledge to a Garmin head unit.
With out going into the total coefficient of drag equation it is onerous to totally perceive what every sensor does, however in response to Physique Rocket Founder, Eric DeGolier, “Every sensor measures horizontal and vertical forces, and the saddle and handlebar sensors additionally measure pitching and rolling moments, permitting the system to not solely measure drag forces (the sum of the horizontal forces at every sensor) but additionally observe the rider’s place on the bike.”
It’s unclear presently how a lot of an aero penalty these further sensors add.
How correct is it?
Realtime measurement of drag is definitely of profit to skilled athletes, although except it’s correct it might be of no use. The system, fitted to a BMC time trial bike, was examined alongside a wind tunnel by making equivalent setup adjustments.
The model’s knowledge reveals a most deviation from the wind tunnel of two.7% and a mean variation of 0.7%. Whereas this was arrange on a time trial bike it does point out that, offered the system is successfully the identical, it does provide real real-world aero testing alternatives that may rival a wind tunnel.
