Aerodynamics / Aerodynamic Cost / Aero parts

Oh cool, I didn't know that.

I guess any performance will be marginal from what they can currently achieve, or is there still ways to go significantly faster, without drafting?

There might be, they just haven't found them yet :)

These are the recent record jumps, so it depends what you consider marginal vs. significant gains:

"On land, the speed record registered by a rider on a 200-meter flying start speed trial was 133.28 km/h (82.82 mph) by the Canadian Sam Whittingham riding the Varna Tempest, a streamliner recumbent bicycle in 2009.[13] at Battle Mountain, Nevada. His record has been surpassed by 0.5 km/h by Sebastiaan Bowier of the Netherlands in 2013 setting the new record of 133.78 km/h (83.13 mph). The record was again surpassed on 19 September 2015 by Todd Reichert by riding the ETA, a streamlined recumbent bicycle at 86.65 mph or 139.45 km/h from the team behind the AeroVelo Atlas human-powered helicopter.[14][15] Todd Reichert broke his own record again on September 17, 2016 to set a speed of 89.58 mph, or 144.17 km/h at the 2016 WHPSC. [12]"

Would be interesting toknow the power output of the various riders during these attempts.

Presumably the majority of the improvements are down to aerodynamic gains, but I wonder how much is attributable to stronger, better trained riders?

I know Ken Buckly had a pop and perhaps got the british record, he certainly seems to boot out plenty of power in a 10 mile TT (420+)

They all have weird 'riding' positions (prone, etc) so I guess it's a bit of a compromise between an super compact aerodynamic shape and what someone can actually put power out in.

Graeme Obree’s attempt (and documentary) are probably well worth a watch for those interested. I reckon he might put out decent power (despite the years).

Ex Track riders might have some fun on the shorter speed trials, imagine Hoy putting down some massive watts.

I imagine most of the speeds are reached in fairly quick time?

http://www.gobattlemountain.com/

I think that getting them up to speed is pretty tricky.

Problem is most trackies are big or at least wider than roadie sprinter types and that's going to hamper your aerodynamics. You've also got to spend a shit load of time developing power in whatever position your vehicle requires.

5mi run up then timed over 200m

https://www.engadget.com/2015/09/18/aerovelo-fastest-human-powered-vehicle/?guccounter=1

Typically you’re encased in a carbon shell? So surely the biggest factor if you’re recumbent is shoulder width, and leg clearance?

So maybe someone more like Caleb Ewan or Coquard might be better suited for less width and volume, assuming they can hold 1000+ watts for a sufficiently long amount of time in the best aero position.

Ewan is basically in a reverse recumbent position as it is when he sprints.

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I think the major upgrade to the latest record Todd Reichert, riding the ETA was that there is no window and the rider uses a camera to see forward and that gave a smaller cda (about .012 m^2):

Edit: the previous record was also a camera bike but it has side windows if the camera fails. I think allowing cameras is a newish addition to the rules.

Yeah, that's what I mean with road sprinters (small guys, lots of power) vs track sprinters (bigger guys, crazy power).

Also the 5mile run up to get up to speed changes the type of rider you need completely, in my mind I was thinking they were after top speed after an insane acceleration.

I guess any performance will be marginal from what they can currently achieve, or is there still ways to go significantly faster, without drafting?

Being drafted can improve a vehicle's aerodynamics.

But isn't allowed in any of these events.

On average for a time trial cyclist your CdA will drop by 3.5% if you've got someone on your wheel.

Of course if you're racing a time trial you shouldn't have someone on your wheel because they've let you go after being passed... (TTTs >>>)

I had some friends out at Battle Mountain last month for the speed trials, there were two British teams - The Soup Dragon, designed by Mike Burrows and Glenn Thompson but it was new and didn’t fare too well, only reached about 58mph and proved too unstable for the rider to risk going any faster. It was fixed gear and very minimalist, theoretically capable of 93mph. The Arion team from Liverpool Uni took both the men’s and women’s hand-powered records with Arion 4, a multi-track machine (a trike with two rear wheels and front wheel drive/steering. There were no outright speed records broken due to conditions (a bit windy) and the fact that reaching 90mph is proving a bit of a hurdle.

The current crop of machines (Burrows’ bike aside) are all quite similar in design now, almost all use a camera for vision but rules state there must be a duplicate system in case of failure. There’s some good footage of the event online.

Interesting round up of Russ’s experience with the SD and just how scary it was...

https://youtu.be/0a7usJV_xDo

Hillingdon?

12 'days' of training?

Russ races recumbents regularly so was a decent choice. I’d have had a go myself if it had been a few years ago, but I quit racing.

Fascinating video.
Twelve days training=five kilos lost, oof.