To John and co on the forum thread Aero Time Trial Helmet, thanks for your ever thoughtful responses.

As we want the record to be for a production bike, we need to work with what we have on that score, this means aeroising (is that a word?) the carboyoke is out, narrowing and lowering the handlebars, in!

Maria's focus is on her preparation, diet, exersize, training, conditioning, nutrition, maintaining energy throughout the ride. Jim is there also, supporting and attending to the organisation of the attempt, where there is also much to do. Neither Maria or Jim are tinkerers on the bikes, they contribute in these other important ways. I would love to be there swapping handlebars etc, but the reality is I am in Perth, which is about North Carolina longitude + 180 degrees and NC latitude * -1. They are in the direction of my feet, strangely enough!!!!!!!

One of the outcomes of making one Silvio frame size to suit all comers is that some key ergonomics tend to drift at the margins. That is, for shorter folk, the handlebars are quite tall once they are close enough and long leg people have the BB lower than what it would otherwise be. And in the end, I always said Silvio was built to a purpose of providing a great, great ride with excellent efficiency, comfort and plyability on the road and with traffic. The bike that is a true alternative to a road bike.

Time trial records are of course done on time trial bikes, which the Silvio is not. So we have a new faster one in the wings. We might not be able to tamper with the Silvio is search of a record, but we could produce a whole new design - yes a time trial bike rather than a road bike. How would this bike differ?

Our time trial bike takes slightly more liberty with the parameters that influence how the bike rides on the road. Compared to the Silvio, the rider's body is lower, it is more reclined. There is no suspension, the headtube is the same height relative to the seat, but the seat itself is around 4 inches lower, which makes the boom more horizontal and the bars relatively lower. The vertical depth of the frame and bars overall is about 6" less.

You can see from the photograph that below the seat is a vertical web running the length of the seat, with the rear stays mounted from it. At the leading edge of this web the downtube is ridgidly connected to both the seat pan and the web.

Also visible is the concave curve of leading and trailing edges of the web. These show the wheel positions. The web doubles as a splitter plate, heling to smooth airflow under the rider and minimising turbulence behind the rider. The flanges of the seat back serve to initiate lower level turbulence which is intended to avoid a large volume of low pressure air accumulating behind the rider, aiding the left side and right side airflows to join up smoothly behind the rider. The frame is intended to be used in conjunction with disk wheels.

Like the Silvio and unlike any FRP seat found on many lowracers, the seat adds the bare minimum to the rider's depth, perhaps 0.5" or thereabouts.