C
Clive George
Guest
"Andre Jute" <[email protected]> wrote in message
news:[email protected]...
>You have to set the truck up right or you can take a nasty spill if
>you release directly into the over-the-kamm eddying. The best sort of
>truck is a refrigerated truck, among other reasons because its weight
>causes smooth transitions in motion. The rear doors are opened at 45
>degrees or more, depending on the width of the road, and stayed with
>rods attached to the lock mechanisms with ratcheting pipe clamps. The
>space at the bottom across the back and below the doors is filled in
>with 19mm ply; you need three 8x4ft sheets. When the truck accelerates
>after releasing you, and you slow anyway because the grade isn't steep
>enough for the speed, the width of the aero envelope puts your
>exposure to the buffeting further back where it is already much
>weaker. I know quite a bit about airflow over and behind fast cars
>(I'm the author of a book on designing and building prototype and one-
>off cars), and this problem is another reason I didn't even think of
>trying for the 100mph rather than the 100kph.
TBH going for 100kph with mechanical assistance isn't really pushing
things - that sort of speed is achievable on your own, given a suitable
hill. Having something slightly more aerodynamic than your gazelle will help
(which isn't exactly hard), and choosing the right day for the tailwind.
Tandems are very good for this - more weight for the frontal area, and dead
stable at speed. Or a suitably faired recumbent. And yes, I've done it. No
trucks, plywood, road closures, etc, just two of us, one bike, and the
corner with the water flowing over it coming up
reallyveryquicklytimetobrakeHARD.
FWIW the road near Cambridge mentioned before was well-enough surfaced.
clive
news:[email protected]...
>You have to set the truck up right or you can take a nasty spill if
>you release directly into the over-the-kamm eddying. The best sort of
>truck is a refrigerated truck, among other reasons because its weight
>causes smooth transitions in motion. The rear doors are opened at 45
>degrees or more, depending on the width of the road, and stayed with
>rods attached to the lock mechanisms with ratcheting pipe clamps. The
>space at the bottom across the back and below the doors is filled in
>with 19mm ply; you need three 8x4ft sheets. When the truck accelerates
>after releasing you, and you slow anyway because the grade isn't steep
>enough for the speed, the width of the aero envelope puts your
>exposure to the buffeting further back where it is already much
>weaker. I know quite a bit about airflow over and behind fast cars
>(I'm the author of a book on designing and building prototype and one-
>off cars), and this problem is another reason I didn't even think of
>trying for the 100mph rather than the 100kph.
TBH going for 100kph with mechanical assistance isn't really pushing
things - that sort of speed is achievable on your own, given a suitable
hill. Having something slightly more aerodynamic than your gazelle will help
(which isn't exactly hard), and choosing the right day for the tailwind.
Tandems are very good for this - more weight for the frontal area, and dead
stable at speed. Or a suitably faired recumbent. And yes, I've done it. No
trucks, plywood, road closures, etc, just two of us, one bike, and the
corner with the water flowing over it coming up
reallyveryquicklytimetobrakeHARD.
FWIW the road near Cambridge mentioned before was well-enough surfaced.
clive