Bingo, I re-read my email and when I said it goes up significantly above 45, I omitted the fact (that you allude to) is that it goes up as the cube of velocity. A huge factor. Bob
On Sat, May 15, 2021 at 9:47 PM paul dove via EV <ev@lists.evdl.org> wrote: > > None of that changes physics. You can lower the impact by aerodynamics but > it still goes up proportional to speed and yes they aren't linear. the faster > you go the faster the drag increases. Rolling resistance goes up as well but > it is linear. I did a calculation for my conversion and the areo loading > caught rolling at around 70mph with a dramatic change in the curve around 45 > mph. It was a Toyota Celica so pretty good aerodynamics. I have the spread > sheet somewhere if anyone is interested. It required about 21Kw at 70 mph. > > On Friday, May 14, 2021, 4:56:48 AM CDT, Paul Compton via EV > <ev@lists.evdl.org> wrote: > > On Fri, 14 May 2021 at 03:28, Robert Bruninga via EV <ev@lists.evdl.org> > wrote: > > > Wind drag only becomes significant beginning at about 45 MPH > > Tell that to a cyclist. > > This was something that automotive designers used to say years ago and > what they meant was... > > We have so much engine power available, that aerodynamic drag isn't > affecting vehicle performance until you exceed 45mph. > They weren't much concerned with fuel economy. > > Motorcycles have truly horrible aerodynamics,but some attempts at > improvement have been made over the years. The Royal Enfield > Dreamliner was one example and as well as top speed and economy, it > actually improved acceleration, despite a 40 or so pound weight > penalty. > > https://www.oldbikemart.co.uk/the-dreamliner-lives-on/ > > -- > Paul Compton > www.paulcompton.co.uk (YouTube channel) > _______________________________________________ > Address messages to ev@lists.evdl.org > No other addresses in TO and CC fields > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > ARCHIVE: http://www.evdl.org/archive/ > LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20210515/cb927695/attachment.html> > -------------- next part -------------- > A non-text attachment was scrubbed... > Name: aero-rolling.PNG > Type: image/png > Size: 33035 bytes > Desc: not available > URL: > <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20210515/cb927695/attachment.png> > _______________________________________________ > Address messages to ev@lists.evdl.org > No other addresses in TO and CC fields > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > ARCHIVE: http://www.evdl.org/archive/ > LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org _______________________________________________ Address messages to ev@lists.evdl.org No other addresses in TO and CC fields UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/ LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org
