I thought I'd add a bit of clarification based on my understanding of substituting a bit of aero drag for a bit more of rolling resistance:
>From my customer: "Speeds over 8-10mph create substantial lift, effectively reducing rolling resistance from heavy loads. The effective reduced rolling resistance is significantly greater than the increase in drag from the wings, allowing net increased speeds as compared without the wings, given with the same applied peddle pressure. We tested various wing-load weight combinations using an actual Xtracyle setup (attached to a 1984 Specialized Stumpjumper) with weight-loaded freeradicals at full-scale. At 4mps (9 mph), the 8-foot wings with 150 of loaded weight allowed for a net lift/drag factor of 1.34, effectively overcoming the weight-increased rolling resistance. Our research was conducted using the Low Speed Wind Tunnel at the Laboratory of Aerodynamics at Helsinki University of Technology, in March, 2005. The results of our research can be found at: http://www.aeronautics.hut.fi/edu/malli/Malli_aero.htm. Once our research is published, if there is ant interest, I'll post photos of the Extracyle under various wind tunnel test conditions. In the meantime, here's an image of the testing facility: http://www.aero.hut.fi/Englanniksi/index.html Note that some caution is warranted at speeds approaching 14 mps (31 mph), due to available lift, resulting in a what we've termed the "E.T. Effect" whereby the entire vehicle can become airborne." -- Kipchoge Spencer Xtracycle 29085 Highway 49 North San Juan CA 95960 530/292-1401 www.xtracycle.com RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
