tag:blogger.com,1999:blog-13887692.post6800560441651781947..comments2024-03-13T02:16:08.135-04:00Comments on Cozy Beehive: Dynamic Stability Of Bicycle Design : Part 3Ron Georgehttp://www.blogger.com/profile/18394865788996482667noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-13887692.post-19191417701753023202009-09-24T21:06:06.443-04:002009-09-24T21:06:06.443-04:00The fork is mounted backwards to increase trail on...The fork is mounted backwards to increase trail on the test bicycle.Jason Moorehttps://www.blogger.com/profile/15362357639624306439noreply@blogger.comtag:blogger.com,1999:blog-13887692.post-67026855745420784652009-09-22T23:33:54.324-04:002009-09-22T23:33:54.324-04:00Mark : Thanks for reading. You're hoping somet...Mark : Thanks for reading. You're hoping something I guess we're all hoping for pretty soon - a unifying equation of motion for a closed loop system that takes into account all the parameters actually seen in real life. Today we have more of rough, final verification that is very subjective and not enough analysis done from a dynamics standpoint.Unknownhttps://www.blogger.com/profile/12256394060474969622noreply@blogger.comtag:blogger.com,1999:blog-13887692.post-74735133871760256672009-09-22T15:49:49.393-04:002009-09-22T15:49:49.393-04:00Why is the fork on the riderless bike in the video...Why is the fork on the riderless bike in the video mounted backwards? Was this a deliberate move to create a bike with lots of trail?jim ghttps://www.blogger.com/profile/02161517903295268167noreply@blogger.comtag:blogger.com,1999:blog-13887692.post-15302717864610491212009-09-19T08:18:35.376-04:002009-09-19T08:18:35.376-04:00Again great pollination Ron !
Fascinating comment...Again great pollination Ron !<br /><br />Fascinating comments above from (THE) Jim Papadopoulos. Which chime with my own testing (on adjustable geometry bikes, real roads and most important, a variety of people). The human ability to learn and adapt is not to be underestimated. Likewise apart from geometry, riding position, CofG, the person's weight distribution and muscle tone, all along with stuff like stem length, height and bar width.<br /><br />I would love to have a unifying set of equations, which work for all variables and am fascinated by all these wonderful attempts. These would help with then often un scientific (some would say BS) seen in some magazines about bike A handling characteristics vs Bike B. However I still think testing with a variety of differently experienced riders with still be needed , if only for final verification.Human_Amphttp://www.mas-design.comnoreply@blogger.comtag:blogger.com,1999:blog-13887692.post-73581795984237284822009-09-18T20:32:25.214-04:002009-09-18T20:32:25.214-04:00Hi, this is Jim Papadopoulos, whom you kindly cite...Hi, this is Jim Papadopoulos, whom you kindly cite in your post.<br /><br />I haven't studied what you wrote in detail [apologies, I'm frantic with various obligations] but it looks like a very nice and accurate description of our work. Congratulations for 'getting it', and presenting it so nicely. <br /><br />But that said, I want to talk a little about the limitations. JBike6 is all about inherent stability, and the model is clearly a little unrealistic -- no hands, a perfectly rigid rider, and none of the nasty frictional properties of tires. I don't want to say the modeling is wrong, but there remain some questions to be answered before interpreting the results in terms of rideability. Actually, the equations were validated quite well [by Kooijman and Schwab] for a riderless bike, which also meant the tires were not compressed much [so they had a short contact patch and could possibly act more like ideal rigid wheels].<br /><br />In terms of ridden bikes, I surmise that JBike6 might apply best to recumbents (where the rider is secured to a seat) with extremely hard tires, ridden no-hands of course.<br /><br />My personal view, with which Schwab and others may not fully agree, is that true bicycling by a human involves (a) the pressure and mass of the lower arms attached to the handlebars (b) the rider being free to tilt and rotate at the waist, where a system of muscles and sensors are used to keep the rider more or less lined up with the frame (c) the aforementioned tires (d) a control strategy for adjusting bicycle+rider lean for balancing and turning (e) a control strategy for making quick maneuvers or recoveries. <br /><br />If I am right about this, substantial work needs to be done to expand the model, and then to understand and embody strategies for sensing and muscular activation [in both the waist and the arms]. In other words, a long way to go to understand riding (stabilizing and controlling) qualities, as opposed to riderless stability.<br /><br />Keep up the good work!Unknownhttps://www.blogger.com/profile/05325066825429314530noreply@blogger.comtag:blogger.com,1999:blog-13887692.post-49035247116271788462009-09-18T12:35:39.174-04:002009-09-18T12:35:39.174-04:00Very cool area of research and thanks for your tir...Very cool area of research and thanks for your tireless working in educating. I confess I lost touch with blog posts for I had a hectic week but I think I have some time today to play catchup. :)Philnoreply@blogger.com