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Post by trikesrule on Sept 6, 2007 21:42:39 GMT
Hey JR Recently I came across an article where a guy had cut the steering head of his MC and reset the steering head vertically. He and his team road tested and put the MC thru it's paces to find out why MC steering heads are set with the wheel way out in front like they are. One of the things they discovered was that the MC suffered badly from dive under hard braking and it had a problem across pot holes. The major factor that interested me was they received substantially better fuel economy. To me that means lower drag. Hence I'm thinking that this could be a worth while experiment with a gravity bike. So I made two balsa models with 20mm alloy wheels. One with the steering set with the head vertical the other set at 70 degrees. I then ran them down a narrow fenced ramp to keep them running straight and timed them and raced them over a two metre distance to the best of my ability. Every time the vertical head machine won handsomely. I swapped wheels around and repeated the experiment - same result. Interestingly the vertical head machine would stay upright for a lot longer than the other which complies with another thing they said with the mc - it was a lot easier to ride with hands off the handle bars. So I was thinking of giving the vertical head a try with my composite bike cause for me it's easier to change a composite than to cut and weld. What are your thoughts? ..........trikes
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Post by John Richards on Sept 7, 2007 15:49:41 GMT
hey scott! interesting test but shopping trolley instantly springs to mind!!! i have all the gear to test such a theory and would be happy to do it for you full scale,just one thing though, how much trail did they use? if you could perhaps knock up a drawing for us we have a donor bike to try out your thoughts on it has a ruined head stock from chops crashing that i could easily re-set to 0 degrees cheers john
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Post by trikesrule on Sept 7, 2007 21:33:00 GMT
Hi John Chops crash. I don't believe it Ha! Was he heving a drink at the time. It's ok Chops I've put mine down a couple of times trying to get the darn thing sorted out. It's led me to drinking more to numb the pain (I think it worked). Don't have a drawing as I built the models with a shopping trolley in mind. Set models up with about the equal of 65mm trail. You know I see other tangible benefit's from this simple idea. A) Have more 'room' on the bike (for me) to build a data acquisition digital dashboard. B) Better aero around the front wheel as the forks could be composite (or sheet steel) and could 'accidentally' be made aero shape and be made a little wide (side view) and you could bend direct the air to get better flow around yours and Chops legs. Also something else struck me that it might do us well is to make a bike with adjustable trail as I've learned there is the ultimate set up for every course. There appears to be a relationship between the CoG and where the front wheel footprint is. As in the steeper the course the further back the CoG needs to be or so I found with my Trikes. I think it's great that you're prepared to play around also (don't tell the wife). Seems to me that anything that requires a force / torque to keep it straight (steering for example) has got to be costing speed thats why I run zero trail on my steel bike. Guys in the US say I probably should run some trail to keep the bike running straight and because they have trail in their MC'. But basically I'd (we'd) only end up with a bike as fast as theirs. I didn't get to where I am now by not playing around some so in the interest of kicking US butt lets play around and see if we can't find a bit more..........trikes
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Post by John Richards on Sept 9, 2007 16:50:28 GMT
hi scott have been thinking about this thing this afternoon, it seems to me that it might want to straighten its self up in the corners or perhaps want to snap right round (like a shopping cart wheel) but will give it a try for giggles, will let you know how i get on and will base it around 65mm trail. cheers john
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Post by trikesrule on Oct 7, 2007 4:02:18 GMT
Hey JR hows the experiment coming along? Got a mobile. Send it to me wymans @bigpond.com I'll call u as my Boss pays my mob bills.........trikes
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