kwaka jack Posted March 4, 2011 Report Posted March 4, 2011 Hey guys after watching this video of rossi and andy im a little confused at the final part of the video (6 mins. 10) where andy say's coupled with the throttle closed and the front brakes on will aid the bike to turn into the corner. How does this work? how i understand it is having everything done just before you turn in to have a stable bike and the correct distruibution of weight accross the tyres im prob just being stupid and not looking at the whole picture lol jack
Bullet Posted March 4, 2011 Report Posted March 4, 2011 Jack, If you think of the scenario as this. When your on the throttle, the bike shifts weight towards the rear and the forks extends. (think of this picture as if you were riding a chopper/harley). Now, if you're on the brakes the weight moves forwards and the forks compress so the bike becomes a lot quicker to steer, (so think of this as a sportsbike in comparison). It's all to do with the trail of the bike, slow steering bikes have a lot of trail, they're very stable but slow to steer, fast steering bikes have much less trail, and turn much, much faster, but can be a little less stable and this is the situation that you can create from the scenario Andy is talking about in the video. I hope that makes sense? Bullet
kwaka jack Posted March 4, 2011 Author Report Posted March 4, 2011 yes completly understand that, same effect as moving the forks through the yokes to make it turn quicker, will have to give that a little try next time im out cheers
Bullet Posted March 4, 2011 Report Posted March 4, 2011 yes completly understand that, same effect as moving the forks through the yokes to make it turn quicker, will have to give that a little try next time im out cheers Yeah exactly the same, though motorbike forks have about 4-5 inches of travel, and you only move the forks through the yokes a few mm's (hopefully). Bullet
kwaka jack Posted March 4, 2011 Author Report Posted March 4, 2011 yes completly understand that, same effect as moving the forks through the yokes to make it turn quicker, will have to give that a little try next time im out cheers Yeah exactly the same, though motorbike forks have about 4-5 inches of travel, and you only move the forks through the yokes a few mm's (hopefully). Bullet hopefully yea might have a little more to worry about than the front end turning in a bit to quick if they go a bit further lol
Cobie Fair Posted March 4, 2011 Report Posted March 4, 2011 You guys got it on this, just want to mention rake too, as that changes with more weight on the front, and from the forks beeing moved up, or down. CF
faffi Posted March 4, 2011 Report Posted March 4, 2011 I remember this issue being up when I first joined, this topic was up, but I don't think there was a unison conclusion that braking made turning in quicker? I seem to remember claiming trail braking eased turn-in, but there were arguments why it wouldn't that I've forget Unfortunately, I cannot find the topic again, but I found this: One thing you have to take into account is that the trail increases by up to 25mm under heavy braking. Trail is measured at the CENTER of the contact patch which becomes way different under hard braking, it moves rearward. 25mm of trail is enormous and is no doubt what contributes to the heavy feel you get at the handlebars under braking. So while the rake and wheelbase go towards a quicker turning machine the shape of the contact and its new location are huge offsetting factors. Keith Also, won't the same forces that makes the bike want to stand up and run wide if the brakes are hit mid-corner also come into play when trail braking? Some related topics http://forums.superbikeschool.com/index.php?showtopic=562&pid=3174&st=0entry3174 http://forums.superbikeschool.com/index.php?showtopic=2136&pid=16790&st=0entry16790 http://forums.superbikeschool.com/index.php?showtopic=11&pid=15&st=0entry15
kwaka jack Posted March 5, 2011 Author Report Posted March 5, 2011 ] Also, won't the same forces that makes the bike want to stand up and run wide if the brakes are hit mid-corner also come into play when trail braking? that's exacly what i was thinking Eirik but ill give it a go, also do u have to time it so the brake is completly trailed off once you're reached the desired lean angle or is it just to get the bike to turn quicker for the enitial bit of leaning the bike over or is it all just do to prefrence? cheers for the link
Crash106 Posted March 6, 2011 Report Posted March 6, 2011 I generally like to be off the brake, with my arms relaxed, before I turn. For me, I do better focusing on turning once and easing on tha throttle rather than trying to change the geometry of the front end AS I'm riding. That being said, I also don't see a problem using a little front or rear brake to adjust speed or make me more comfortable. At anything close to the posted speed limit, I should have plenty of traction to add front brake and turn quicker (although honestly, isn't it the job of the handle bars to turn the bike), or drag the rear brake when leaned way over. Dragging a little rear brake should have less effect on ground clearance compared to chopping the throttle, hitting the front brake or (say it ain't so) doing BOTH. YMMV. I'm not a racer, so maybe a tenth here and there is more important to you, while I'm aiming for comfort and joy.
kwaka jack Posted March 7, 2011 Author Report Posted March 7, 2011 well i sharnt be practicing pivot steering or braking on entry for a while i highsided today :( :(
Bullet Posted March 7, 2011 Report Posted March 7, 2011 well i sharnt be practicing pivot steering or braking on entry for a while i highsided today :( :( Ouch, what did you, how? You ok, injured? bike? Bullet
bradvanhorn Posted March 8, 2011 Report Posted March 8, 2011 well i sharnt be practicing pivot steering or braking on entry for a while i highsided today :( :( Ouch, what did you, how? You ok, injured? bike? Bullet Yes, please let us know how you're doing. Real sorry to hear about the crash.
kwaka jack Posted March 8, 2011 Author Report Posted March 8, 2011 got a fractured ankle where the bike landed on it, bike is a bit of a mess from what i can see its plastics damage but will need to look in further detail, was a combo of cold back tyre and bit to much throttle.........serious school boy error
Cobie Fair Posted March 9, 2011 Report Posted March 9, 2011 got a fractured ankle where the bike landed on it, bike is a bit of a mess from what i can see its plastics damage but will need to look in further detail, was a combo of cold back tyre and bit to much throttle.........serious school boy error You aren't the first that has been bit by those 2! But, stil sucks. Get that ankle sorted out! CF
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