Cobie Fair Posted December 19, 2013 Report Share Posted December 19, 2013 Right on guys, exactly. Just to go all the way with this: if the front corrects, and the rider does ANYTHING to the bars, its going to be the wrong thing. Super light touch (after the steering is done). Easy to say, but... CF Quote Link to comment Share on other sites More sharing options...
ktk_ace Posted December 20, 2013 Report Share Posted December 20, 2013 Right on guys, exactly. Just to go all the way with this: if the front corrects, and the rider does ANYTHING to the bars, its going to be the wrong thing. Super light touch (after the steering is done). Easy to say, but... CF Possibly one of the hardest SR's to correct. I say even harder than letting go after breaking up Quote Link to comment Share on other sites More sharing options...
Cobie Fair Posted December 20, 2013 Report Share Posted December 20, 2013 Yeah, know what you mean! Possibly one thing that makes it even more of a challenge is when a rider really is working to get the bike turned quickly, and that can take a lot of force. This year I surveyed a number of students to give me some idea how much pressure they would use to turn a bike quickly, at a high speed turn. None was even close to what is needed. The amount of pressure they pushed against me with would have made a minor change in lean angle, slowly--at a high rate of speed. Hmmm...wonder if we could get some sensors on handle bars and measure this...sounds like another thread though. CF Quote Link to comment Share on other sites More sharing options...
benhamf15 Posted December 20, 2013 Report Share Posted December 20, 2013 Sounds like another new bike project for Will to put together... Quote Link to comment Share on other sites More sharing options...
rchase Posted December 20, 2013 Report Share Posted December 20, 2013 Yeah, know what you mean! Possibly one thing that makes it even more of a challenge is when a rider really is working to get the bike turned quickly, and that can take a lot of force. This year I surveyed a number of students to give me some idea how much pressure they would use to turn a bike quickly, at a high speed turn. None was even close to what is needed. The amount of pressure they pushed against me with would have made a minor change in lean angle, slowly--at a high rate of speed. Hmmm...wonder if we could get some sensors on handle bars and measure this...sounds like another thread though. CF Did the people who got it right help you back up off the ground? That would have been the nice thing to do. Quote Link to comment Share on other sites More sharing options...
Lnewqban Posted December 22, 2013 Report Share Posted December 22, 2013 ....................Super light touch (after the steering is done). Easy to say, but... If I understand it correctly, a lot of force on the bars for quick steering is followed by a super light touch. However, quick steering and the associated steering force must be dialed down some when riding on wet surfaces, IMHO. Quote Link to comment Share on other sites More sharing options...
Cobie Fair Posted December 23, 2013 Report Share Posted December 23, 2013 For sure less speed/traction and pressure needed in wet. Wonder what it would take to get some pressure sensors on the bars...any of you know? CF Quote Link to comment Share on other sites More sharing options...
rchase Posted December 23, 2013 Report Share Posted December 23, 2013 Hmmm. Good question. Strain gauges are used on quick shifters but those have a limited range of movement and are just used to tell the ECU when to stop the spark for the shift. You guys might want to get in contact with an engineering firm that does custom stuff. Here's a good start. There might be other options out there already. http://www.omega.com/prodinfo/StrainGages.html I think it would be interesting for you guys to equip the camera bike with strain gauges and an advanced telemetry system so both the riders and the coaches can "see" what's going on even better. There's a lot of telemetry systems that have g sensors, GPS's and can even talk to the bikes onboard computers to record lots of information. Prices are dropping on this stuff by the day as it's getting more popular. Quote Link to comment Share on other sites More sharing options...
spgtech Posted December 24, 2013 Report Share Posted December 24, 2013 Hi Cobie, A strain gauge on the pinch bolt for the clip on should do it. I have a Starlane quickshifter that has a little metal doughnut about 5mm thick and 10mm in diameter which sits under the head of the shift arm pinch bolt where it clamps to the splined shaft on the transmission. The increased tension on the bolt is sensed and the shifter activated. No reason this type of sensor couldn't work for the pinch bolt for the replaceable handlebar tubes on most aftermarket clip ons. I would guess a strain gauge, a signal conditioner and a data logger. Calibrate with a spring scale. Should be pretty cheap and easy. -Sean Quote Link to comment Share on other sites More sharing options...
tmckeen Posted December 24, 2013 Report Share Posted December 24, 2013 Hi Cobie, A strain gauge on the pinch bolt for the clip on should do it. I have a Starlane quickshifter that has a little metal doughnut about 5mm thick and 10mm in diameter which sits under the head of the shift arm pinch bolt where it clamps to the splined shaft on the transmission. The increased tension on the bolt is sensed and the shifter activated. No reason this type of sensor couldn't work for the pinch bolt for the replaceable handlebar tubes on most aftermarket clip ons. I would guess a strain gauge, a signal conditioner and a data logger. Calibrate with a spring scale. Should be pretty cheap and easy. -Sean The sensor in your quickshifter isn't exactly a "Strain Gage", its more of a momentary actuator switch, It only needs to detect the application of pressure, not measure how much pressure is being applied. I'm not exactly a mechanical engineer, but I have some experience in testing force and strain gauge's, IMO the best route would be to make custom clip on bars with a setup similar to how a throttle tube slips over the right bar, place some strain gauge's between the inner and outer sleeves on the front and back, so you can measure force applied in both directions. You can then look at the pull, push and combined force for a given steering input. The guys at Omega would probably be able to give you much better insight on what kind of strain gage would work best Tyler Quote Link to comment Share on other sites More sharing options...
khp Posted December 25, 2013 Report Share Posted December 25, 2013 At work, we bought a load-cell that can measure travel vs force. IIRC, it was around USD25K, but then again it has several load cells with different ranges/resolutions. The Omega link looks interesting. I'd contact them and explain what you'd like to do/measure and see if they can recommend you how to go forward. Seasons greetings to everyone. Quote Link to comment Share on other sites More sharing options...
benhamf15 Posted December 25, 2013 Report Share Posted December 25, 2013 I would think you'd want a solution that measured force in 2 axes on each bar... both the vertical (straight down the forks) and the horizontal (in plane with the rotation of the bars). This could show how much a rider is "resting" on the bars, especially if he is holding himself up on the inside bar when hanging off (vertical measurement) as well as how much force is required to steer the bike (horizontal measurement). If you also summed up the forces too, It could be used to show how much wasted force there is when not pushing purely horizontally in plane with the bars to steer. Ideally it would be tied into the video on the video bike somehow so it could be seen in the video review. Of course, actually getting this done probably ain't so easy... or cheap. A lot of pro teams use a lot of sensors to gather telemitry data. Perhaps there's a sensor they already in use that could be adapted to this purpose. If so, it could probably be plugged directly into existing telemetrity gathering equipment making download simpler. Perhaps the data could be combined on the laptop with the video. Maybe the old BMW WSBK team has some gear they're willing to part with now that they're not going to need it anymore. Benny Quote Link to comment Share on other sites More sharing options...
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