Rev Matching
#11
05-30-2012, 09:39 AM
Basically, you're matching the engine revolutions with the wheel revolutions, and thereby maintaining stability throughout the drivetrain/chassis when transitioning between gears; example:
Say at 45MPH in 3rd gear your engine is at 3500 RPM and you wanted to drop to 2nd gear to pass a car up. Now let’s say that at 45MPH your engine spins at 4000 RPM in 2nd. That's a 500 RPM difference, see? While transitioning into 2nd gear you'd want to increase your throttle and thereby bring your RPM up to 4000 so that when you release the clutch you don't have that moment of instability and sudden jerk. The transition between gear change becomes more synchronized and smoother.
No let's say we're UP shifting using the same engine & gear ration (hypothetical speaking). You want to go from 2nd to 3rd at the same 45MPH. In this instance you'd want to drop your RPM by 500 (from 4000 to 3500) so that when you release the clutch lever you again don't get that jerking. The chassis remains stable and the shift is easier on the bike.
Is it absolutely necessary to do this? No. Some if not most folks go through life driving manual cars without giving engine speed or rev-matching a single thought. Heck, my wife is a prime example. On a car however, it's really not very important. But on a motorcycle, matching engine speed to road speed can be critical, particularly at high speeds.
As a beginner, you should definitely start good habits like this. It's easier to learn something the right way the first time, than to un-learn bad habits later on. Before you know it you'll be doing it without thinking about it.
Just FYI, I initially learned about synchronized shifting when I became a semi-truck driver where you have to match engine speed with the transmission otherwise you’ll damage the powertrain. It's good that you're discovering this on your own.
Say at 45MPH in 3rd gear your engine is at 3500 RPM and you wanted to drop to 2nd gear to pass a car up. Now let’s say that at 45MPH your engine spins at 4000 RPM in 2nd. That's a 500 RPM difference, see? While transitioning into 2nd gear you'd want to increase your throttle and thereby bring your RPM up to 4000 so that when you release the clutch you don't have that moment of instability and sudden jerk. The transition between gear change becomes more synchronized and smoother.
No let's say we're UP shifting using the same engine & gear ration (hypothetical speaking). You want to go from 2nd to 3rd at the same 45MPH. In this instance you'd want to drop your RPM by 500 (from 4000 to 3500) so that when you release the clutch lever you again don't get that jerking. The chassis remains stable and the shift is easier on the bike.
Is it absolutely necessary to do this? No. Some if not most folks go through life driving manual cars without giving engine speed or rev-matching a single thought. Heck, my wife is a prime example. On a car however, it's really not very important. But on a motorcycle, matching engine speed to road speed can be critical, particularly at high speeds.
As a beginner, you should definitely start good habits like this. It's easier to learn something the right way the first time, than to un-learn bad habits later on. Before you know it you'll be doing it without thinking about it.
Just FYI, I initially learned about synchronized shifting when I became a semi-truck driver where you have to match engine speed with the transmission otherwise you’ll damage the powertrain. It's good that you're discovering this on your own.
#14
07-14-2012, 08:03 AM
#15
09-11-2012, 03:20 PM
I just slip the clutch to bring the rpm up and then downshift before releasing the clutch completely. Rev-matching is used for downshifting, not upshifting. You're shifting into a lower gear to increase the ratio of engine speed/road speed. Higher engine speed>>>more power at the same road speed. I usually shift without the clutch if I'm rolling on the throttle hard, or after 3rd. Much easier on the engine/transmission if done correctly.
#16
09-12-2012, 03:09 AM
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#17
09-17-2012, 10:04 PM
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play around with it. maintain a steady speed and down shift into the lower gear. watch what engine rpms spike to in the lower gear. shift back into original gear and maintain the original speed. make the downshift back to the lower gear only this time when you have the clutch pulled in, blip the throttle to the rpm spike you saw earlier. timing and a quick release of the clutch are both key
Last edited by colorado_steve; 09-18-2012 at 10:55 PM.
#18
09-18-2012, 02:17 AM
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#19
09-18-2012, 10:53 PM
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