Rev Matching
 

Hey,

Can someone please explain to me what is Rev Matching and how its done? Would you suggest that to a begginer?

Thanks!
Pedram

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.

Thank you very much!

Incognito explained it very well.

I've gotten in the habbit of just blipping the throttle in my car, and on my bike whenever I downshift, unless I have come to a stop.

Of course, I like trying things like heel-toe, double clutching, etc... in cars, so maybe I'm just weird that I do that.

Why would you double clutch in a car? I used to have to do it when driving semi trucks because they wouldn't shift properly if you didn't.

You must have never seen Fast and the Furious. lol... sorry!

"Granny shifting, not double clutching like you should." -Vin Diesel

Why? Because it's better for the drivetrain just like it is in big trucks. Just it doesn't matter as much in cars. I'm also looking into racing in my future, I'd rather have a good habit now then have to learn it later. This just gives me more practice. The only thing I don't really use when I'm driving on the street that I would in racing is left foot braking, because it really is not needed at all on the street.

I thought that is why they invented synchros...

There's no such thing as double clutching a modern car. You either have a dct tranny or you dont.

Unless you've blown out a syncro and refuse to repair it i guess.