northern - on amount of throttle etc, if you place your hand on throttle
at 'off' then extend fingers to/across brake lever, then return them to bar,
thats about your general riding wrist position,, from which you would
need to make a strong downward/forward wrist movement to cause
stronger acceleration..
seems like nothing, but try out your throttle/braking hand position
on the bike but engine off,, find your comfort zone within that
position [thumb around throttle off but fingers extended over lever]
then practice riding around there.. relax wrist a little as taking hold..
means you start from a position of easy off throttle
but need a bigger fistfull for full acceleration..
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Actually, you can press the brake pedal and blip the throttle on a car as well. It's called heel & toe. I always rev matched when I drove a manual car.
I think it's a good habit to rev match on a bike as well when downshifting. Otherwise, I assume you are slowly letting out your clutch when slowing down, possibly taking you more distance to slow down. With practice, if you rev matched, you'll find that you can actually use more engine braking than w/o rev matching.
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You're actually supposed to rev match your downshifts in a car as well, have you ever seen the heel-toe braking/clutching racecar drivers use?
It's absolutely unnecessary if you're cruising down the street. Just like a car you can just pull the clutch in and downshift all the way into the neutral if you want to. That's usually what I do, actually.
If you're serious about racing than you should definitely learn how to rev match your down shifts, though.
In referenced to your question on how you do it, there's really no set amount of throttle you should give the bike, you just learn where the revs are. Say you're in 4th going 40 mph. You know when you downshift into 3rd going 30 mph, you want to be at around 6.5k revs. So you lightly apply your breaks with you index and middle fingers, while you lightly roll on the gas to bring the engine up to 6.5k rmp. Then, you downshift and let the clutch out.
here's a beautiful example of how "blipping" or rev matching is done. Obviously most people can't do it this well ( I know I can't), there's a reason David Johnson is a professional and the rest of us aren't :P.
But anyway, he illustrates the technique beautifully
I heel and toe sort of in the car all the time. Except when I have shoes on my shoes are wide enough to use one side of my foot for the brake and the other to blip the throttle.
Not rev matching upon downshift is rough and I dont ever do it on either the bike or in the car.
I have actually been wondering this same thing lately. I find that AT LOWER RPMS (as in sub 5K), I can pull in the clutch, kick down a gear, lightly apply rear brake, and simultaneously let the clutch out easy, WITH NO THROTTLE... Which is, what I believe, northern is asking about. It's actually pretty smooth and does a good job slowing the bike when coming to a stop light.
The question is, in this situation, am I harming the engine/clutch by not utilizing the throttle??
The more I've read about it on various car forums, this process I detail above is actually "slipping" the clutch and is not good.. but this is about cars, not bikes, and as such a dry clutch...
I don't usually try to match rpms while shifting. I think it's a good idea, if only to reduce chain snap especially when shifting while climbing or descending a steep hill, but it would take some serious practice to get it right as some have said.
In an automobile, where the only gear that's moving is the one in use at the time of the shift, there are devices called synchronizers that engage as you begin to move from one gear to another. They spin the gears to the proper speed for smooth engagement. You can actually hear them working if you shift slowly enough. Motorcycles OTH have gears that are continuously engaged so do not use synchronizers. In theory the "constant mesh" transmission should make shifting smoother and use of the clutch optional. I suppose to some extent that's true. You can easily change gears at moderate rpms w/o using the clutch but it does strain the drivetrain. Hence the inclusion of the clutch.
Some racing bikes use a "slippy clutch" to make downshifting at speed smoother. This is a clutch that slips by design when downshifting thus preventing chain snap. I read somewhere that a new Kawasaki sport tourer, I can't recall which one, can be equipped with one of those. I'd sure like to try that on my CBR.
Dave
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Probably it would be ideal to match the revs with the gears when downshifting in a car but I have drove many different cars (all manuals) and never did that and never had a problem. In fact my CRX had over 200 thousand miles on it and the transmission was still in good shape. Every time I downshifted, I just made sure I floored it after dumping the clutch.
CBR250r
