Do you need to blip the throttle on a downshift?

Changing down the gearbox isn't one of the easiest jobs we have to do on the bike, but demands both a clear understanding of the need for good timing as well as some competence with the controls.

One of the perennial arguments amongst riders is whether or not you need to "blip" the thottle to raise the revs momentarily to make a correct gear change.

Like many things to do with riding, there's no clear cut "yes" or "no" answer as to whether it's right or wrong. So rather than come down on one side of a fence or the other, let's sit on it and weigh up the pros and cons on either hand.

First, let's just remember that I'm a road rider and not a track jockey, and that as such we're not in a rush on the road. You will find a use for matching revs on the track on a bike without a slipper clutch to avoid locking the rear wheel on a downshift.

So let's look at some the reasons that are offered for doing it.
 

It's essential for a smooth change

First, the technique itself is a hangover from clunky old gearboxes on things like Guzzis and BMWs from years back (well, OK a bit more recently on Guzzis  )... I've not ridden every single bike ever made, but I genuinely can't remember the last time I rode a Japanese bike that really DEMANDED a blip of the throttle to match revs before shifting.

Now, that's not to say that raising the revs momentarily on a downshift won't make it a bit smoother, and in certain circumstances - such as a downshift to a better gear for overtaking or maybe climbing a hill - I will twist the throttle slightly to lift the revs a little because if I don't, the shift can be clumsy.

However, when I do blip, I do not give the throttle a big twist to send the revs rocketing skyward, it's a subtle movement with a subtle result. It's always seemed to me that the big handful approach is not only obtrusive in terms of environmental sensitivity, it's as ham fisted and just as unlikely you'll match revs accurately as simply dumping the clutch with the throttle shut.
 

It's kinder to the gearbox

I've seen it argued that blipping the throttle stops the dogs in the gearbox clashing as they engage, thus resulting in a quiet and mechanically sympathetic change. This might be so, although to be honest, you'd have to judge the revs just right to avoid any loading as the various mechanical bits try to catch up with each other, and that seems unlikely to me.

However, I've never broken a gearbox and I've taken quite a few bikes to the far side of 70k miles and one to well over 140,000 miles. That last was a GS500, with a transmission originally designed in the mid 70s, and that bike was was JUST starting to whine in second... that wasn't a dog though! The reverse load doesn't wear the clutch out at any appreciable rate either.

I'm not saying the reasoning is wrong... but I think in terms of wear and tear it's not something that the average rider needs to worry about on most road bikes within the life of the bike.
 

Blipping is a more skilful technique

Why is using a complicated technique automatically equated as greater skill? Shifting gears smoothly is one of the hallmarks of a competent rider. How you do it is the important choice and particularly for a novice, smooth downshifting properly poses a considerable challenge.

To blip successfully, you either:

    dispense with braking with the front brake whilst you twist the throttle - and we wouldn't want to get into the habit of trying to straight line brake with the rear brake only would we?

or:

    learn a technique that allows you to brake smoothly with your fingers whilst twisting the throttle at the same time - easier said than done because if you don't get it right, the bike will stop in a series of jerks rather than a smooth progression

Not very straightforward for a new rider is it?

So it makes sense for a rider coming to terms with riding the bike and manipulating the controls to use a simpler technique if there is one available.

And there is - slipping the clutch. You do it to pull away, don't you? The reason the clutch is fitted is to smooth the transition between the various parts of the transmission, and it can equally well be used on down changes as well as up changes. Just letting the clutch out slowly and using the friction of the plates will spin the gears gently back up to speed.

I get my decelerating done using the brakes and the gear changes are timed so that I'm changing as I slow. I mostly avoid block changing. On a straight approach to a roundabout, it's easy to shift one at a time.

Rather than blip, you can simply let the clutch out sloooooooooowly. With the clutch smoothing out the gear change, you can then concentrate on using the front brake effectively and smoothly without the complication of the consequent twisting of your wrist tweaking the lever whilst you're trying to brake at a consistant rate.
 

It stops the back wheel from locking

Many riders get the idea that to slow from high speed you need to change down very early. You don't. So long as the motor is always in a gear and somewhere around the middle of the rev-range, you're in the right gear. Skipping on the downchange is usually a symptom of shifting down too early and forcing deceleration with engine braking rather than by using the brakes correctly.
 

Racers do it

I'll leave the reader to work out the answer to that one.
 

It makes a nice noise

Fortunately I'm not too grown up that I can't listen appreciatively when I hear a big single, twin or triple on the overrun. However, though I ride several of them, I can't feel the same about a four cylinder engine. And the environmental aspect of annoying the neighbours should be a consideration too. A wailing can might sound good on the track but a quarter of a mile from the local bypass and roundabout, it gets a bit wearing.

 

OK, so you've learned to use the clutch to smooth out downshifts and still want to blip?

So let's do the obvious thing to make the task in hand SIMPLER so you can perfect bits of it, one thing at a time.

It may well help to roll off the throttle earlier than usual so that you don't have to use the brakes to slow, and thus can practice changing gear smoothly at the appropriate moment to avoid locking the rear using the clutch-slip approach - that'll will get your timing right.

It may well help to use the simpler clutch-slip technique of downshifting so that you can now practice braking more firmly.

Having mastered the timing with the first exercise, try to roll off rather than brake and THEN practice the blipping technique - this way you won't need the front brake and can concentrate on the throttle action and timing. Remember the object of the exercise is NOT to bounce off the rev-limiter on every blip, but a subtle adjustment of the revs upward to allow the smooth selection of the lower gear.

Having got each individual skill correct, then start trying to blend them together. Slow down from the same kind of distance you were using for the roll-off method, but this time try using the brakes very gently and blip at the same time. You won't be worrying about running out of road, but will have plenty of space to play with, so that if the braking/blipping doesn't gel it won't matter.

So... blip if you want to... learn to blip if you can't... but don't feel ashamed that you don't.