What is double-declutching and how do you do it? Nifty footwork!

Driving a Fiat-500-based Autobianchi Bianchina was an ideal opportunity to demonstrate why you need to double-declutch when there is no synchromesh, and show how you do it. See also the Austin 12 Heavy test video, where some pedal-dancing was required!

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[vwestlife]

In the U.S. it's simply called "double-clutching". No "de-". And unlike the trucks (lorries) in Europe, our big-rigs here still don't have synchromesh gearboxes. But instead of double-clutching, most truckers in North America usually don't press the clutch at all when changing gears on a non-synchromesh gearbox. If you get your timing right, it's easier that way.

[GodfreyMann]

What he doesn’t explain is that he’s using the clutch the first time to take the car out of gear, then a second time to put it into the next gear. This makes it easy to follow/understand what’s happening and therefore how to do it oneself if ever faced with the situation. With this concept in one’s head, timing/coordinating the entire sequence becomes a piece of cake.

[robertlambert]

My dear old Dad taught me to double declutch, back in the late 1970's. Definitely an art not everyone can master, so hats off to you, Ian. I still do it occasionally in my modern car when the gearbox is cold, just adds to the driving experience!

[adelestevens]

I actually first learned to double declutch in an ancient Bentley and it was a right horror after driving my first owned car which was a mk2 Ford escort.
I learned to crash-box from a capri which had a snapped clutch cable which I couldn't afford to replace until payday....a month away, so I got rather expert at that lol.

[MattBrownbill]

I have had so many cars with duff gearboxes and or clutches, I find myself doing that on gear changes, or at least pausing in neutral and not going straight through. I do it out of habit now, don't even think, regardless of the car I'm driving.

[patrickw]

I remember my Grandmother talking about double declutching. I imagine she became weary of it in the end. After Austin Sevens, Fiat Topolinos, and 500's she went automatic by the 1960's with Fiat 850 Idroconverts and a string of DAFs.

[lukec]

I learnt how to double declutch into first in a 2CV when I was 14! Still do it when changing down for an overtake in modern cars as it's smoother. A great skill all should learn.

[johnscarsandstuff]

It is good that you could demonstrate double declutching in fewer than four minutes, it shows that it really isn't difficult. I taught myself the technique as a new driver many years ago, it certainly helped with the recalcitrant gears in my Mini Metro. Synchromesh itself is like mini clutches (not gears) that engage before the dog clutches that actually transmit drive. I suspect the Austin 12-4 didn't even have constant mesh for its lower gears (hence the wonderfully musical gear whine).

It helps to know your car and the spacing of the gear ratios; the difference between fourth and third gear is usually less than the difference between third and second, which is usually less than that between second and first. That's why the change into top on a four-speed box probably feels easier than any other, the revs need less time to drop or (on a synchromesh 'box) there is less work for the synchronisers to do. Knowing the relationship of the gear ratios gives you an idea of how much of a pause to leave when going up, and how much of a blip when coming down. I remember the owner of a vintage bus telling me that the best way to time the pause when going up the (crash) 'box of his machine was to recite the first two lines of the Lord's prayer. I suppose even if the timing was off, you could always rely on divine intervention to smooth the change.

[DaimlerSleeveValve]

Well done! Proper footwork there (though I'm betting a few crunches were edited out). As you said, double-declutching is rarely needed when changing up, though my car has an alternative arrangement. Press the pedal and the clutch disengages as expected. Press further and a brake is applied to the shaft, giving a very fast change in one operation. The owner's manual describes the processes in detail, and tells you that you should practice on a slight downhill.

[davidcooke]

My first proper experience doubling was in an AEC Regent!
That punished you if you got it wrong by making your wrist feel like it was being snapped!
They sound so innocent and sweet when they’re ticking over, then you put the clutch in and engage 1st and all hell breaks loose next to you!😮
Great vid mate!

[Daddysboys]

I drive all of my cars like this!
😁✌🏼

[MeMe-qrgo]

Great little instructional video Ian. When I first started learning to drive lorries, the training school insisted that we learned double de-clutching despite the fact that none of the lorries they taught in had crash gearboxes. It would have been fair enough if crash gearboxes were still a thing but this was 1998! Not many haulage companies ran vintage Fodens! Even more inconvenient was the fact that they expected you to do it all the time including during your test! The other trainee on the lorry that week didn't double de-clutch on his test and passed but I did and failed!
Rant over. I got there in the end.
Great video. Thanks!

[jfv]

In my days as a student i had a side job as a taxi driver. A Slowwww Mercedes w123 200D. I tought myself to double declutch in that car🤣
Later i got good use out of that skill and knowledge when i was 200+km from home when the clutch cable snapped (Opel Corsa A). I proceeded to drive it home the entire 200+km by just floating the gears in and out and rev matching up and down the gbox as needed. Quite challanging!

[leonardosimm]

I was taught to DDC on my first police driving course (1980s, using Astras, Maestros and Chevettes). They still taught it as late as the mid 90s on advanced courses; tradition rather than necessity with more modern cars, however when 'making progress', DDC-ing (with a throttle blip) does make for somewhat smoother downshifts at high revs. It's a useful knack at which to be proficient.

[Zadster]

I don't double declutch very often, but it can be so satisfying to get just right. Very much part of the art of motoring. Many modern cars seem to have engine management that inserts "rev hang" as you change up - it opens the idle valve to keep revs up when you take your foot off the throttle and theoretically make up-changes better. In reality, it just gets annoying. The same cars all feel like they have big flywheels (not just diesel DMFs, smaller petrol too) which means when you blip the throttle they don't respond very quickly and it can really slow down down-changes.

[katierscott]

I taught myself to double declutch due to having cars with knackered gearboxes years ago. I still do it as even with a syncro gearbox, downshifts when dropping a gear due to, for example, needing the lower gear for a hill, is so much smoother double declutched. When i did my blue light ambulance training, my instructor exclaimed 'where did you learn to double declutch'. Clearly a rarely known skill he was surprised, impressed and pleased all in one go. He encouraged me to keep doing it as it helps keep the journey smooth for patients.

[EVguru]

It seems quite a lot of commentors don't know the difference between non-syncro and a crash gearboxes.

In a crash gearbox, the gears themselves are being slid in and out out of mesh. You have to get the teeth of one gear to fit between the gaps of another gear. The gears have quite a lot of teeth, so those gaps are really quite small. Crash gearboxes are mostly found in vetteran and vintage machinery.

It's particularly difficult to get into gear of the vehicle speed is changing. This is the origin of the rule about not coasting out of gear. Brakes didn't used to be up to the job of controlling speed on a long decent without the assistance of engine braking and If you were out of gear, then you might suffer brake fade and run out of control.

Something like the Autobianchi will have a constant mesh gearbox, with dog clutch selection of the ratios. The teeth and gaps of the dog clutches are fewer and larger, giving you a much better chance of slipping the teeth into a gap. Nearly all motorcycle gearboxes are constant mesh and have a speed reduction between engine and box, which makes the gaps even easier to find (BMW boxers run the gearbox at engine speed and have a poorer reputation for easy changes).

A synchromesh gearbox is also a constant mesh gearbox, still has dog clutches, but also has a mechanism for bringing the two halves of the dog clutch to the same speed before they actually engage. At it's simplest, this would be a cone type friction clutch.

[Vonononie]

My old 1958 Morris Minor had no synchro on 1st so I just learnt how to drive rarely using it. 2nd was okay at low speed so I’d creep up to lights and give ways, and pull away in 2nd. Saw a MM Traveler creeping up to traffic lights a few months and it brought back memories!

[bombakdik]

Even with synchromesh equiped modern ish cars, it sometimes help to get a smooth third to second so to be sure to not ruin a synchro that is becoming a bit tired or lazy, even when it is honestly just due to age and normal wear and tear and good maintenance. On some boxes it is simply inevitable.
Nicely demonstrated!
A major key to get better at it is to learn yourself to not rush it. Doing it slower will get you doing it faster ;)

[IanOS-UK]

Another fab video, Ian 😊 When I did my Met Police driving courses back in the 80s, we were all taught to double de-clutch on every change, both up and down, even though the cars and vans all had synchromesh. Funny thing is, it became such a habit through so much driving, I still do it even now; all these years later! It does make for a smoother change and I believe eases west on the gearbox.