Changing gears without using the clutch

[Lalvaz]

Hey guys,

Yesterday, was reading one of the supplements with the Hindustan Times, and saw this article on how to prolong your clutch life. The article said that you could change gears without using the clutch in order to prolong clutch life. Caveat was that you should know how to do so, but there were no instructions on how to do so.

I used to think that pressing the clutch was essential to be able to change gears, since that was the only way of disengaging the engine from the driveshaft, and then you could change the gear. I guess I was wrong.

Anyways, am curious to know how does one change gears without using the clutch? How does it work and are there any issues that might arise as a result of this?

Thanks!

[sukiwa]

Don't believe in non-usage of clutch while changing gears to prolong clutch life, but I could be wrong.

Not sure about technicalities involved in this, but this is similar to the saying 'Most secure computer/system is the one which is not connected to any other computer/Internet'.

[dadu]

You can , ppl used to before the syncromesh was invented. I dont know exactly how its done but I guess you will have to listen to the engine and match the speed with the vehicle before changing.

Its probably an art to listen and then change the gears without the clutch but can do a lot of damage in todays setup, if not done properly.

[Thad E Ginathom]

We have talked about this one before.

Suggesting it to prolong clutch life is utter nonsense. There are many drivers who have never had to replace a clutch; it depends on good usage.

It is not changing gear that wears your clutch out: it is slipping the clutch, holding the car on the clutch on an incline --- stuff where friction is happening between the clutch plates for more than a few moments. Even resting the foot on the pedal.

The combination of syncro-mesh and clutch means we don't have to be too fussy about engine speed when changing gear, although, of course major mistakes lead to uncomfortable jerks and stress on the poor car. Equalise the speed of the two gear cogs that are coming together by getting the engine speed right and --- no clutch needed!

Certainly it can be done. I don't claim to be able to, but I have seen it.

Engine speed is what it is all about. This was a Thad's-Dad trick; driving, even on hilly, winding roads, without using the clutch --- but he only did it as an occasional show-off trick. I'm sure that if it had any financial benefit, he would have done it more often!

Probably many of actually come close much of the time. Consider that the text-book method is to fully disengage the clutch, pressing the pedal to the floor, while changing gear. The realise that what we actually do, many times, is just a quick dab on the pedal as we change.

In my opinion, the guy who wrote this has shares in a gearbox company. If people take it as serious day-to-day advise, many cogs are going to be damaged as people try it. I guess most people, after the initial graunching noise just won't ever try again, and will spend the rest of their lives stating that it is impossible.

As general advice, it is stupid and irresponsible. Gear boxes are a lot more expensive than clutch plates!

<cross-posted> Dadu, yes you are partly right. The clutch was used in the days before syncromesh. When changing down it was necessary to "double de-clutch". This involves de-clutching, changing to neutral, taking foot off clutch, reving engine to speed up the cogs on the engine side of the box, pressing the clutch again and engaging the lower gear. Have to say that I tried this only once, and it is harder than it sounds! But only a real non-syncro gearbox would test you out: a syncromesh gearbox would absorb the mistakes.

I suspect there may be stuff llike old trucks on our roads that still don't have syncromesh?

[androdev]

it is like catching a fast cricket ball with your teeth. one can do this in theory, by making the relative speed = 0, and then decelerating to rest slowly. any small mistake can hurt real bad.

btw, it is safe to get the car out of gear to neutral without using the clutch but engaging into gear is risky. just apply gentle pressure on the gear knob to slot into neutral (but not enough to actually slot into neutral) and hold it under this pressure and let go off the accelerator. as the car begins to slow down, at some point the RPM match happens and the stress on the tranny will be zero, then it will slot into neutral without clutch.

[ashthedivx]

Originally Posted by Thad E Ginathom

It is not changing gear that wears your clutch out: it is slipping the clutch, holding the car on the clutch on an incline --- stuff where friction is happening between the clutch plates for more than a few moments. Even resting the foot on the pedal.

Oh god... I have been holding clutch on inclines and straight lines to get better fuel economy, so as i'll not need to revv my engine and car flows in usual speed and once pickup is required i can release clutch and come back to previous gear easily. Didn't knew that it will wear clutch faster then normal circumstances.

But, I am still confused how come clutch will wear fastly when practically we ain't using the clutch. Can you clarify the doubt ???

[diabloo]

Is this same as Heel n Toe, which is discussed to death here?

[watashi75]

This technique is called speed shifting and is sometimes used in car racing to shift without using the clutch. There is some information here on this and other such advanced techniques -

http://www.team-bhp.com/forum/collec...e-driving.html (The Manual On Extreme Driving!)

However contrary to popular belief there is no significant gain in time and there is a greater risk of damaging your gears.

I am not sure if this technique can be used for both downshifting as well as upshifting. Can somebody calrify?

[Mr.Bangalore]

well i have tried changing the gears without clutch in my bike, but never tried it on Car. One financial benefit is that FE increases defently if you dont use clutch and dont know about the clutch life though.

[supremeBaleno]

Not tried it with cars (and don't really plan to), but many a time with my bike and yes possible to do it by listening to the engine. This was not to prolong clutch life or anything, but just for the heck of it. Curiousity factor being the introduction of the geared, clutchless bike Street by HeroHonda many years ago.

[Thad E Ginathom]

Originally Posted by watashi75

I am not sure if this technique can be used for both downshifting as well as upshifting. Can somebody calrify?

Yes, it can. You have to increase engine speed to match geerbox.

Originally Posted by ashthedivx

Oh god... I have been holding clutch on inclines and straight lines to get better fuel economy, so as i'll not need to revv my engine and car flows in usual speed and once pickup is required i can release clutch and come back to previous gear easily. Didn't knew that it will wear clutch faster then normal circumstances.

But, I am still confused how come clutch will wear fastly when practically we ain't using the clutch. Can you clarify the doubt ???

Any situation in which the clutch is neither fully engaged nor fully disengaged will lead to wear, as there is friction between the plates if they are not totally locked together and thus rotating at the same speed.

On an incline the car should be held on the brake until ready to move.

In real life, I find city driving impossible without some clutch slipping in traffic queues (just releasing the clutch a little to edge the car forward when it would be travelling too fast in 1st with the clutch engaged) and for brief stops on inclines, like at a junction. I don't, however, drive with my foot resting on the clutch, ever --- so not all bad!

[sudev]

Done that and can be done shifting up or down. But not with purpose of saving clutch. Come on cost of clutch is much less than a "kaput" gaer box at worst or even " worn out synchro-gear rings.

In theory the two gears inside your gear box have to be at same revs to slot in (further helped by synchro rings) The driving gear is rotating as per engine rpm's and the driven gear (while not slotted) is rotating with wheel rpm's. If you can get both at same rpm's you can slot in the gears to lock with each other. When you press the clutch this is what is happening. The engine side gear is free wheeling because of clutch and can easily slot with driven gear.

First to do a change to neutral you need to practice slight easing off accelerator and pushing the gear to neutral. This is easy part.

Second do get in to the next gear (say second to third) just wait a second in neutral and then push the lever towards third - all the while keeping off accelerator. As soon as gear revs match the gear will slot in to place.

Problem is doing in other direction (third to second) where you need to pump accelerator to rev up the engine and then let it slow down enough so that again revs on both side match up and gear slots in.

Have driven in emergencies on plains and even in hill but it is something to be done with extreme caution and only if you have practise.

BUT again this is no way to save the clutch and if that is the intention then you may save the clutch only to land up with much bigger bill of gear box.

[alpha1]

I used to do that on my bike whenever the clutch wire broke.

But would not advise anyone doing it - of course if you wanna screw your gear cogs - then proceed by all means.

[Rehaan]

Originally Posted by androdev

...by making the relative speed = 0 ....

Exactly!

Originally Posted by ashthedivx

Oh god... I have been holding clutch on inclines and straight lines to get better fuel economy, so as i'll not need to revv my engine and car flows in usual speed and once pickup is required i can release clutch and come back to previous gear easily....

Bad for many reasons.
See this post, you will find your answers :http://www.team-bhp.com/forum/techni...tml#post226145 (Shifting to Neutral or Pressing the Clutch when Braking - Is this right?)

Originally Posted by supremeBaleno

...Curiousity factor being the introduction of the geared, clutchless bike Street by HeroHonda many years ago.

...though that really doesnt work in the same way. However, some new electronic-manual transmissions found in sports cars do, if i am not mistaken.



Lalvaz,

Please search next time before creating a thread. This has been brought up many times before :

http://www.team-bhp.com/forum/techni...ut-clutch.html (shifting without clutch)

http://www.team-bhp.com/forum/techni...ut-clutch.html (Shift without clutch ??)

And redirected to other similar threads where the topic was touched upon :

http://www.team-bhp.com/forum/shifti...le-breaks.html (wat do you do if the clutch cable breaks)

http://www.team-bhp.com/forum/techni...nge-gears.html (How to change gears)

http://www.team-bhp.com/forum/collec...son-2-use.html (Whats double clutching & whats the reason 2 use it)

cya
R

[Alfa_Kilo]

I have done it a few time with my 540 when the clutch actuator failed. One has to match the engine speed with the vehicle speed and then gently shift into gear from neutral. It does not take long to get the hang of it. The problem is in moving from a standstill, which requires slotting the vehicle in 1st and cranking the engine, quite a pain in start stop city traffic.