Using gears to slow

[daz6215]

A bit more flexibility of attitude from the experts

Is there such a thing as an expert?

[TripleS]

A bit more flexibility of attitude from the experts

Is there such a thing as an expert?

Yes I think so, but they're not always the ones that appear to think of themselves as experts and talk down to others.

[Ralge]

A bit more flexibility of attitude from the experts

Is there such a thing as an expert?

"Expert" - that would be a has-been drip under pressure, then?

[Mr Cholmondeley-Warner]

I've thought about the "only one wheel slowing the car" thing quite a bit since a well-known coach introduced it to me. Yes, of course, if one wheel were to lose grip, only the other would be being slowed, but how often do we expect that to happen? To be clear - one wheel, up to 100% grip, the other 0%? REALLY??

So most of the time, two wheels at least are helping to slow the car.

[martine]

I've thought about the "only one wheel slowing the car" thing quite a bit since a well-known coach introduced it to me. Yes, of course, if one wheel were to lose grip, only the other would be being slowed, but how often do we expect that to happen? To be clear - one wheel, up to 100% grip, the other 0%? REALLY??

So most of the time, two wheels at least are helping to slow the car.

That would be my thoughts as well...but hey I'm no automotive engineer so quite willing to accept I may be wrong.

[Mr Cholmondeley-Warner]

True, Mark, but snow is not "normal" driving conditions ... snow will also magnify any inconsistencies in braking effort (front to rear, or side to side).

Edit: this could all be summarised as "when an axle loses grip, generally one wheel will lose grip before the other" (the differential just allows that to happen without hindrance - unless limited slip).

[Gareth]

In an open diff, there is only one wheel providing the retardation.

The same if it is a 1-way LSD as would be fitted to many fwd cars.

[WhoseGeneration]

Is the IAM's justification for slowing down entirely using the brakes and then making a single gearchange really valid?

I'm not sure what the IAM's justification is, but the System of car control says that before taking the gear, you must be at the correct speed (and doesn't dictate how you get there). If you're looking to make maximum progress, as encouraged by the IAM/RoSPA et al, you'll be wanting to use the brakes to have the shortest braking phase, and also most stable as the braking is acting on all 4 wheels. If you don't care about making progress, then the main priority is that cars around know what you're doing and it's in line with their expectations.

Chris

Or, driving within NSL and the increasing lowering of limits it will make little difference whether one brakes or just rolls off and selects a lower gear?
The ability of the driver to have used limit point analysis and the acceleration capabiilty of their vehicle might matter.
Truth is, within NSL, in many parts of the UK, progress can be made with little use of brakes.
Outside NSL is a different matter.

[f3racer]

Or, driving within NSL and the increasing lowering of limits it will make little difference whether one brakes or just rolls off and selects a lower gear?
The ability of the driver to have used limit point analysis and the acceleration capabiilty of their vehicle might matter.
Truth is, within NSL, in many parts of the UK, progress can be made with little use of brakes.
Outside NSL is a different matter.

I think that's a very good point that applies to many of the IAM's theoretical techniques. In reality when driving at <70mph, most simply don't make any difference. For example, completing all your braking in a straight line before turning into a corner. Are you really so close to the limit of traction at legal speeds that you're likely to skid off the road otherwise?

[Gareth]

Are you really so close to the limit of traction at legal speeds that you're likely to skid off the road otherwise?

Tyre technology has improved and the fashion for wider tyres means there is so much more grip for cornering than in days gone by. However when conditions are bad the roads can be very slippery and, absent practice, that''s when accidents happen.

[michael769]

For example, completing all your braking in a straight line before turning into a corner. Are you really so close to the limit of traction at legal speeds that you're likely to skid off the road otherwise?

There are plenty of country roads where you cold easily skid off at 60 or less!

[GJD]

Are you really so close to the limit of traction at legal speeds that you're likely to skid off the road otherwise?

<snip>
However when conditions are bad the roads can be very slippery and, absent practice, that''s when accidents happen.

I think that's the point. It can't be a bad idea to be in command of a set of techniques that will serve you well on those occasions the gods conspire bring the limit of grip rather closer to you than normal.

[nightflight]

wrt using gears to slow, on my usual drive there's a steep hill which I'll turn into (tight 90 degree corner, usually having to stop to giveway to uphill traffic) at a crawling speed in 1st gear. I'll then cover the brake pedal and hold first gear all the way down the hill as the engine will happily (albeit noisly) rev up to 4500rpm whilst keeping me at a nice speed, then I've still got unfaded brakes ready to slow down for the T junction at the bottom of the hill.
Or should I be using my brakes for slow?

[Ancient]

That's using your engine (via the gears) to control and maintain your speed to an acceptable level. It is not using your gears to slow:

Slow:
Verb
Reduce one's speed or the speed of a vehicle or process.

[MGF]

It doesn't sound as though you are using the gears to slow but rather using them to stop you accelerating. That is the purpose of selecting a lower gear.

Edit - as above.