When to change gear on roundabouts?
Discussion
If I'm approaching a roundabout in 3rd gear (using engine braking) but need second to accelerate after exiting the roundabout should I change gear before, during or after using it, i.e. should I change to second then enter, change while about about halfway round (when turning radius is constant)or once the wheels are pointing straight after leaving. Sorry if this is an idiotic question as I'm only 17!
Thanks in advance
Thanks in advance
Syncromesh said:
If I'm approaching a roundabout in 3rd gear (using engine braking) but need second to accelerate after exiting the roundabout should I change gear before, during or after using it, i.e. should I change to second then enter, change while about about halfway round (when turning radius is constant)or once the wheels are pointing straight after leaving. Sorry if this is an idiotic question as I'm only 17!
Thanks in advance
Depends on you.Thanks in advance
The Black Flash said:
Not a stupid question at all.
Before, always. Then you are in the right gear for whatever may happen. That goes for pretty much any corner/hazard.
Cue heel'n'toe debate in 10...9...8...
The problem with doing it before though for me is that I feel I'm being mechanically unsympathetic if I change down to second at that sort of speed (about 25mph) and I don't want passengers to think I'm being 'boy-racer-ish' by unnecessary revving the engine. I also cannot heel'n'toe dut the pedal spacing in my car (although I do rev match if I'm not braking at the same time).Before, always. Then you are in the right gear for whatever may happen. That goes for pretty much any corner/hazard.
Cue heel'n'toe debate in 10...9...8...
usually it would be correct to take the gear before the hazard (roundabout) so - generally - if you will need 2nd for the exit, you need 2nd for the entry
but, on some bigger roundabouts, depending on quite how they are set up, there are circumstances where you would enter in 3rd (or higher) and find it necessary to take a lower gear on the roundabout (one with traffic signals for instance)
but, on some bigger roundabouts, depending on quite how they are set up, there are circumstances where you would enter in 3rd (or higher) and find it necessary to take a lower gear on the roundabout (one with traffic signals for instance)
vonhosen said:
Syncromesh said:
If I'm approaching a roundabout in 3rd gear (using engine braking) but need second to accelerate after exiting the roundabout should I change gear before, during or after using it, i.e. should I change to second then enter, change while about about halfway round (when turning radius is constant)or once the wheels are pointing straight after leaving. Sorry if this is an idiotic question as I'm only 17!
Thanks in advance
Depends on you.Thanks in advance
Fuel type, engine response and, related, gearing.
Syncromesh said:
If I'm approaching a roundabout in 3rd gear (using engine braking) but need second to accelerate after exiting the roundabout should I change gear before, during or after using it, i.e. should I change to second then enter, change while about about halfway round (when turning radius is constant)or once the wheels are pointing straight after leaving. Sorry if this is an idiotic question as I'm only 17!
Depending on the layout and size of the roundabout, your first or second suggestions could work.At what point are you at your lowest speed? The System (see Roadcraft) places the gear change after the speed change, and before the acceleration to leave the hazard.
If you change gear and then slow again, that's a clue that gear change might be in the wrong place.
HTH - there are (almost) no idiotic questions, just daft answers.
Better to ask than crash, I say. 
My short answer is - get into the gear you want for exiting the roundabout before you get onto the roundabout, gives you less to worry about. Long answer is below.
It does really depend a lot on the roundabout, the conditions, and the traffic. The important thing is to make sure to approach the roundabout at a speed that will allow you to stop safely and sensibly at the line if there is traffic on the roundabout. On some large roundabouts with good visibility you should be able to make sure the roundabout is clear quite early and travel through the roundabout with minimal speed loss. Other times you will need to keep slowing until you are sure there's a gap for you.
As regards when to change gear, There's no need to get down into 2nd above 20mph in most cars. If you do need to slow down that much to get into 2nd, the best time to change up again is when you are comfortable. This could be when you are in a lane on the roundabout, or it could be after you've straightened up on the exit. But generally if the car was providing engine braking at the entry speed to the roundabout, it'll be able to accelerate you out of the roundabout quite nicely in the gear it's in.
As for heel-and-toe, I've yet to drive anything with a manual box I haven't been able to do it in, and that includes vans, hatchbacks, and VAG cars with ludicrously overassisted brakes. And I only have size 8 feet. Some cars just need a quite unnatural rotation of the foot to get the heel onto the accelerator, which takes a fair bit of practice to do smoothly. It took me about 3 years to get to the point where I could do it properly, so don't worry too much.
My short answer is - get into the gear you want for exiting the roundabout before you get onto the roundabout, gives you less to worry about. Long answer is below.
It does really depend a lot on the roundabout, the conditions, and the traffic. The important thing is to make sure to approach the roundabout at a speed that will allow you to stop safely and sensibly at the line if there is traffic on the roundabout. On some large roundabouts with good visibility you should be able to make sure the roundabout is clear quite early and travel through the roundabout with minimal speed loss. Other times you will need to keep slowing until you are sure there's a gap for you.
As regards when to change gear, There's no need to get down into 2nd above 20mph in most cars. If you do need to slow down that much to get into 2nd, the best time to change up again is when you are comfortable. This could be when you are in a lane on the roundabout, or it could be after you've straightened up on the exit. But generally if the car was providing engine braking at the entry speed to the roundabout, it'll be able to accelerate you out of the roundabout quite nicely in the gear it's in.
As for heel-and-toe, I've yet to drive anything with a manual box I haven't been able to do it in, and that includes vans, hatchbacks, and VAG cars with ludicrously overassisted brakes. And I only have size 8 feet. Some cars just need a quite unnatural rotation of the foot to get the heel onto the accelerator, which takes a fair bit of practice to do smoothly. It took me about 3 years to get to the point where I could do it properly, so don't worry too much.
Edited by davepoth on Monday 4th October 01:26
WhoseGeneration said:
vonhosen said:
Syncromesh said:
If I'm approaching a roundabout in 3rd gear (using engine braking) but need second to accelerate after exiting the roundabout should I change gear before, during or after using it, i.e. should I change to second then enter, change while about about halfway round (when turning radius is constant)or once the wheels are pointing straight after leaving. Sorry if this is an idiotic question as I'm only 17!
Thanks in advance
Depends on you.Thanks in advance
Fuel type, engine response and, related, gearing.
There have been huge discussions about this in the past, so it's not a simple issue! 
Personally, my (hottly debated!) philosophy is to negotiate any hazard with both hands on the steering wheel, and free of any distractions such as gearchanges (I block the radio out, often stop conversations with passengers etc). Also, I like to keep the engine up at usable revs during the hazard as well, this is for reasons of stability during the cornering phase, and also if I need power to get out of trouble (for instance if a fast and previously unsighted car joins the roundabout suddenly to my right). As a result of this thinking, what I do is select the appropriate gear to negotiate the hazard (in this case a roundabout) beforehand. The OP mentioned feeling that the revs were too high for the appropriate gear at this stage. That shouldn't happen because the speed crossing the give way line should be the same as the roundabout negotiation speed for a totally clear sighted roundabout (that's just dynamic common sense; you'd take a clearly sighted S bend in the same way - steady throttle and constant speed), and proportionally lower as vision is restricted, which applies to the vast majority of roundabouts; so typically one will slow till one is sure the roundabout is clear, and then accelerate onto the roundabout.
The only time this doesn't work is if you have to come to a halt at the give way line, requiring first gear to pull away again, in which case a gearchange is often necessary during the roundabout. If that is the case, then I do so at what I feel is the safest point, based on vision primarily and dynamics second. Usually (but not always) this point is when the traffic to the right is almost certainly not going to join, but before the traffic on the left may join and require any braking or course corrections, and before the right hand corner of the roundabout. On small/mini roundabouts though I'll often hold onto first for the duration.
Personally, my (hottly debated!) philosophy is to negotiate any hazard with both hands on the steering wheel, and free of any distractions such as gearchanges (I block the radio out, often stop conversations with passengers etc). Also, I like to keep the engine up at usable revs during the hazard as well, this is for reasons of stability during the cornering phase, and also if I need power to get out of trouble (for instance if a fast and previously unsighted car joins the roundabout suddenly to my right). As a result of this thinking, what I do is select the appropriate gear to negotiate the hazard (in this case a roundabout) beforehand. The OP mentioned feeling that the revs were too high for the appropriate gear at this stage. That shouldn't happen because the speed crossing the give way line should be the same as the roundabout negotiation speed for a totally clear sighted roundabout (that's just dynamic common sense; you'd take a clearly sighted S bend in the same way - steady throttle and constant speed), and proportionally lower as vision is restricted, which applies to the vast majority of roundabouts; so typically one will slow till one is sure the roundabout is clear, and then accelerate onto the roundabout.
The only time this doesn't work is if you have to come to a halt at the give way line, requiring first gear to pull away again, in which case a gearchange is often necessary during the roundabout. If that is the case, then I do so at what I feel is the safest point, based on vision primarily and dynamics second. Usually (but not always) this point is when the traffic to the right is almost certainly not going to join, but before the traffic on the left may join and require any braking or course corrections, and before the right hand corner of the roundabout. On small/mini roundabouts though I'll often hold onto first for the duration.
Edited by RobM77 on Monday 4th October 11:44
Just for additional info here is a pic of the roundabout, bearing in mind the traffic levels are normally very low when I negotiate it, and I'm usually in the right hand lane as I have just overtaken someone, and need to be in the right hand land on the exit.
http://maps.google.co.uk/maps?hl=en&ie=UTF8&am...
Also, as I've only got a little 1.4 16v (so no low down grunt) pulling a reasonably heavy car for it's class (polo) 3rd gear just doesn't pull when under 3k, necessitating the exit in 2nd gear.
Unfortunately the car is a "VAG car with ludicrously overassisted brakes" so that makes heeling and toeing even harder (I used to do it no problem in my old mini) although I want to remaster it at some point.
http://maps.google.co.uk/maps?hl=en&ie=UTF8&am...
Also, as I've only got a little 1.4 16v (so no low down grunt) pulling a reasonably heavy car for it's class (polo) 3rd gear just doesn't pull when under 3k, necessitating the exit in 2nd gear.
Unfortunately the car is a "VAG car with ludicrously overassisted brakes" so that makes heeling and toeing even harder (I used to do it no problem in my old mini) although I want to remaster it at some point.
Syncromesh said:
Just for additional info here is a pic of the roundabout, bearing in mind the traffic levels are normally very low when I negotiate it, and I'm usually in the right hand lane as I have just overtaken someone, and need to be in the right hand land on the exit.
http://maps.google.co.uk/maps?hl=en&ie=UTF8&am...
Also, as I've only got a little 1.4 16v (so no low down grunt) pulling a reasonably heavy car for it's class (polo) 3rd gear just doesn't pull when under 3k, necessitating the exit in 2nd gear.
Unfortunately the car is a "VAG car with ludicrously overassisted brakes" so that makes heeling and toeing even harder (I used to do it no problem in my old mini) although I want to remaster it at some point.
Heel and toe shouldn't be necessary if following my routine as described above. I heel and toe quite a lot in both my cars, but this is one situation where I wouldn't; I'd be down to the appropriate speed before the junction, then select the appropriate gear using a rev match off the brakes before negotiating the roundabout at that same steady speed.http://maps.google.co.uk/maps?hl=en&ie=UTF8&am...
Also, as I've only got a little 1.4 16v (so no low down grunt) pulling a reasonably heavy car for it's class (polo) 3rd gear just doesn't pull when under 3k, necessitating the exit in 2nd gear.
Unfortunately the car is a "VAG car with ludicrously overassisted brakes" so that makes heeling and toeing even harder (I used to do it no problem in my old mini) although I want to remaster it at some point.
Edited by RobM77 on Monday 4th October 17:18
I agree with all the advice above to the effect that one should enter a roundabout, bend or junction at the correct speed and in the correct gear for the speed...drive through (maintaining balance and smoothness) and accelerate out by 'squeezing' the power on when the wheels are straight!!
When steering is being applied both hands need to be on the wheel........lets call it 'best practise'
........ I know plenty who drive everywhere with one hand resting at the bottom of the wheel!!
A
When steering is being applied both hands need to be on the wheel........lets call it 'best practise'
........ I know plenty who drive everywhere with one hand resting at the bottom of the wheel!!A
On a small roundabout like that, I'd be surprised if there were circumstances where I was entering and exiting in different gears...
If I needed 2nd for the exit, then - if my place on the roundabout was available as I approach - I'd be slowed down, off the brakes and taking 2nd about 1 artic truck length before the roundabout. I'd hold that speed (which would need a bit of gas adding to help with stability and control as the steering is put in) to the 'apex' of the roundabout and start to think about accelerating back up towards 50 as I unwound the steering.
Just to add to the fun, you could block change down on the approach and block change back up again after the exit - some observers would really like that!
If I needed 2nd for the exit, then - if my place on the roundabout was available as I approach - I'd be slowed down, off the brakes and taking 2nd about 1 artic truck length before the roundabout. I'd hold that speed (which would need a bit of gas adding to help with stability and control as the steering is put in) to the 'apex' of the roundabout and start to think about accelerating back up towards 50 as I unwound the steering.
Just to add to the fun, you could block change down on the approach and block change back up again after the exit - some observers would really like that!
ClassOne said:
I agree with all the advice above to the effect that one should enter a roundabout, bend or junction at the correct speed and in the correct gear for the speed...drive through (maintaining balance and smoothness) and accelerate out by 'squeezing' the power on when the wheels are straight!!
When steering is being applied both hands need to be on the wheel........lets call it 'best practise' ........ I know plenty who drive everywhere with one hand resting at the bottom of the wheel!!
A
Thanks When steering is being applied both hands need to be on the wheel........lets call it 'best practise'
........ I know plenty who drive everywhere with one hand resting at the bottom of the wheel!!A
Although I should add that adding power when the wheels are straight is not maintaining balance and smoothness A small point, but I couldn't resist pointing that out!You are asking on the Advanced Driving Forum. The conventional advanced driving approach to this question is: 'Slow until you know, take the gear and go'. Put differently, slow down for the roundabout in whatever gear you happen to be in, do not change down unless you need to pick up the drive at a speed at which the car would struggle in the gear you are in, wait until you know what gear you are going to need to drive out of the hazard, then make a single gear change to whichever gear that is.
Applying this to a roundabout, do not change gear at all until you know whether you can or cannot go, then go straight to the appropriate gear (1st, 2nd or 3rd). You will often make the decision, finish braking, take the gear and pick up the drive before entering the roundabout. If however, perhaps due to a late view to the right, this system results in finishing the gearchange as you enter the roundabout that is no problem. If you find you have to press the clutch to prevent the engine from labouring as you slow, but before you are ready to go, again that is no problem. If you are keeping the car under control using the brakes a brief period of coasting is acceptable.
This approach to changing gear at a roundabout is different from what most driving instructors teach; driving instructors are likely to teach you to change down to second gear while you are still braking, not because it is a better system but because it is easier for new drivers. Advanced drivers do not generally change gear and brake at the same time unless they have developed the skill to heel and toe (operate accelerator and brake at the same time). Advanced drivers invariably rev match when they change down, applying an appropriate amount of acceleration, for smoothness and mechanical sympathy.
Applying this to a roundabout, do not change gear at all until you know whether you can or cannot go, then go straight to the appropriate gear (1st, 2nd or 3rd). You will often make the decision, finish braking, take the gear and pick up the drive before entering the roundabout. If however, perhaps due to a late view to the right, this system results in finishing the gearchange as you enter the roundabout that is no problem. If you find you have to press the clutch to prevent the engine from labouring as you slow, but before you are ready to go, again that is no problem. If you are keeping the car under control using the brakes a brief period of coasting is acceptable.
This approach to changing gear at a roundabout is different from what most driving instructors teach; driving instructors are likely to teach you to change down to second gear while you are still braking, not because it is a better system but because it is easier for new drivers. Advanced drivers do not generally change gear and brake at the same time unless they have developed the skill to heel and toe (operate accelerator and brake at the same time). Advanced drivers invariably rev match when they change down, applying an appropriate amount of acceleration, for smoothness and mechanical sympathy.
Syncromesh said:
That makes it a bit easier - it's two minutes from my house and I drive it regularly. It's difficult because it's a fairly tight roundabout at the end of a fast-ish straight, and I can see why you're wanting to exit in second gear.The answer to your question is to brake firmly enough so that you could stop at the entrance to the roundabout. When you're quite close to the line you'll be able to see if anyone coming down Cribbs Causeway is going to block you, and if it's clear then you take second and enter the roundabout.
Getting the speed down early enough is something that takes a lot of practice, but it's the only way to negotiate this particular roundabout.
Syncromesh said:
...need to be in the right hand land on the exit.
No you don't, unless you're immediately going to overtake again. You should almost certainly be in the nearside lane, possibly moving into lane two to pass the Shell station if there's activity on the forecourt.I'm sure you're not the problem, but people who take up the outside lane because they're turning right sometime later that day are all over Bristol, and it really winds me up.
S. Gonzales Esq. said:
Syncromesh said:
That makes it a bit easier - it's two minutes from my house and I drive it regularly. It's difficult because it's a fairly tight roundabout at the end of a fast-ish straight, and I can see why you're wanting to exit in second gear.The answer to your question is to brake firmly enough so that you could stop at the entrance to the roundabout. When you're quite close to the line you'll be able to see if anyone coming down Cribbs Causeway is going to block you, and if it's clear then you take second and enter the roundabout.
Getting the speed down early enough is something that takes a lot of practice, but it's the only way to negotiate this particular roundabout.
Syncromesh said:
...need to be in the right hand land on the exit.
No you don't, unless you're immediately going to overtake again. You should almost certainly be in the nearside lane, possibly moving into lane two to pass the Shell station if there's activity on the forecourt.I'm sure you're not the problem, but people who take up the outside lane because they're turning right sometime later that day are all over Bristol, and it really winds me up.
The consensus seems to be to change down before entering the roundabout so that is what I shall practise from now on. As some of suggest I think I shall adopt the method of braking earlier in third, then rev-match changing to second, then checking my entrance, then keeping a constant speed (about 20mph I'd guess) through the the roundabout, then accelerating once straight.
I don't entirely see why you need to be in lane 2 if traffic is very light. I'd expect to take either lane 1 or straightline it. Either way it's brakes to slow gear to go, and with good vision that will happen at or just before the line.
I don't see how taking L2 improves the 'braking zone'.
I don't see how taking L2 improves the 'braking zone'.
Edited by Z.B on Monday 4th October 21:10
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