BGOL, Block Shifting, and Sequential Gears

[SammyTheSnake]

Hi, all. This is the first of my posts asking questions that have occurred to me as I've read through this forum and which I hope will be answered and stimulate helpful discussion!

Today's question is a bit nebulous, but I'm trying to work through what the implications for me as a motorcyclist are of the ideas of block shifting and Brake/Gear Separation.

My normal riding style (which I expect will change as I integrate more of what I've been reading here!) on approach to a corner or junction goes something like this:

1) Get into the right road position
2) Release the throttle to begin slowing
3) Possibly change gear, depending on whether the corner requires a lower gear than I'm in
4) Further use of engine braking, now that I'm in a lower gear
5) Possibly further gear changes if I'm coming from high speed into a tight corner
6) As I near the corner/junction, use brakes if necessary to reduce speed further
7) turn in, possible overlapping with the last bit of braking

Now, I can definitely see the benefit of avoiding changing gear in a corner (though I'll still do it on occasion with care) and I can see the benefit of getting all (or at the very least the majority) of braking done before turn-in. I can see the benefit in terms of brake lights for following traffic of using the brakes earlier rather than later, and not relying too much on engine braking.

I'm certainly not claiming that the system I've instinctively developed is the best (and I can see holes in it) but I'm just relating what I usually find myself doing.

The main bit I'm struggling with is this

Block changing: If I leave all my gear changing until the last thing on my list before the corner, I still have to go through all the intermediate gears in order to get to whatever gear I want to be in (sequential gearbox and all that) so I don't see that block shifting can offer me anything, and given that I feel it's apropriate to actually make use of the intermediate gears I have to go through anyway. What do people think?

There are other things, (I'm sure people will take note of my use of engine braking, for example) but I think that's the one that's really quite bike-specific, so I'll post the others in separate threads in the general forum.

Thanks in advance for the replies which I expect to be of high quality!

Cheers & God bless
Sam "SammyTheSnake" Penny

[BillZZR600]

Thanks in advance for the replies which I expect to be of high quality!

Nothing like expectations of quality. LOL

I am at work at the moment, and about to head home, so I will attempt to answer and or agree some of your points later when I am able, assuming the very high quality Mr RMR doesnt get to you first

In the mean time can you answer me a qualifying question.

In general when riding along a sc NSL road, at or around the 60 limit, what gear do you usually find yourself using?

[SammyTheSnake]

Thanks in advance for the replies which I expect to be of high quality!

Nothing like expectations of quality. LOL

I am at work at the moment, and about to head home, so I will attempt to answer and or agree some of your points later when I am able, assuming the very high quality Mr RMR doesnt get to you first

In the mean time can you answer me a qualifying question.

In general when riding along a sc NSL road, at or around the 60 limit, what gear do you usually find yourself using?

Well, my high expectations are built solely on the preceeding quality, so I don't think they're unreasonable

I generally pootle along in top gear unless there's a particular cause to be in a lower gear. I probably tend to use too high a gear in most circumstances to save petrol, but also because changing speed gently is nice and easy in a high gear where I don't have oodles of spare power / engine braking.

I've been gently increasing my use of lower gears because of the higher control available and because, as my confidence grows, I'm looking to be more progressive, particularly in terms of accelerating out of corners.

One of the things that took me a long time to get anything like a grip on is just how much traction my nice bridgestone tyres afford me. I know the bike will lean over to damn-near 45 degrees, that it has enough grip on the (brand new and not worn in yet) rear tyre to pull a wheelie in standing water levels of rain, but somehow it feels like a different thing to trust that grip while leaning *and* accelerating/braking. I don't want to find where that grip extends to by exceeding it wholesale!

So, in answer to the question you actually asked, 6th (from six) is my normal gear for SC/60 roads, unless I'm negotiating a corner or other hazard.

Cheers & God bless
Sam "SammyTheSnake" Penny

[BillZZR600]

I generally pootle along in top [6th] gear unless there's a particular cause to be in a lower gear. I probably tend to use too high a gear in most circumstances to save petrol, but also because changing speed gently is nice and easy in a high gear where I don't have oodles of spare power / engine braking.

Well this sort of points to the answers to your own question .

With little or no engine braking when shutting the throttle, you are having to use the brakes more, to loose speed, (probably compressing the front forks and transferring too much weight forward and off the rear driving wheel) but at the same time as you loose that speed you will find that you are in a Very wrong gear to gently power (balanced) through the bend and accelerate away from it.
This will necessitate furtherrushed downshifts, which because your engine speed is already low will require great care and or multiple changes to avoid locking up (even momentarily) the rear wheel, further destabelising your machine.

But ultimately I suspect you will either end up entering the bend too fast and trail braking into it, or almost coasting without power and unable to follow a controlled line.

Try running in a much more responsive gear (this will vary machine to machine)on your Divvy600 say 3rd or 4th for those kind of speeds (My own in 3rd runs at approx 30mph at 3000rpm and 60 at 6000 with a redline of over1200!!!) with plenty of engine braking but also with almost instant power available on light throttle openings. this will mean that you have much more time to

1 get your info on the bend.
2 adjust if necessary your positioning
3 reduce your speed (if necessary) by more effective engine braking/and gentle use of brakes (Gently OFF BRAKES BEFORE YOU TURN IN)
4 if needed, Select an apropriate lower responsive gear for your speed, on 1 change (or if needed a double downshift with either a bliped throttle or sustained revschange, (and slip out, not dump the clutch)
5 On a gently opened to fixd throttle, hold the line and drive through the bend, only opening up as the bike comes more upright as the bend opens and away you go into the powerband, without having to change mid corner.

[7db]

Incidentally, my understanding of fuel consumption is that it makes nearly no difference which gear you are in. The thing that affects fuel consumption most is how much braking you end up doing over the course of a journey. Do all your slowing on acceleration sense alone and watch the fuel economy soar.

[BillZZR600]

Incidentally, my understanding of fuel consumption is that it makes nearly no difference which gear you are in. The thing that affects fuel consumption most is how much braking you end up doing over the course of a journey. Do all your slowing on acceleration sense alone and watch the fuel economy soar.

I agree, braking and then rolling open the throttle in too High (number) a gear with the engine drinking fuel and labouring to climb back into the powerband.

[BillZZR600]

Oh and Sam,
yes unlike a car you do indeed have a sequential gearbox therefore technically you cannot Block Change and go from 5th to 2nd without going through the intermediates (whether you actually engage the drivetrain or not) but the secret which all us bikers strive for is to be in the gear, one above, or one below the one we are actually about to need.

[SammyTheSnake]

Incidentally, my understanding of fuel consumption is that it makes nearly no difference which gear you are in. The thing that affects fuel consumption most is how much braking you end up doing over the course of a journey. Do all your slowing on acceleration sense alone and watch the fuel economy soar.

I don't see how that would work :-S

I'm sure the reason people say "braking is what increases your fuel consumption" is that you have to speed up again afterwards, which uses fuel.

In terms of fuel consumption in different gears, you will certainly use more fuel in a lower gear because for each rotation of the driving wheel (or mile of ground covered or whatever) you have more rotations of the engine, each of which will involve an ignition/power phase in half the cylinders (assuming a 4 stroke engine) complete with a cylinder full of fuel/air mix.

On the other hand, there's more fuel in the cylinder for each ignition/power phase when you're accelerating than when you're using the engine for engine braking (that's *why* you accelerate / decelerate) but if you were slowing down using the brakes (with the clutch disengaged and the engine idling or even off) you'd be using even *less* fuel during deceleration.

When it comes to acceleration again, the factors that affect your fuel consumption (choice of gear, speed you're accelerating from/to, how firmly you choose to accelerate) are nothing to do with how you reached the lower speed you're accelerating from...

If anyone can point out where this logic is flawed (and I'm sure to have missed something!) do tell

Of course, once F1 (and subsequently, road vehicles) start using brakes that store the kinetic energy they currently dissipate as heat and provide that for accelerating, the difference made by speed changing (in either direction) to fuel consumption will drop considerably...

Cheers & God bless
Sam "SammyTheSnake" Penny

[SammyTheSnake]

Thanks, Bill, for a thoughtful response

I'm not arguing in the following that the system is in any way wrong, I'm just trying to understand how I ought to apply it and *how* it's an improvement over my current style :-p (I appreciate that I often come accross a little more confrontational than I mean to, so please forgive me if I manage to sound off :-p)

I generally pootle along in top [6th] gear unless there's a particular cause to be in a lower gear. I probably tend to use too high a gear in most circumstances to save petrol, but also because changing speed gently is nice and easy in a high gear where I don't have oodles of spare power / engine braking.

Well this sort of points to the answers to your own question .

With little or no engine braking when shutting the throttle, you are having to use the brakes more, to loose speed, (probably compressing the front forks and transferring too much weight forward and off the rear driving wheel) but at the same time as you loose that speed you will find that you are in a Very wrong gear to gently power (balanced) through the bend and accelerate away from it.
This will necessitate furtherrushed downshifts,

Trying to follow you here, but I'm not sure your description matches up with what I think is happening for me, let me have another go and see if that helps :-p

I'm changing gear *before* braking, slowing down well in advance of the corner to what I could call "approach speed" changing down as I slow (begining to use more engine braking as I'm in lower gears) using brakes only for the last bit of slowing.

I don't think "having to use the brakes more" really fits what I'm doing, perhaps "slowing down sooner to avoid having to use lots of brakes" would match more?

Again, I'm changing gear *before* braking (well, maybe one last gear change if I'm coming down lots of gears (e.g. a tight corner on an otherwise faster road, or approaching a junction from a high-gear situation) and I don't feel any of my gear changes are rushed. Indeed, I could hapily change from 6th to 1st in less than a second, providing my synchromesh allows me to!

which because your engine speed is already low will require great care and or multiple changes to avoid locking up (even momentarily) the rear wheel, further destabelising your machine.

Changing down to a much lower gear than I'm approaching the gear change in would potentially cause loss of traction, but in that scenario, I'd raise the engine speed and/or use lots of clutch. I've not actually had this happen to me more than twice since I started riding motorcycles, and one was during a lesson. (The other time was when a car driver cut me up rather severely on a sharp 2-lane corner and I didn't handle it with the panache I hope to achieve!)

But ultimately I suspect you will either end up entering the bend too fast and trail braking into it, or almost coasting without power and unable to follow a controlled line.

Trail braking might fairly describe my braking at times, but when I am still braking when I start turning in, it's usually because I'm too impatient to slow down *that* much before turn-in rather than because I've run out of time to do so. In terms of being in too-high a gear in the corner, I probably choose higher gears than some would, but I am usually in the gear I want to be in (again, I'm not perfect, but with only 3 years' experience behind me, I expect I'll still be improving when it's 30 or more!) In terms of not being able to control my line, I've not really found that to be a problem, though I am trying to spend more time in lower gears, particularly in corners in order to improve the control I have. It takes practice, though!

Try running in a much more responsive gear (this will vary machine to machine)on your Divvy600 say 3rd or 4th for those kind of speeds (My own in 3rd runs at approx 30mph at 3000rpm and 60 at 6000 with a redline of over1200!!!) with plenty of engine braking but also with almost instant power available on light throttle openings. this will mean that you have much more time to

I get that gearing ratio in 4th, but my redline is lower than yours, so I suppose if we normalised it to account for that, 3rd would be about equivalent.

I suppose one way of looking at it is that at some point before the corner, I switch into that "more responsive gear" then closer to the corner change down again in much the way anyone else would.

1 get your info on the bend.
2 adjust if necessary your positioning
3 reduce your speed (if necessary) by more effective engine braking/and gentle use of brakes (Gently OFF BRAKES BEFORE YOU TURN IN)
4 if needed, Select an apropriate lower responsive gear for your speed, on 1 change (or if needed a double downshift with either a bliped throttle or sustained revschange, (and slip out, not dump the clutch)
5 On a gently opened to fixd throttle, hold the line and drive through the bend, only opening up as the bike comes more upright as the bend opens and away you go into the powerband, without having to change mid corner.

I think what I do matches pretty well with that description, actually, except that I'd add:

2.5: change from "pootling gear" to "engine braking gear"

and I probably brake later than I "ought to" which is a bad habit I intend to change :-p

Then...

Oh and Sam,
yes unlike a car you do indeed have a sequential gearbox therefore technically you cannot Block Change and go from 5th to 2nd without going through the intermediates (whether you actually engage the drivetrain or not) but the secret which all us bikers strive for is to be in the gear, one above, or one below the one we are actually about to need.

I think that inevitably means more gear changes, though, unless we want to compromise the choice of gear in the previous situation (straight approaching a hazard, or even possibly the previous hazard) i.e. the gear I want to be in *now* just isn't the gear 1 up or 1 down from the gear I want to be in next, so I have to either be in the "wrong" gear now or make two (or more!) gear changes before I get to the point where I want to be in that new gear.

Given that a change in gear will usually be accompanied by a change in speed, which takes time, I usually find there's plenty of time to do those gear changes one at a time. There are obviously some situations where that's not quite the case, e.g. following a slow car in a place where there's just no place to overtake (lots of oncoming traffic perhaps) then I'll want to be "pootling" until the next chance to overtake approaches, then either get into an intermediate lower gear to follow the car and make another gear change to actually overtake, or maybe make a double gear change at a later point in the maneouvre (I'd favour the first, usually)

Cheers & God bless
Sam "SammyTheSnake" Penny

[SammyTheSnake]

Three posts in a row in one thread, sorry!

Just a note to say my copy of "Motorcycle Roadcraft" has just arrived and I'm reading through it. First glance is very encouraging, so I'll come back to this thread when I've read the relevant sections of the book!

Cheers & God bless
Sam "SammyTheSnake" Penny

[BillZZR600]

Three posts in a row in one thread, sorry!

Just a note to say my copy of "Motorcycle Roadcraft" has just arrived and I'm reading through it. First glance is very encouraging, so I'll come back to this thread when I've read the relevant sections of the book!

Cheers & God bless
Sam "SammyTheSnake" Penny

Well we got your system from 7 points down to you agreeing to 5.5 so maybe Roadcraft can show you with diagrams why there are 5. [JOKE]

But seriously have a look at the section on tyre grip trade off and machine balance in cornering, and you will see why it is usually advocated that you complete any braking/speed reduction well before the turn (point three in the 5 point "system") before selecting the apropriate gear (point four)

tip: you may already be in it if you have allready got your speed right in a responsive gear for negotiating (and exiting) the bend or hazard

But like I say to everyone who gets a copy of roadcraft, its a
1:Read it
2:Try,it ( go back to stage one and repeat)
3:Do it

and unless you suffer from insomnia and looking for a non ingested cure, NOT bedtime reading

Phew thats me off the hook.

PS you dont have synchromesh on your Bike gearbox

[SammyTheSnake]

have a look at the section on tyre grip trade off and machine balance in cornering, and you will see why it is usually advocated that you complete any braking/speed reduction well before the turn (point three in the 5 point "system") before selecting the apropriate gear (point four)

tip: you may already be in it if you have allready got your speed right in a responsive gear for negotiating (and exiting) the bend or hazard

I do see the logic of avoiding trail braking, it just seems so tempting to maintain the speed for that extra few feet. I'm a firm believer in giving something a go and letting it grow on you, though, which is what I'm doing :-p

My car driving instructor suggested I held the gearstick differently and having been unconvinced but trying it anyway, I now use his method. I'm not convinced on the block-shifting yet, but I'm still trying it :-p

But like I say to everyone who gets a copy of roadcraft, its a
1:Read it
2:Try,it ( go back to stage one and repeat)
3:Do it

Agreed, I'm still reading through it, though, it's a substantial book, not so much lots of words as lots of stuff to think about. I'm still in the visualising stage at the moment, but when I next go out on the bike I'll be trying to apply a few bits. Not too much at once, though...

and unless you suffer from insomnia and looking for a non ingested cure, NOT bedtime reading

Heh, I read more in bed than any other time (well, maybe on the loo is a contender for favourite reading spot, too...)

PS you dont have synchromesh on your Bike gearbox

Oh dear, maybe that's why my gearbox is starting to sound like a bucket of gravel

Seriously, though, *something* stops me changing into low gears at high speeds (particularly noticable into first) and seems to do a pretty good job of clutchless gearshifts. Is there some other doohicky that takes charge of that? I'm not massively good on my understanding of gearboxes, it's difficult to find comprehensive but clear information about them Maybe I'll have a go at servicing mine when it needs it

Cheers & God bless
Sam "SammyTheSnake" Penny

[7db]

I do see the logic of avoiding trail braking, it just seems so tempting to maintain the speed for that extra few feet.

I'd like to take you through my thoughts on the "last few feet" fallacy...put simply it's that the benefit of a tiny amount of extra speed for a tiny amount of extra distance is nothing compared to being on the gas earlier.

It is a characteristic of the vehicle that it brakes harder than it acclerates, so by leaving the braking later, you save a tiny amount of time compared with getting the power on earlier. So anything which means is it more likely that you will be fully on the gas at exit later will lose you time through the corner. If vehicles accelerated harder than they braked, we'd all be going around saying "fast in, slow out". They don't. I wish I had Von's artistic ability and could draw you the speed/time graph.

Typically the limit in a corner is vision, then confidence, then grip.

The extra few mph at entry set the corner up all wrong. They make it less likely that you will drive on vision, and increase the liklihood that you'll lose confidence (and lift). The grip is secondary to these two factors (as it is less likely to be limiting), but is as Bill points out *slightly* reduced by braking.

And in writing this, I've just had a huge insight into apexing in the velocity space, which I'll have to go and write down somewhere else.

Anyway, suffice to say, it is far far far better (quicker, safer) to enter a corner slower than the maximum speed, on the gas and powering through it as vision opens up, that to be entering on the limit of confidence and wallowing out of it.