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Downshifting gears


Guest henryg

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Maybe it just wasn't disengaging fully Rocker? It's deffo the reason on wet clutches though.

You'll need only a tiny difference in movement between the dogs to cause a clunk.

In any event, it's generally a non issue.

Edited by sid
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I found the following improved my gearshifting dramatically. They became smoother, more efficient and faster than I could ever have previously hoped to achieve. Step 1: Got a DCT Step 2 (opt

This thread is teetering on the abyss, oil already mentioned and we'll be onto the California race blokes run in by 20 miles at full throttle any second now!     The thing will all such info

Auto blippers are fun! Then, after about 10 miles, become boring..     They’re part of the ‘performance obsession’ that create road bikes that would have won a Moto GP race ten years ago and

Rocker66
25 minutes ago, sid said:

Maybe it just wasn't disengaging fully Rocker? It's deffo the reason on wet clutches though.

You'll need only a tiny difference in movement between the dogs to cause a clunk.

In any event, it's generally a non issue.

Well I don’t think that could have been the reason as most of the time it was quiet well other than the typical Ducati dry clutch rattle.

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I like a good clunk into 1st. It's the sound of victory!

 

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Don't know then Rocker on yours.

Never owned or worked on a bike with a dry clutch.

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Rocker66
25 minutes ago, sid said:

Don't know then Rocker on yours.

Never owned or worked on a bike with a dry clutch.

You don’t know what you have missed 😀😀

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2 hours ago, sid said:

 Old thread, but I don't think this got answered?

 

It's basically down to the wet clutch. Even though the clutch is pulled in (disengaged) the oil moving / spinning around acts almost like a torque converter on the clutch.

Although the output is stationary, the input shaft will still be spinning slightly. When you put it in first, you have non moving dogs meeting slightly spinning dog slots - hence the clunk.

All perfectly normal. If the clunk is really excessive it may just be clutch drag and you need to adjust the cable to reduce the effect.

Sometimes it helps to keep the clutch pulled in for an extra few seconds, as the plates will separate fully and the torque converter effect is less severe.

 

Hope that makes sense?

 

Yeah, I can see that. The worst example I had was on one of the early Hinckley 900 triples. The first clunk into gear on a cold engine would stall it. I took to starting it on the centre stand with first gear engaged and then lifting the clutch and jabbing the rear brake. Unacceptable.

 

Triumph, at that time, recommended Mobil 1 oil and an American journalist (whose name I have forgotten, sadly) did a piece on how the gear selection of his own 900 had been much improved by a switch to Castrol.

 

 I tried Castrol and damned if he wasn’t right! Hardly any clunk from cold and never even close to bad enough to stall the motor. The dry (single plate) clutches on my boxers and Guzzis never clunked. Engagement of first was so silent it was sometimes difficult to know if it had actually gone into gear at all.

 

Thanks for the answer. 

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Hickky

All those who only use the brakes to slow down and don't use the gearbox/engine braking, you're wrong! Perhaps if you have a 2 stroke where there is little engine braking you could have a case (although a nice wing,wiiiing from a 2 stroke is music to some) but slowing down without the front diving under braking to be in the correct gear is safer! Maybe Roadcraft was written when the Police rode Scott bikes or BSA bantams.  Bliping the throttle on the downshift is also the correct thing to do, why else are more and more bikes sold with auto blippers/quickshifters? Because these skills (I also double de-clutch a manual car) are not taught in CBT is one reason I guess!

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embee
12 hours ago, Tex said:

 

....on how the gear selection of his own 900 had been much improved by a switch to Castrol.

 

 I tried Castrol and damned if he wasn’t right! Hardly any clunk from cold …….

That's one reason why I use Castrol Power1 in my bikes, from cold the clutch stick seems to be significantly less than with some other oils (I haven't tried all available oils so can't say it's the best …….)

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embee
8 hours ago, Hickky said:

All those who only use the brakes to slow down and don't use the gearbox/engine braking, you're wrong! Perhaps if you have a 2 stroke where there is little engine braking you could have a case (although a nice wing,wiiiing from a 2 stroke is music to some) but slowing down without the front diving under braking to be in the correct gear is safer! Maybe Roadcraft was written when the Police rode Scott bikes or BSA bantams.  Bliping the throttle on the downshift is also the correct thing to do, why else are more and more bikes sold with auto blippers/quickshifters? Because these skills (I also double de-clutch a manual car) are not taught in CBT is one reason I guess!

Pretty much agree. Absolutely nothing wrong using engine braking for slowing down, it goes with planning ahead etc. I agree that you shouldn't really use the CLUTCH for slowing down, which is why I'm also a blipper (on the manual bikes) on downshifts, minimise the wear and tear on the clutch and also it gives me a warm feeling. ;)

As for the Roadcraft dogma, I still think the one about keeping the back brake on when stationary (hence the "Hendon shuffle") dates from when the brake light was only operated by the rear brake, there was no front brake switch on most bikes until the 1970s. Maybe that dogma has changed now and it's accepted that you can hold on the front. Using the rear does make it easier to do uphill starts, but use whatever is appropriate for the circumstances rather than stick to one hard and fast "one size fits all" rule.

Many bikes from the 60s and earlier had the same brake front and back, and unless you used both you stood no chance of actually stopping. I had a BSA A7 with a 7" single leading sponge at both ends, absolutely useless thing.

Edited by embee
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Grumpy old man
5 hours ago, embee said:

That's one reason why I use Castrol Power1 in my bikes, from cold the clutch stick seems to be significantly less than with some other oils (I haven't tried all available oils so can't say it's the best …….)

Now I'm sure you have told us before, it's NOT  the Castrol Power 1 RACING oil, is it? I'll try it next oil change. Thanks

Edited by Grumpy old man
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embee
2 minutes ago, Grumpy old man said:

Now I'm sure you have told us before, it's NOT  the Castrol Power 1 racing oil, is it? I'll try it next oil change. Thanks

I use the semi-synth "regular" Power1, but the racing synthetic version may well act the same, I don't know, I've never tried it.

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On 3/27/2019 at 18:49, henryg said:

... Pretty convinced it is not the bike but me!  ...

It takes a proud and noble man to admit this, well done!

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Think I may try that Castrol on the next oil change tbh.

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embee

I don't want to over-sell Castrol oils, you may well find opinions to the contrary elsewhere (I use Mobil in the car :lol: ).

I tend to get mine from https://www.opieoils.co.uk/ when they have offers on (discounts and/or free p&p, sign up to emails and they'll send you the offers, there's a £10 off £50 for Easter now but watch the p&p). I have no commercial connection, just a customer. They also have a shop on the auction site and quite often it works out cheaper there with p&p, especially if you get an auction site discount code to use, which seems more common now.

Edited by embee
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16 hours ago, embee said:

I use the semi-synth "regular" Power1, but the racing synthetic version may well act the same, I don't know, I've never tried it.

 

I use that in the Bonnie and the Street Triple. Excellent clutch performance and a pretty red colour. Winner! 

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Rev Ken
On 21/04/2019 at 01:24, Hickky said:

All those who only use the brakes to slow down and don't use the gearbox/engine braking, you're wrong! Perhaps if you have a 2 stroke where there is little engine braking you could have a case (although a nice wing,wiiiing from a 2 stroke is music to some) but slowing down without the front diving under braking to be in the correct gear is safer! Maybe Roadcraft was written when the Police rode Scott bikes or BSA bantams.  Bliping the throttle on the downshift is also the correct thing to do, why else are more and more bikes sold with auto blippers/quickshifters? Because these skills (I also double de-clutch a manual car) are not taught in CBT is one reason I guess!

It isn't only Police Road craft (which incidentally is updated frequently - I've got two versions in the last few years. All authorised driving instructors teach drivers to slow using the brakes, and then  - but only then - to change to the appropriate gear (block change on bikes). I guess my 'heel and toe' braking and gear changing on my Boxster might not pass the IAM RoadSmart or RoSPA advanced driving test!

 

Before disc brakes we often needed all the help we could get to stop, hence the use of gears was 'normal'. Old habits die hard and I doubt I'll change now.

 

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SteveThackery

I think it's important to remember that the two basic approaches aren't mutually exclusive.  I use both.

When I know I'm going to stop (because I've seen the lights change, for instance) then I slow down with the brakes, leaving the bike in the same gear.  Before coming to a halt - at perhaps 10-15mph? - I pull in the clutch and "block shift" through the gears to neutral as I come to a halt.  It's much easier - and less annoying for everyone else - than going: blip-change....... blip-change......... blip-change........ down through the box just to come to a halt.

When I'm slowing down but don't know whether I'll be stopping or accelerating away (approaching a roundabout, for instance) then I slow down with the brakes, but also change down the gearbox one gear at a time, as appropriate, so that I can accelerate away comfortably at any moment.

 

In neither case do I actually slow down with the gears (i.e. change to a low gear and use engine drag as part of my braking strategy).  I think it's pointless, prone to giving a jerky ride, and possibly increases wear and tear (although that's a weak argument).  It's important to emphasise that changing down through the gears so you are ready to accelerate away is not the same as changing down the gears to make use of the increase drag from the engine as a brake supplement.

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Hickky
3 hours ago, SteveThackery said:

 

 

In neither case do I actually slow down with the gears (i.e. change to a low gear and use engine drag as part of my braking strategy).  I think it's pointless, prone to giving a jerky ride, and possibly increases wear and tear (although that's a weak argument).  It's important to emphasise that changing down through the gears so you are ready to accelerate away is not the same as changing down the gears to make use of the increase drag from the engine as a brake supplement.

I guess some of this is about the amount of drag from the engine your machine will give you. However, the reliance of just the brakes to slow down must promote some instability to the machine, particularly with telescopic front forks, placing increased stress on the front tyre, where the unexpected loss of adhesion can lead to all sorts of issues.

The first lesson given on the California Racing school is going around the circuit without using your brakes. You can only achieve this by using engine braking and changing down smoothly by blipping the throttle on down changing. This lesson is to give the racers the skills to be in the right gear for every corner. This promotes your ability to keep the machine stabilised at all times. Obviously, later on, the use of hard braking, combined with down shifting, and use of the engine to slow down is taught, but only after the skills of keeping the machine in balance are acquired.

Contrary to some peoples opinion, wear and tear is reduced if the blipping/down shifting is done with some skill, as it places less stress on the gear dogs on the initial take up, and less forces on the clutch. The engine too has opposite forces placed on it that keeps stresses balanced.

I have recently had to have the brake pads on my car changed after 62,000 miles on the O/E ones, It is an automatic with flappy paddles which are used for changing down where i am on a twisty road. No longer can I double de clutch, but I can keep the vehicle in balance and be in the correct gear for the road conditions. The vehicle (an automated manual) auto blips the engine on downshifting. At 72,000 miles the clutch shows little signs of wear.

Therefore, Steve, skilled blipping promotes a smoother ride if done skilfully. Arriving at a corner in front of you, braking, disengaging the engine via pulling the clutch and block shifting more than one gear at a time seems to me to be a potentially dangerous method, your engine is disengaged from the drive as you have pulled the clutch for two gears down, rather than one, and any surprises incurred whilst executing this can overload anybodies skills . Keep the drive engaged for as long as you can is safer.

Mind you, the biggest skill for safe riding is the ability to read the road, anticipate potential hazards both on the carriageway and the traffic around you. Today I saw a moto guzzi having to ram on his brakes when a car he was about to overtake on a dual carriageway pulled out in front of him when the car suddenly notices was too close to a lorry doing 56mph to the car's 70 ish. Yes, the car was negligent by not braking, checking the road was clear to go to the outside lane and failed to anticipate the need to pull out due to the speed differential. However the Guzzi also failed to anticipate it as well, I was following the bike some yards back and already had slowed down as I could see a potential problem. Safe riding is about observation and imagination. Bilpping on down-shifting enhances your riding skills!

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SteveThackery
8 hours ago, Hickky said:

Arriving at a corner in front of you, braking, disengaging the engine via pulling the clutch and block shifting more than one gear at a time seems to me to be a potentially dangerous method, your engine is disengaged from the drive as you have pulled the clutch for two gears down, rather than one, and any surprises incurred whilst executing this can overload anybodies skills . Keep the drive engaged for as long as you can is safer.

 

Just to be clear, I was not advocating block shifting in these circumstances.  I was talking about coming to a certain stop (e.g. traffic lights that you've seen change).  What you've described is where I would just go up and down the gearbox one shift at a time to suit my speed and to allow me to accelerate away.

 

8 hours ago, Hickky said:

I guess some of this is about the amount of drag from the engine your machine will give you. However, the reliance of just the brakes to slow down must promote some instability to the machine, particularly with telescopic front forks, placing increased stress on the front tyre, where the unexpected loss of adhesion can lead to all sorts of issues.

 

You use the brakes on both wheels, obviously, so I don't see why braking must promote instability.  Basically, using the engine to brake has the same effect on the back wheel as applying the rear brake, EXCEPT it's much more difficult to modulate it smoothly and get just the right amount of retardation force.

 

The inherently clumsiness of engine braking is surely illustrated by the adoption of slipper clutches on high performance bikes, specifically to help avoid the loss of traction people were experiencing when changing down the gears.

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fred_jb
2 hours ago, SteveThackery said:

The inherently clumsiness of engine braking is surely illustrated by the adoption of slipper clutches on high performance bikes, specifically to help avoid the loss of traction people were experiencing when changing down the gears.

 

I think that may be true if you are getting your retardation through engine braking while rapidly changing down through the gears without blipping.  However, it seems to me that this isn't necessarily what many people do. I tend to just use closing the throttle to modulate my speed, through making use of engine braking, and only change down a gear, with a blip, if I slow down so much that the current gear becomes too high for my speed, so that I am always in the right gear to ensure that the motor will respond when I need to speed up again. I add braking into the mix only when I haven't anticipated a hazard early enough and so need more deceleration than engine braking alone can provide, or very occasionally when "making progress" and wanting to slow down later for a bend or other hazard.

 

With my current bike, the 1250GS, the motor provides a lot of retardation though engine braking, and is also very flexible which reduces the need to downshift at all in many situations, meaning that you can ride the bike almost entirely on the throttle with the brakes hardly needed. Shedding unwanted speed by use of the brakes involves the waste of kinetic energy gained from burning petrol, by turning it into heat in the brakes.   Anticipating the need to slow down and closing the throttle to do so slows you down by shutting off the supply of petrol to the engine during a period when the alternative of later slowing down on the brakes would mean you would still have been burning it.

 

Edited by fred_jb
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embee

We also have to take into account the different demands and circumstances on a race track and on the public roads. Racing usually involves keeping the engine more or less in the top 1/4 of its speed range pretty much at all times, so early downshifting, I don't know about anyone else but on the road I rarely adopt this approach. Slipper clutches allow a wide degree of "error" in matching engine/road speed without applying more engine braking to the rear wheel than friction will accommodate. Whether they are really necessary on a road bike is debatable, they are another "race derived" sales gimmick to some extent. I must be a riding god because my bike has a slipper clutch.

That's one of the issues I have with some of the dogma of the advanced training philosophies, 99% of us are not going to ride as though we are emergency service officers on a call so some principles of use of gears/engine speed are not really the same. Making progress versus riding to minimise fuel consumption, emissions, noise and risk don't necessarily require the same actions.

Freewheel devices were effectively banned (many years ago I think) because they remove the engine braking possibility.

On steep downhills we are advised to "use your engine braking", it's a way of applying retardation without heating and wearing brakes unnecessarily, and trucks use retarders (used to be exhaust brakes to increase engine pumping losses, but now usually electromagnetic retarders as far as I know) which will slow the vehicle without heating the brakes, there's a lot of potential energy in 44 tonnes at the top of an Alpine pass which needs to be dissipated one way or another on the way down.

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SteveThackery
1 hour ago, fred_jb said:

I tend to just use closing the throttle to modulate my speed, through making use of engine braking, and only change down a gear, with a blip, if I slow down so much that the current gear becomes too high for my speed, so that I am always in the right gear to ensure that the motor will respond when I need to speed up again.

 

Yes, that's exactly what I do.  Obviously you use the throttle to speed up and slow down, and if I'm slowing down sufficiently then I don't need to use the brakes.  In that respect I guess we all use engine braking most of the time as we accelerate and decelerate with the throttle.

 

However, I don't believe in changing down to a lower gear just to get more engine braking.  I only change down to match the engine speed to the road speed so I can accelerate away again.  If I want to slow down more quickly than closing the throttle will allow, I use the brakes.

In summary, I:

 

1/ Use the engine to accelerate and decelerate as it allows

 

2/ Use the brakes if I need to slow down quicker than 1/ allows

 

3/ Change down the gears only to match the engine to the road speed, not specifically to provide extra engine braking*

 

 

1 hour ago, fred_jb said:

I add braking into the mix only when I haven't anticipated a hazard early enough and so need more deceleration than engine braking alone can provide, or very occasionally when "making progress" and wanting to slow down later for a bend or other hazard.

 

Yes, I was going to emphasise that.  If you aim to rely only on engine braking, then you have to slow down well before each hazard, which may well annoy the people behind you and it limits your progress.  I prefer to make more progress, so I use the brakes quite a bit.  I bet most people do.

 

 

1 hour ago, fred_jb said:

 

With my current bike, the 1250GS, the motor provides a lot of retardation though engine braking, and is also very flexible which reduces the need to downshift at all in many situations, meaning that you can ride the bike almost entirely on the throttle with the brakes hardly needed. Shedding unwanted speed by use of the brakes involves the waste of kinetic energy gained from burning petrol, by turning it into heat in the brakes.   Anticipating the need to slow down and closing the throttle to do so slows you down by shutting off the supply of petrol to the engine during a period when the alternative of later slowing down on the brakes would mean you would still have been burning it.

 

I agree, if you are going for maximum fuel economy then drive as Fred suggests; brakes are wasting energy that  you've paid for.  Myself, I don't ride like that.

*PS: I think we can all agree that in extremis this policy can be temporarily suspended, such as when descending a winding 1-in-3 hill or riding on snow and ice.

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SteveThackery
22 minutes ago, embee said:

That's one of the issues I have with some of the dogma of the advanced training philosophies, 99% of us are not going to ride as though we are emergency service officers on a call so some principles of use of gears/engine speed are not really the same. Making progress versus riding to minimise fuel consumption, emissions, noise and risk don't necessarily require the same actions.

 

Actually I do agree with that.  On the other hand, I suspect that for most drivers/riders, any kind of system which makes them think much more carefully about their driving will improve their skills and safety.

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fred_jb
3 minutes ago, SteveThackery said:

 

 

Yes, I was going to emphasise that.  If you aim to rely only on engine braking, then you have to slow down well before each hazard, which may well annoy the people behind you and it limits your progress.  I prefer to make more progress, so I use the brakes quite a bit.  I bet most people do.

 

I agree, if you are going for maximum fuel economy then drive as Fred suggests; brakes are wasting energy that  you've paid for.  Myself, I don't ride like that.

 

Well, I wasn't meaning to suggest that riding on the throttle and making less use of the brakes is anything other than a personal preference, or that there is anything wrong with riding more enthusiastically. The former is my default when touring with my wife on the back, but when riding solo I tend more towards the latter.  However, when it comes to acceleration rather than deceleration, I enjoy making full use of the available performance, which is probably why my average mpg figures are so disappointingly low!  :D

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neojynx
8 minutes ago, SteveThackery said:

However, I don't believe in changing down to a lower gear just to get more engine braking.  I only change down to match the engine speed to the road speed so I can accelerate away again.  If I want to slow down more quickly than closing the throttle will allow, I use the brakes.

In summary, I:

 

1/ Use the engine to accelerate and decelerate as it allows

 

2/ Use the brakes if I need to slow down quicker than 1/ allows

 

3/ Change down the gears only to match the engine to the road speed, not specifically to provide extra engine braking*

 

:thumbsup:

 

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