CWCAM now has a Web Site: A lot of work has been done recently to provide the Group with a Web Site and now that it is in its final stages of development, it would be good to know what our Members think of it. To that end, please take time to click on this address and explore the site: WWW.IAMCUMBRIA.ORG One of the objectives of the design was to provide a vehicle for the distribution of this Newsletter. A few years ago we sent hard copies of the Newsletter through the post but we just did not have the manpower or the money to continue with that method of distribution; so we went to an electronic version of the Newsletter, sent by email: thatâ€™s where we are at present. The next logical step is to make it available on line in the near future through the Web Site. I will still send an email each Inside this Issue: month telling you the Newsletter is available, but instead of attaching the Newsletter to the email, there will be a link for you to 2. Editorial click. The link will take you straight to the Newsletter in one step. 3 Fair Fuel UK campaign: update On behalf of the Committee I would like to thank Maureen Robinson and Marc Birkett for their hard work and dedication in 3. IAM National Observer producing our Web Site. Qualification 4. Are electric cars AC or DC? 8. Brake / Gear Overlap 10. Biker Corner: 10. ABS on a bike 12. Slow; Look; Lean & Roll 14. CWCAM Committee contact details
Pirelli Visit We have organised a visit to the Pirelli factory in Carlisle on Monday 18th November, starting at 7pm. Please let us know if you would like to attend.
If interested in attending the Pirelli Factory please email Nigel MacDonald by Friday 15th November and give your details. (First come first served!!) (firstname.lastname@example.org) Highway Code question: Do you need to have side lights on, whilst parked at night? Turn to Page 13 to find out.
Fair Fuel UK update: The Fair Fuel UK campaign has done a lot to fight the relentless increase in fuel price: and the fight goes on! FairFuelUK have launched their Public and Business Polls aimed at highlighting the high prices of fuel at the pumps are affecting your cost of living or the running of your business? Fair Fuel UK will be sending the results of the Polls in a summarised analysis to every MP, every Lord, national newspapers, national and local TV and Radio outlets in the lead up to the Autumn Statement and throughout the life of the campaign. PLEASE NOTE: Your personal details will not be included in the final report sent to MPs. If you have not done so as yet, please complete the polls below: 1. The Public Poll: www.fairfueluk.com/publicpoll.html 2. The Business Poll: www.fairfueluk.com/businesspoll.html Thanks as ever for your fantastic help. Without you we can't make the Politicians listen. The more responses we collect, the more weight of influence we have.... Source: Fair Fuel UK
IAM National Observer Qualification: IAM launched their new Observer scheme earlier this year with the introduction of the National Observer qualification. They are currently working to introduce the entry level Observer qualification: the Local Observer, which is hoped will be available to Groups in the early part of 2014. IAM training is carried out the length and breadth of the country, but up until recently, there was no single standard for Observers to work to; different Groups “did their own thing” when it came to preparing Associates for Test. IAM therefore introduced a standardised set of “Competencies” that Observers are now required to work to. The aim is standardisation and quality control: an Associate training in London should now receive the same standard of training as one in Aberdeen. Within the Group we already have some Observers qualified to the new National standard (both car and bike) and the Committee decided that we should push on with this and upgrade all of our current Senior and Qualified Observers to National standard as soon as possible. To that end, the Group ran a National Observer Preparation Course on Sunday 13th October, which was well attended and received by the Group Observers. We in the Carlisle and West Cumbria Advanced Motorists Group embrace the new qualifications and have nothing to fear in complying with the new standards; we will, as always, endeavour to keep up the high standard of Observing we have shown in the past. Source: George Cairns
Are electric cars AC or DC? We are all familiar with electrical appliances, without which our way of life would be considerably more tedious! But what about electric cars; exactly how do they work? Just as we have petrol and diesel powered four stroke engines, do we have AC and DC powered electric cars? So, how does the electric car work? From the outside, you would probably have no idea that a car is electric, especially if the electric car is created by converting a normal car, it would be impossible to tell. When you drive an electric car, the giveaway is the fact that it’s nearly silent. But under the bonnet, there are a lot of differences!
The petrol or diesel engine is replaced by an electric motor;
The electric motor gets its power through a “Controller”;
The Controller gets its power from an array of rechargeable batteries;
A petrol or diesel engine, with its fuel lines, exhaust pipes, coolant hoses and intake manifold, tends to look like a plumbing nightmare; whereas an electric car is definitely a wiring nightmare! The heart of an electric car is the combination of:
The electric motor, which can be either DC (Direct Current) or AC (Alternating Current);
The motor's controller;
The motive power is provided by the batteries and all batteries have a DC output voltage. The battery comprises individual units or cells and the more cells connected together end to end (i.e. in series), the greater the output voltage. If the prime mover is a DC motor, the car will have a DC Controller; but if the prime mover is an AC motor, the Controller will produce an AC output voltage, making it an AC Controller. Whether DC or AC, electric motors comprise two parts: the inner rotating part (the Rotor) and outer stationary part (the Stator). Electric motors are also supplied with electrical power, which they convert to mechanical power in order to do useful work, such as turning the wheels of an electric car. An AC motor (a 3 phase AC motor to be precise) is mechanically more robust and efficient than a DC motor. The electrical power supplied to the stator generates a rotating magnetic field, which transfers power to the AC Motor rotor by reaching across the gap between them, without the need for mechanical contact. This makes the rotor spin on its horizontal axis, as magnetic fields generated in the rotor interact with the stator’s rotating magnetic field.
In the case of a DC motor, electrical power is supplied directly to the rotor in order to generate a magnetic field, which then interacts with a similar magnetic field created by either fixed magnets or current running through coils of wire wrapped around the stator. The interaction of the two fields causes the rotor to spin and -as in the case of the AC motor- the spinning rotor provides the motive power that ultimately drives the car wheels. In the case of the DC motor, a commutator and carbon “brushes” are required in order to transmit electricity directly to the spinning rotor. (Ed’s note: The name “brushes” comes from when they were originally made from a stiff bundle of copper wire, shaped just like a tiny “witches broom.” A solid carbon brush not only conducts well, it also lubricates the spinning commutator with which it is in contact. However, the fine carbon film deposited on the commutator needs to be cleaned off, from time to time, to prevent current seeping out and arcing across the surface of the commutator, leading to sparking and inefficiency!)
One of two “Brushes”
The mechanical contact between the commutator and the brushes leads to frictional loss and power loss due to sparking; neither of which you get with an AC motor. The AC motor is therefore far more robust and with less mechanical wear and tear, it’s more efficient than the DC motor. Whether the motor is AC or DC, the Controller takes power from the batteries and delivers it to the motor. In the case of a DC Controller and motor, the accelerator pedal is linked to a pair of potentiometers (variable resistors); the potentiometers provide a signal that tells the Controller how much power to deliver. i.e. The Controller delivers zero power when the car is stopped; full power, when the driver puts the accelerator pedal to the floor; or anything in between, depending on how much the accelerator is depressed.
A pulsating DC voltage
The Controller reads the signal from both potentiometers and they must be equal: if not, the Controller does not operate: this guards against a situation where one of the potentiometers fails in the full-on position. (Ed’s note: the possibility of both Controllers failing in the full-on position must be assumed to be negligible!) The Controller “reads” the setting of the accelerator pedal from the potentiometers and regulates the power accordingly by pulsing it on and off. For example, if the accelerator is pushed halfway down, the Controller reads that setting from the potentiometer and rapidly switches the power to the motor on and off so that it is on half the time and off half the time. But if the accelerator pedal is 25 percent of the way down, the Controller pulses the power so it is on 25 percent of the time and off 75 percent of the time. Most Controllers pulse the power more than 15,000 times per second, in order to keep the pulsation outside the range of human hearing. The pulsed current causes the motor housing to vibrate at that frequency, so by pulsing at more than 15,000 cycles per second, the Controller and motor are silent to human ears.
(Ed’s note: that’s all very well, but what about the poor old dog in the back?)
In the case of an AC Controller, the job is a little more complicated, but the principle is the same!
The Controller creates three pseudo-sine waves, to simulate the three phase output voltage of an alternator (i.e. an AC generator). It does this by taking the DC voltage from the batteries and pulsing it on and off; it also reverses the polarity of the voltage 50 times a second, to simulate the 50 Hertz output frequency of a traditional AC generator. The Red curve is a simulated Sine wave (single phase) produced from a DC source. The Green waveform is a true Sine wave for comparison. The AC Controller produces 3 such simulated Sine waves, displaced in time so that they are 1200 out of phase, to simulate a 3 phase AC voltage; traditionally referred to as the Red, Yellow and Blue phases The “AC voltage” is applied to the AC motor to produce the torque that drives the car. If the motor is a DC motor, then it may run on anything from 96 to 192 volts. If it is an AC motor, then it probably is a three-phase AC motor running at 240 volts AC with a 300 volt battery pack. DC installations tend to be simpler and less expensive. A typical motor will be in the 20 to 30 kilo Watt range. A typical controller will be in the 40 to 60 kilo Watt range. For example, a 96 volt controller will deliver a maximum of 400 to 600 amps. DC motors can be over driven for short periods of time. That is, a 20 kilo Watt motor can deliver 100 kilo Watts for a short period of time; effectively delivering 5 times its rated horsepower, which is great for short bursts of acceleration: the only limitation is heat build-up in the motor. Too much over driving and the motor heats up to the point where it self-destructs. AC installations allow the use of almost any industrial three-phase AC motor, so if it is a “DIY” project, this makes finding a motor with a specific size, shape or power rating that much easier. AC motors and controllers often have a regeneration feature; that is, during braking, the motor turns into a generator and delivers power back to the batteries. (Ed’s note: you have to hand it to electric motors, they are really cool. Drive the motor with electrical power and obtain mechanical power in return; but if you reverse the process and supply mechanical power to turn the rotor, the “motor” becomes a “generator” and produces electricity that can then be used to recharge the battery. Now just stop and think how great that would be if a car engine could do the same! You would be able to shove exhaust gases and pollutants up the exhaust pipe and watch petrol or diesel flooding out of your engine, back into the tank!! That would be really, really cool…unfortunately it contravenes the 2nd Law of Thermodynamics, which basically states that Entropy (i.e. the state of disorder of things) never decreases. i.e. A broken cup can’t jump back onto the table and fix itself, decreasing its state of disorder in the process.) Right now, the weak link in any electric car is the battery; or battery array to be more precise. There are at least six significant problems with current lead-acid battery technology: 1. They are heavy (a typical lead-acid battery pack weighs 500 kilos or more; 2. They are bulky and therefore take up a lot of the available space;
3. They have a limited capacity (a typical lead-acid battery pack might hold 12 to 15 kilowatthours of electricity, giving a car a range of only 50 miles or so; 4. They are slow to charge (typical recharge times for a lead-acid pack range between four to 10 hours for full charge, depending on the battery technology and the charger); 5. They have a short life (three to four years, perhaps 200 full charge/discharge cycles); 6. They are expensive! Who knows what developments there will be in the electric car market; for now, they remain very expensive and have limited range. Source: How things Work (edited and manipulated by George Cairns)
Brake Gear Overlap: Hopefully this term means something to all of our car drivers; if not, read on! The SYSTEM of car control provides us with a systematic approach when dealing with hazards, so that nothing is left to chance. The SYSTEM comprises 5 phases (or 4 phases if you like, superimposed on continual INFORMATION taking / using / giving). But being old fashioned, I prefer referring to the 5 phases of the SYSTEM.
Consider approaching a multi-lane roundabout with the intention of going right. Information is continually gathered about the roundabout itself; the traffic ahead; the traffic behind; traffic approaching the roundabout from your right –which may then become priority traffic if they finish up vying for the same road space when you are about to join the roundabout; traffic approach the roundabout from the left, that you will have priority over if they reach the roundabout at the same time as you do; the road condition; the weather; and so on! Position on approach is dictated by your intended exit, in this case your intention is to turn right, you would therefore take the right lane on approach if there were two lanes, or the indicated lane for right turns if there were more than two. (More information as you signal right from the Route Board; if there is someone to benefit from the signal.) Speed: Now is the time to adjust your speed to a suitable speed that will allow you to reach and then –hopefully- splice onto the roundabout smoothly and effectively. This is where most drivers overlap braking and gear changing: remember that…… Brakes are for slow, gears are for go! Braking starts off gently and progressively builds up until the speed of approach to the roundabout is well under control (i.e. you should not approach too fast and there should be no need for late, harsh braking!) 8|Page
On approach to the roundabout, don’t change down even if you are in 4th, 5th or 6th gear. Speed drops off under smooth progressive braking and we know from experience there comes a point at which the road speed is too low for the gear, causing the engine to struggle and vibrate, which is very bad for the crankshaft! To avoid this happening, as you brake, slowly push the clutch pedal in just before the engine starts to struggle; initially push it in just a little but progressively more as your speed drops off; in this way you keep both hands on the wheel as there is no need for a gear change. Further Information gathering, with particular attention being paid to the vehicles ahead, which may stop unexpectedly and to vehicles approaching from the right. Look, assess and decide if it’s safe to join the roundabout. Plan to stop but be prepared to go! GEAR: Once you have decided on your course of action, come off the brake and select the relevant gear; your selection will be dictated by the road speed at that point; which in turn is dictated by your assessment of the situation. With the correct gear selected, execute your driving plan and hopefully join the roundabout traffic smoothly and effectively. Throughout the SPEED – GEAR phases of the SYSTEM there was no overlap between braking and changing gear, as you reduced the speed BEFORE selecting the relevant gear. Don’t confuse brake gear overlap with brake clutch overlap! Whilst braking you gradually ease the clutch pedal in to take the stress off the engine. Note that if the clutch was pushed in fully when braking, it also avoids undue stress on the engine but by doing so, you would be coasting, which is definitely not acceptable as there is no engine braking and tyre grip is greatly reduced, hampering effective braking and steering! Acceleration: Once off the roundabout the correct amount of acceleration would be required to maintain progress. Why do Observers go on about brake gear overlap and is it that important? Lots of people drive and have no knowledge of brake gear overlap and the need to avoid it and yet they may be considered to be effective drivers. But “Advanced Drivers” are “advanced” because of our application of the SYSTEM allowing us to deal pro-actively and systematically with all driving hazards; part of that discipline is applying the SYSTEM, which calls for ....SPEED; GEAR.... in that order. If you sit next to a driver who is not advanced trained and you watch the way they approach hazards requiring them to slow down and change down, you are likely to observe late braking and hurried gear changes during the turn into a side road or on approach to a roundabout or T Junction. Application of the SYSTEM and avoidance of brake gear overlap means that everything is carried out in plenty of time; there is no rush; it is calm, effective and efficient: that’s why we do it! (Ed’s note: in some circumstances it may be helpful to overlap braking with gear change, by braking normally but changing the gear towards the end of the braking period. Can you think when this would be appropriate? Turn to P13 to find out!) George Cairns
Biker Corner: ABS on a bike: ABS was invented by Gabriel Voisin in the late 1920’s when working on aircraft braking systems. The technology has been around in the car industry for about 50 years; although early designs were very primitive compared to the sophisticated electronic ABS systems found on modern cars. ABS first appeared on bikes in the mid 1980’s and the first ABS bike was probably a BMW 1988 K100 model. Modern bikes equipped with ABS are substantially safer than non-ABS bikes: of that, there’s little doubt! What does ABS do? If you have to brake hard, especially on a slippery surface, there is a good chance that the front, back or both wheels will lock up, which causes them to lose grip on the road surface and as most of us know from bitter experience, the end result can be a skid and a crash! ABS detects when a wheel (front or back) is about to lock, fractions of a second before it does! The ABS then regulates the braking force to the relevant wheel allowing the wheel to keep turning and Even on the Continent, cars pull out in therefore to keep gripping the road surface. With front of bikes!! impending wheel lock over, the ABS once more applies maximum braking effort to the relevant wheel or wheels until they are about to lock, whereon it repeats the cycle of regulating the braking force to prevent wheel lock. How does it know a wheel is about to lock? The first ABS incarnations were purely mechanical and often imprecise and ineffective, with relatively big lag times between the need to apply the brakes and the application of braking force. Modern electronic based ABS is much more effective and mechanically simpler. There are 4 major components of an ABS system, they are the:
Sensor array; Control unit; Pump; Valves to regulate brake pressure;
Sensors: The main sensor is normally the “speed sensor”. Take a look at the front or back wheel of an ABS bike and you will see a slotted disc close to the centre of the brake disc, or rotor. This is the “pulsar ring”, which allows the sensor to measure the wheel’s speed. Each time a slot passes a detector it is recorded; the more slots passing the detector per second, the faster the wheel will be spinning. Conversely, the fewer slots passing per second the closer the wheel is to stopping under normal brakin;g or locking under extreme braking! This real time “wheel speed” (not the bike’s road speed!) is constantly fed to the ABS ECU (Electronic Control Unit). Modern ABS systems also have Gyros and Handlebar Sensors for detecting the camber (or lean angle) of the bike; which helps the ABS ECU function correctly. (i.e. As the rider, you wouldn’t brake 10 | P a g e
as hard as you could when the bike is leaned over or when the bars are turned; likewise the ABS will modify the braking pressure when it “knows” through its sensors that either or both of these conditions exist.)
ECU: The Electronic Control Unit receives multiple readouts from the bike sensors connected to it: the higher the frequency of these readouts and the comparison computations, the higher the efficiency of the ABS. Sensor information is analysed by the ECU and the results are compared with preset parameters. It then uses pre-programmed algorithms to regulate the braking force applied to either or both wheels. The higher-spec ECUs can be constantly updated and can “learn” a lot of scenarios or maps to be used in certain situations. Furthermore, different styles of bikes come with different ABS mappings, maximising the riding performance and providing safe braking in various scenarios. Thanks to digital technology, these ABS mappings can be recalled and cycled through with just a press of a button and they become operational in milliseconds.
Pump and the valves: These are the physical components used by the ABS to control the braking force. Since the ABS is regulating the pressure in the brake lines, it needs a pump that works both ways: i.e. it must be able to increase and decrease the brake pressure, depending on the requirement at any instant in time. The pump acts like any conventional electric pump with a master cylinder and piston; the operation of the valves is equally simple. The ABS kicks in when the braking pressure applied the rider is too big; the ECU then calculates how much it should lower the braking pressure to prevent the wheels from locking up and losing grip. The amount of “release” is sent as electronic data to the solenoid valves which are moved in the right direction to decrease the pressure pushing the calliper pistons, thereby easing the braking force. As the wheel slip potential is eliminated, the ECU sends another command to the pump and moves the valves to another position, allowing the pressure of the initial braking manoeuvre to be restored, basically re-applying the hard braking pressure. This process only takes fractions of a second and is repeated until the bike stops. When the ABS works, riders will feel slight vibrations in the lever or pedal, as the pressure in the line is constantly modulated: this is quite normal and satisfyingly reassures that the ABS is operating!
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While some say that the same braking can be obtained by a professional trained rider, this is only partially true, as the human brain cannot have the processing and precision of the digital system in assessing the various riding environments. Click on the following link to see a U-Tube video comparing an ABS bike and a non-ABS bike. http://www.youtube.com/watch?feature=player_embedded&v=5U7dzYSE24Y Source: Auto Evolution
Slow; Look; Lean & Roll: What is this; it’s a formula for safe cornering! Slow: The old adage: “In slow, out quick” applies to every corner in the world, whether you are driving or riding through it! Use the SYSTEM of motorcycle control on approach to a bend to determine if it is a right bend or a left bend, as this will determine your Position on approach. At the same time, analyse the Limit Point to see if it is moving away; standing still or coming towards you: remember that the faster the Limit Point moves away, the gentler the bend. Ask yourself the question: “Can I stop in the distance I can see to be clear, whilst staying on my side of the road?” (This is the Safe Stopping Rule). Coming off gas will slow the bike but consider that engine braking only applies to the back wheel. Effective braking (if required) is achieved with the bike in the upright position, by coming off gas and applying the brakes: front first and then back a fraction of a second later. (Note that if the bend is tighter than you anticipated and you have to scrub off a lot of speed, use the front brake only! If you brake really hard with the back brake, under these circumstances, there is a strong possibility that the back wheel will stop or slow significantly whilst it is rising up from the road surface, owing to the forward weight shift produced by front wheel braking. When the back wheel falls back to the road surface under gravity, it may well bounce out to the left or right, initiating a pendulum effect that will fill your trousers quicker than you can say: “What’s that smell?”
Now that you have the initial Information; Speed and Position set up for the bend it’s time to….. Look: To be more precise, look through the bend in the direction you want the bike to go! Yes you can swivel your eyes in their sockets, but turning your head in the direction in which you want to go will help with directional control and stability in the turn. Another old adage: “Look where you want to go and go where you look”
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You will also be looking to see what the traffic is like ahead and astern; what the condition of the road surface is; are there any hazards such as loose gravel or potholes?; what is the Limit Point doing now?; is the next bend a left or a right? You are now at the point where you need to tip the bike into the bend; it’s therefore time to…. Lean & Roll: Using Positive Steering (i.e. the new term for Counter Steering) and leaning the bike in the direction of the bend, will initiate the Rolling Cone effect and tip the bike into the turn. At the same time GENTLY Roll on the throttle, as every bend in the world should be taken under light acceleration! (Car or bike: the same advice applies!) In a bend, the Corner Force (Centripetal Force (F) to be precise: F = (mv2)/r where ‘m’ is the mass of the bike and rider; ‘v’ is the velocity of the bike and ‘r’ is the radius of the turn) acts on the bike and points inwards, towards the centre of the turn. (Oh yes it does…!) This Force demand has to be met and the bike does this by giving up some of its energy: with less energy to thrust it forward, the bike slows down in the bend, even if the throttle remains constant! On slowing down, weight shifts to the front wheel (any form of slowing will do this, heavy front wheel braking giving the most extreme example of forward weight shift!) So just at the point when you require maximum stability, weight is moving forward onto the front wheel. To counteract this, roll on the gas and weight will move to the back wheel of the bike; just as it does under normal acceleration. With just the right amount of throttle you will redress the effect of the forward weight shift, without making the bike sit back under excessive acceleration. In other words, you are using the throttle to maintain speed in the bend and not to increase it (not at this point anyway!) On nearing the exit of the bend, the Limit Point will move rapidly away and as you bring the bike upright, progressively put on more gas –if it’s safe to do so- and chase that Limit Point: this would be the Acceleration phase of the SYSTEM. Slow, Look, Lean and Roll does not contradict the SYSTEM; it actually enhances it. So, next time you ride towards a bend, as well as thinking SYSTEM, think to yourself: Slow; Look; Lean & Roll. Have fun!! Source: George Cairns
Brake / Gear overlap: It may be helpful to overlap braking with gear change by braking normally but changing the gear towards the end of the braking period slowing before turning into a side road when there is a vehicle close behind or approaching; or when making a sharp turn to the right or left when there is a vehicle close behind or approaching; or when going downhill and there is a need to reduce speed, for example before entering a bend. Reference: Roadcraft (New edition) Page 37.
Answer to Highway Code question on p2: HC Rule 250 states Cars, goods vehicles not exceeding 1525kg unladen weight, invalid carriages, motorcycles and pedal cycles may be parked without lights on a road (or lay-by) with a speed limit of 30mph or less, if they are at least 10 metres from any junction, close to the kerb and facing in the direction of traffic flow; or if in a recognised parking place or lay-by. Other vehicles and trailers, and all vehicles with projecting loads MUST NOT be left on the road at night without lights. 13 | P a g e
CWCAM Committee: Group Officers
Members of Committee and Technical Advisor
Neil Stanton National Bike Observer 07919 676739 email@example.com
Reverend Ken Wright 01946 833536 firstname.lastname@example.org
Glynis Peacock Senior Car Observer 01900 826005 email@example.com
Nigel MacDonald Senior Bike Observer 07595 122765 firstname.lastname@example.org
Maureen Robinson National Car Observer 07740 809628 email@example.com
Chris Hardy Qualified Bike Observer Qualified Car Observer 07876 254080 firstname.lastname@example.org
Treasurer & Newsletter Editor
George Cairns National Car Observer National Bike Observer 07974 826 970 email@example.com
Steve Topping Qualified Bike Observer 07802 870 282 firstname.lastname@example.org
Technical Advisor to the Committee: Alan Bragg IAM Examiner 07724 165092 email@example.com
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