NGK Spark Plug DCPR8E [4339] Plugs [Box 10]

NGK Spark Plugs

Brand: NGK

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MOTORCYCLE HELMET GUIDE

HOW TO CHOOSE THE PERFECT MOTORCYCLE HELMET: YOUR GUIDE TO SIZES, TYPES AND WHAT TO LOOK OUT FOR.

*Complete size guide at the end of this article

Essential tips to finding your perfect fit:

Be aware of the unique features and strengths of the helmets you may be looking at
Take time to familiarise yourself with the construction, size and homologations before choosing your helmet
Features key for any type of helmet include its maximum safety, the field of vision and your comfort

Some features of different helmets:

Full-face: closest to what professional riders wear, particularly light, with advance sport aerodynamics
Modular: great comfort and practicality, can be opened when stationary
Adventure: inspired by the off-road style of riding, their peak protecting against the sun and any debris, can be used in different configurations

IMPORTANT! The innermost layer with respect to the shell of the helmet is EPS, expanded polystyrene, which is there to absorb the force of impact. EPS is not an elastic material, so it doesn't return to its original shape after compression following an impact. THAT MEANS IT CAN NO LONGER ABSORB IMPACTS IN THE COMPRESSED AREA. WHICH IS WHY A HELMET THAT HAS CUSHIONED AN IMPACT MUST BE REPLACED.

MEASURING YOUR HEAD:

Using a tape, measure around your head about an inch above the ears, across the forehead (about an inch above the eyebrows), and over the natural bump at the back of your head. The measurement should lie somewhere within 50-64cm (on average).

CHOOSING THE CORRECT HELMET SIZE:

*Complete size guide at the end of this article

Once you chose your preferred helmet, use your measurements as a guide to the size you choose. When your measurements lie between sizes, lean towards the smaller size as the lining of the helmet will give slightly over time, so you need it to be snug without being uncomfortable at time of choosing.

Using the table provided by the manufacturer to find the corresponding size will give the correct measurement or size you should try on. Heads with the same measurements can have different shapes, it is always a good idea to try a helmet before committing to it.

TRYING IT OUT:

When you put your new helmet on for the first time move it around to make sure the crown feels like the correct size. Keep it on for some time and make sure you are comfortable, push against the forehead are as that is most likely to feel uncomfortable.

When fastening the retention strap do not make it too tight against the throat, on the other hand, do not let it be loose so that the helmet could come off easily.

Check if you can get a couple of fingers between the top of the cheek pads and your cheeks. If you can then you might need a size smaller, though, you could buy larger cheek pads to fill in the gap. Make sure this is not too loose as it will limit the safety of the helmet.

The visor protects you against more than air and insects, it acts as a shield protecting your face against impact. When trying on your helmet, make sure the width of the visor, both horizontally and vertically, gives you a wide enough field of vision. It is important you do not have obstructed vision when riding with your helmet on, if you feel it is not the correct width do check for other helmets with a bigger visor.

WHAT TO LOOK OUT FOR

You need to pay attention to the safety of the helmet you ultimately choose.

For those who use their bikes a lot, it is best to opt for a helmet with an outer shell in composite fiber or carbon fiber.

For short or medium urban and touring use, thermoplastic resin helmets are a good choice, especially for those new to riding, or those not looking for a featherweight or race performance.

Consider the composition of the absorbent layer, which is safer if it is in EPS that varies in density depending on the points of the head it must protect.

Ventilation: increased heat slows down reflexes and affects rider perception. It is important that you look out for the helmet that does not give you the air flow and ventilation system you need to ride comfortably. Helmet shapes with more aerodynamics and fluid heighten rider comfort and reduce air resistance.

WHEN TO CHANGE YOUR HELMET

A helmet’s life cycle depends on many things: where, how, how often it is used, and the care taken with it. Some components of the helmet, like the EPS, tend to deteriorate over time.

The general suggestion is to change your helmet at least every 5 years.

Before the 5 years, you should replace your helmet if there are clear visible signs of wear on the shell, the straps, EPS, or the mechanisms, or when the helmet absorbs an impact.

SIZE GUIDE

(Use as a generic guide only, may not apply to some brands)

SIZE	CENTIMETERS	INCHES	HAT SIZE
X SMALL	53-54	20 7/8 - 21 1/4	6 5/8 - 6 3/4
SMALL	55-56	21 5/8 - 22	6 7/8 – 7
MEDIUM	57-58	22 1/2 - 22 7/8	7 1/8 – 7 ¼
LARGE	59-60	23 1/4 - 23 5/8	7 3/8 – 7 ½
X LARGE	61-62	24 - 24 3/8	7 5/8 – 7 3/4
2X LARGE	63-64	24 3/4 - 25 1/8	7 7/8 - 8
X LARGE	65-66	25 5/8 - 26	8 1/8 – 8 1/4

QUICK GUIDE ON HOW TO MAKE SURE THE SIZE YOU CHOSE IS CORRECT

A helmet too tight will be uncomfortable, whilst one too loose will not fulfil its protective functions.

Helmets provide maximum protection only when the size is correct.

FIVE STEPS TO MAKING SURE THE SIZE YOU CHOSE IS CORRECT:

Put the helmet on and fasten it, make sure the strap is neither too loose nor too tight; it must be close-fitting, but nor uncomfortable.
Once on, there should not be a gap between the head and padding. The helmet should fit snuggly around the whole face.
You should not feel any pressure points, especially in the front area and on the nape of the neck. It is best to keep the helmet on for some time to make sure there are no uncomfortable contact points.
Tilt the helmet sideways and up and down. A full-face helmet of the right size should not move around, the cheeks should remain in contact with the cheek pads following their movement. If the helmet moves around, the size is wrong.
To test the retention, with the helmet fastened on, tilt your head slightly forward and apply light pressure at its rear bottom edge. The helmet must not slide forward.

MOTORCYCLE CLOTHING GUIDE: GLOVES

How to find the best fit for your motorcycling gloves:

Remember that sizes vary between manufacturers, some gloves may fit slightly different to what you expect based on your measurements.

Choose the right motorcycle gloves style:

What will you use them for?

Shop MotoGB gloves offer a maximum level of protection for track and fast riding, but they can be uncomfortable and restrictive for long touring rides. Similarly, touring gloves probably won’t be the best fit for short trips on your motorbike, you will definitely need them if you will be spending lots of riding time on your bike.

What kind of weather do you usually ride in?

Certain gloves offer better protection from the weather conditions you ride in. The correct pair of gloves should not only fit comfortably on your fingers, it should protect your hands from the temperature, wind, rain, sun, etc. You might want to look for all-weather gloves made of textile if you are looking for one reliable pair for all year around. If you want to ride in warmer temperatures, you should consider a pair of lightweight leather riding gloves to keep the heat off.
Depending on the nature of your riding you will require different levels of abrasion protection, you should keep this in mind when choosing your motorcycle gloves.

What to look out for when choosing your motorcycle gloves:

Finger Feel: make sure the gloves are not too tight, but not too loose so that they could slip off. Feeling comfortable in your motorcycle gloves will allow you to have better control of your vehicle and in turn will make your ride safer.
Size & Fit: do the gloves have adjustable straps, will they fit under or over your motorcycle jacket, do they fit well and comfortably?
Features & Protection: look at what level of protection the gloves offer; will it be compatible with your motorcycling tendencies? Look at the length of the gloves and whether they are comfortable for you.
Construction: figure out what material suits your needs best and look for gloves made in such material, will it be leather or textile? The material of your motorcycle gloves will affect their feel, quality, and lifespan.

How to measure your hand size:

Using a flexible tape measure around the palm of your hand below the knuckles excluding the thumb
Measure your hand in a fist for a more accurate measurement
Holding you hand out flat measure the length from the tip of your fingers (longest) to the base of your hand

MOTORCYCLE GLOVE SIZE GUIDE *(1 INCH= 2.54 CM)

GLOVE SIZE		XS	S	M	L	XL	2XL	3XL
SIZE NUMERIC	INCHES	6	7	8	9	10	11	12
HAND CIRCUMFERENCE	CM	15	18	20	23	25	28	30
HAND LENGTH	CM	16	17	18	19	20	22	23

*Women’s glove sizes will vary to this size guide slightly.

If you plan on wearing under gloves, remember it might be useful to size up to allow a comfortable fit.

MOTORCYCLE CLOTHING GUIDE: JACKETS

How to find the perfect motorcycling jacket:

Always consider the origin of the jacket you are looking at, as UK sizes are different to European sizes.
If you have a wider neck, look for a jacket with an adjustable collar.
If you like to tuck your gloves in to your jacket, look for a jacket with adjustable cuffs.

CHEST/BUST: using tape measure the fullest part of your chest/bust
WAIST: measure around the narrowest part, your waist
HIPS: measure around the fullest part of your hips

Choose the right style of motorcycle jacket:

Think about the style of the jacket you want and whether it is compatible with your style of riding.

Leather jackets offer more abrasion protection; however, these are not waterproof motorcycle jackets and can be quite heavy.
Textile jackets are often waterproof, but might not be the right fit for a sports motorcycle bike.
Short jackets are good for sports bikes, they will not be too baggy and ruck up at the front.
Longer jackets suit touring and upright bikes, keeping your waist warmer.

If you are looking for the perfect motorcycling jacket all year round, look out for ones with a removable thermal lining.

How to choose the safest motorcycling jacket:

It is good to have CE approved armour in the elbows and shoulders, but look further for CE back protection. Many jackets will have a pocket where you can add protective gear to make your jacket safest for the road. Look for abrasion resistant materials such as polyester, or cordura fabric.

For your comfort and safety, look for a jacket which has adjustability in as many parts of its construction as possible; ribbed stretch panels at elbows allow easy flexing with the body, adjustment tabs at cuffs, neck collar, waist, arms, etc. allows for a snug yet comfortable fit. Feeling comfortable in the motorcycling jacket you choose is essential for a stress-free ride with high mobility for your safety.

MEN’S MEASUREMENTS GUIDE *(INCHES/ 1 INCH= 2.54 CM)

SIZE (INCHES)	XS	S	M	L	XL	2XL	3XL
CHEST	34-36	36-38	38-40	40-42	42-45	45-48	48-51
WAIST	28-30	30-32	32-34	34-36	36-39	39-42	42-45
COLLAR	14	14.5-15	15.5-16	16.5-17	17.5-18	18.5-19	19.5-20
TROUSERS SHORT	30	30	30	30	30	30	30
TROUSERS REGULAR	32	32	32	32	32	32	32
TROUSERS LONG	34	34	34	34	34	34	34

WOMEN’S MEASUREMENT GUIDE *(INCHES/ 1 INCH= 2.54 CM)

SIZE (INCHES)	XS	S	M	L	XL	2XL
NUMERIC SIZE	6	8-10	12-14	16-18	20-22	24
BUST	30 ¾	32 ¼- 34 ¼	36 ¼- 38	40 ¼- 42 ½	45- 47 ¼	49 ½
WAIST	24	25 ½- 27 ½	29 ½- 31 ¾	34- 36 ¼	38 ½- 41	43 ¼
HIPS	33 ¾	35 ½- 37 ½	39 ½- 41 ½	43 ¼- 45 ¼	47 ½- 50	52 ½
TROUSERS SHORT	30	30	30	30	30	30
TROUSERS REGULAR	32	32	32	32	32	32
TROUSERS LONG	34	34	34	34	34	34

MOTORCYCLE CLOTHING GUIDE: TROUSERS & JEANS

How to find the perfect fit for your motorcycling jeans and trousers:

Note that ladies’ clothing is cut differently to men’s clothing, and they do vary depending on manufacturer.

Think about how you like to wear your jeans/trousers, fit your preferences to the style and size to find the perfect match.

How to measure yourself

WAIST: measure the narrowest part of your torso, as you would with a normal pair of jeans or trousers
INSEAM: measure from the top of your inner leg along the inside seam to the bottom of your leg
Many trousers will have length options from regular-short-long, depending on your height and the length of your legs you want to consider which is the best option for you.

Choose the right style of motorcycle trousers:

Leather will give you really good protection, especially when fitted with additional CE approved armour in the knees and hips. They can be worn on their own and will provide a snug fit. However, leather trousers may not be the best option for colder days, and they are not waterproof. Textile trousers tend to be a bit baggier as the material doesn’t stretch. The closer fitting, the more protection they offer. Some denim jeans are also fitted with CE certified protective gear which allows you to stay comfortable and safe.

Look out at how the trousers you choose fit around your waist, whether they have Velcro, if you will need a belt, or if they zip up to the jacket. Also, make sure they are the right fit for the boots you will be wearing. Leather trousers are usually worn inside the boots, whilst textile trousers are worn outside to keep the rain out of your footwear.

MEN’S MEASUREMENTS GUIDE *(INCHES/ 1 INCH= 2.54 CM)

SIZE (INCHES)	XS	S	M	L	XL	2XL	3XL
CHEST	34-36	36-38	38-40	40-42	42-45	45-48	48-51
WAIST	28-30	30-32	32-34	34-36	36-39	39-42	42-45
COLLAR	14	14.5-15	15.5-16	16.5-17	17.5-18	18.5-19	19.5-20
TROUSERS SHORT	30	30	30	30	30	30	30
TROUSERS REGULAR	32	32	32	32	32	32	32
TROUSERS LONG	34	34	34	34	34	34	34

WOMEN’S MEASUREMENT GUIDE *(INCHES/ 1 INCH= 2.54 CM)

SIZE (INCHES)	XS	S	M	L	XL	2XL
NUMERIC SIZE	6	8-10	12-14	16-18	20-22	24
BUST	30 ¾	32 ¼- 34 ¼	36 ¼- 38	40 ¼- 42 ½	45- 47 ¼	49 ½
WAIST	24	25 ½- 27 ½	29 ½- 31 ¾	34- 36 ¼	38 ½- 41	43 ¼
HIPS	33 ¾	35 ½- 37 ½	39 ½- 41 ½	43 ¼- 45 ¼	47 ½- 50	52 ½
TROUSERS SHORT	30	30	30	30	30	30
TROUSERS REGULAR	32	32	32	32	32	32
TROUSERS LONG	34	34	34	34	34	34

MOTORCYCLE CLOTHING GUIDE: BOOTS

Motorcycle boots are an essential part of each rider’s motorcycle attire. The protection and comfort they provide is vital in ensuring you are safe and comfortable. This is why choosing the correct pair of riding boots is key.

Ladies’ footwear will run smaller than men’s; you can use your shoe size as a guide for the best fit for your motorcycling boots, though depending on the material and manufacturer the sizes may vary.

Choosing the perfect style of boots:

Depending on how you like to wear your boots, inside or outside your trousers, have a look at the shin protection to make sure you will have a comfortable fit.
Decide the level of protection you will require for the style of riding you engage in as some boots have more protective features which might not be needed or comfortable for your style of riding.
Be weary of certain protective features such as metal toe guards, as they might scratch your bike as you mount it.
Adventure off-road boots offer lots of protection, but you might struggle with the changing of gears if it is a sports bike you ride. Touring boots will be great for long journeys, and harsher weather conditions as they are waterproof and warm, but it could get too warm if you are riding on track in the summer
You might have to consider owning multiple pairs for the different conditions you ride in, to ensure the perfect fit and suitable protection.

Finding the perfect fit:

Leather boots will likely feel stiff at the start, they usually give in after some wear, if after trying them on they do not feel comfortable it may be the size which is the issue. Your motorcycling boots should never be too stiff or too tight with no room to move, they should not feel uncomfortable. You should have mobility in your motorcycle boots so that you can ride safely and comfortably, but not so much that your foot could twist in case of accident.

How to measure your feet:

Rest your bare foot at a right angle to a wall, keeping the heel right up against the wall.
Using a tape measure the distance between the wall and the tip of your foot.
Repeat for your other foot, use the bigger measurement as a guide for your size.

SHOE SIZE CONVERSION GUIDE

MEN'S

EU	UK	US	Foot length (cm)
39	5.5	6	24.6
40	6.5	7	25
41	7	7.5	25.4
42	8	8.5	26.3
43	9	9.5	27.2
44	9.5	10	27.6
45	10	11	28
46	11	11.5	28.9
47	12	12.5	29.8

WOMEN’S

EU	UK	US	Foot length (cm)
35	2	4	21.2
36	3	5	22.1
37	4	5.5	22.9
38	5	6.5	23.7
39	5.5	7	24.6
40	6.5	8	25
41	7	8.5	25.4
42	8	9.5	26.3
43	9	10	27.2

SPARK PLUG DESIGN
Every year the range of NGK spark plugs grows to accommodate the ever increasing demands of modern engines. Spark plug design must take into consideration many features
of an engine including physical dimensions; combustion chamber shape; cooling abilities; fuel and ignition systems. Spark plugs play a vital role in producing the maximum power
from an engine whilst keeping fuel consumption and emissions to a minimum. Choosing the correct spark plug type will help a vehicle manufacturer meet legislated emission targets and
assists the motorist in getting the best from their engine.

Increases in the size and the requirement to improve the cooling of the inlet and exhaust valves have meant that the space available for the spark plug is severely restricted on some
cylinder heads. A change in spark plug design; possibly the adoption of a taper seat and extended reach (threaded portion) or even the use of a smaller diameter is often the answer. Some engines require the use of two spark plugs per cylinder and again due to space restrictions these might be of different sizes.

Changes in fuelling systems and the fuel itself have meant some special features being adopted at the ‘firing end’ of the spark plug. Extra projected types push the spark position into the heart of the combustion chamber to promote better combustion of the fuel/air mixture; which is weaker than ever in an effort to improve economy. Modern engines manufacturers often require increased spark gaps to allow a longer spark duration; which again aids more efficient combustion.

To combat the ‘cold fouling’ effect that can occur in some engines using unleaded fuels specially arranged ground electrodes are sometimes used. These can force the spark to discharge across the insulator and thus burn away any built up carbon that could cause poor starting or misfires. It is not uncommon to find two; three or four ground electrode arrangements in new vehicles. The use of precious metals on the tips of the spark
plug electrodes is not uncommon especially on higher performance engines. Whilst these spark plugs do have increased service life they are often specified because of their superior ignition qualities.

Our engineering departments work very closely with the engine and vehicle manufacturers to produce the ideal spark plug type for each application. Any change in production is expensive for a manufacturer and therefore new spark plug types are only produced where necessary. NGK employ the very latest production technology to ensure that every aspect is catered for – performance; economy and value.

HEAT RANGE AND HEAT DISSIPATION
Spark plugs do not produce heat in the combustion chamber. One of the functions of the spark plug is to dissipate some of the heat produced during combustion. This is mostly transferred into the cylinder head. The 'Heat Range' indicates the measure of the spark plug's ability to do this. A 'hot' spark plug is designed to maintain a sufficiently high temperature at the insulator nose to burn off carbon and oil deposits. A 'cold' spark plug is designed to allow a faster transfer of heat to the cylinder head thus preventing overheating and premature failure.

The heat range selection is obviously a complex task with many factors to take into account. NGK engineers therefore make specific recommendations for each engine and the use to which it is put.

WIDE HEAT RANGE
A wide range spark plug is more flexible and performs equally well in a hot or cold engine under stop and go city driving or fast motorway cruising. Engines that tend to run hot need cold type plugs. Those that run cold demand a hotter type. The specific plug for any engine is determined by the plug's heat range. That is the minimum and maximum temperatures
between which the plug will offer optimum performance.

The heat range of NGK Spark Plugs is wider than ordinary plugs therefore they are suitable for both high speed and low speed driving. Compared with conventional plugs of the same
pre-ignition rating they have more resistance to fouling.
Compared to ordinary plugs with equal anti-fouling resistance; NGK Spark Plugs have a higher pre-ignition rating.

NGK'S HEART OF COPPER
Copper wire used in place of the iron core in conventional plugs is the secret of NGK's Wide Heat Range. Copper's superior heat conductivity dissipates heat quicker. It cools the
electrode tip and insulator tip which prevents hot spots that could cause pre-ignition. Increased heat resistance does not affect fouling resistance; which is primarily determined by the insulator nose length. The longer the nose; the more susceptible it is to heat and the more free from fouling. By raising the pre-ignition rating with the high conduction copper and leaving the insulator nose long; NGK produces the Wide Range Plug. One that meets the broad thermal requirements of engines under high and low RPM conditions. With the exception of a couple of older applications all the spark plugs in this motorcycle catalogue employ copper core technology.

NGK

NGK is one of the largest manufacturers in the world of spark plugs and lambda sensors. All global motorcycle manufacturers use NGK products in their motorcycles.

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Packaging & Delivery

Delivery time scales are dependent on the order value and products ordered. For smaller items we use a Royal Mail service, for all other items a courier service would be used. Courier: Depending on the product & value, orders can sometimes take up to 5 to 7 working days. International orders would be sent using a 7-14 working day service. Tracking is available for most packages sent via a courier service, if tracking is available then your tracking number for your package is sent within your dispatch email. If your package doesn't arrive by the estimated timescale, please email us.