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Tech Tuesday: The Crankcase

Combustion in the combustion chamber acts on the piston with a pressure (force when multiplied by the piston head area) which generates a linear movement of the piston. This movement is then transformed into a rotating one since the piston is mounted on a reciprocating mechanism consisting of the crankshaft and conrod. The crankshaft rotates with the support of spherical bearings mounted in the crankcase referred to as the main bearings.

The force acting on the piston is transformed and transmitted through the conrod and crankshaft and must then be absorbed by the crankcase. The crankcase not only has to absorb these forces, it also has many other functions that make it an essential element of the engine. A fundamental role is to act as a pre-compression chamber. When the piston moves downwards in the cylinder, mixture is compressed and pushed into the transfer ducts, through the transfer ports and into the combustion chamber. In addition to this, the crankcase also has the function of being the bond between the engine’s different components such as the cylinder, crankshaft, carburettor, engine-chassis mount, ignition system and coil.

The material used to build the crankcases of modern 2-stroke competition engines, such as those used for karting purposes, is aluminium alloy, which reduces considerably the weight of the engine. Aluminium though has some weaknesses linked to the fact that it heats up more easily than cast iron and consequently deforms more. Its heating up generates a rise in temperature of the crankcase walls which consequently heats up the mixture in the crankcase. A fluid (mixture) that heats up increases in pressure and expands, reducing its density and the volumetric efficiency of the crankcase pump.

cfd147e3787c6d7dd095f8d08f117f8e
The Crankcasing houses the real guts of the motor

Temperature increases also generate expansion of the aluminium alloy and therefore the walls of the crankcase (they reach around 100°C). This expansion will be different in different areas of the crankcase since the component’s walls vary in thickness and also fresh mixture can act as more of a coolant in some areas than others. Consequently, the crankcase will deform and generate negative effects. For example, alignment between the two main bearings that carry the crankshaft can be lost. Gas sealing between the crankcase and cylinder can also become critical. Another important effect is that the perpendicularity of the cylinder’s axis to the crankshaft is at risk. Finally, main bearings can change the tightness of assembly of the roller balls inside the cages which can produce seizures and breaking of the cages.

The limited mechanical strength of light aluminium alloys from which crankcases are constructed also needs to be taken into account with regard to the threads of the holes for the holding down bolts and the cylinder head studs. To avoid rapid damage to the threads it is advisable for the effective threaded length to be not less than 2.5 times the diameter. Assistance can also be given by the insertion of steel threads that are much more resistant, especially when studs and bolts are frequently screwed and unscrewed. Since the crankcase working as a pump needs reduced internal volume to be effi cient, it is constructed of two halves symmetrical with respect to a vertical plane perpendicular to the axis of the crankshaft. When joined, the two halves must be completely gas tight and to do this a gasket is also positioned between the parts. Mixture loss would reduce the efficiency and performance of the engine.

rvz_01
The Crankcase houses the Gear box on shifters

To have good matching of the two symmetrical parts, production must be very precise. Cylindrical dowel pins also help couple the two elements. Sealing must also be obtained where the crankcase opens to permit the exit of the ends of the crankshaft. Oil seals are used on both sides and are rubber rings that have one or two ‘lips’ that seal the area around the crankshaft. The aim is to have good sealing but low friction loss generated by the ‘lips’ and the crankshaft that are in contact with one another. As already mentioned, the crankcase also has the role of absorbing all the forces transmitted by the crankshaft. To limit deformation of the crankcase it is built with ribbing all over its external surface. These ribs help both to strengthen the structure and to cool down the surfaces

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Tech Tuesday: The Crankcase

Combustion in the combustion chamber acts on the piston with a pressure (force when multiplied by the piston head area) which generates a linear movement of the piston. This movement is then transformed into a rotating one since the piston is mounted on a reciprocating mechanism consisting of the crankshaft and conrod. The crankshaft rotates with the support of spherical bearings mounted in the crankcase referred to as the main bearings.

The force acting on the piston is transformed and transmitted through the conrod and crankshaft and must then be absorbed by the crankcase. The crankcase not only has to absorb these forces, it also has many other functions that make it an essential element of the engine. A fundamental role is to act as a pre-compression chamber. When the piston moves downwards in the cylinder, mixture is compressed and pushed into the transfer ducts, through the transfer ports and into the combustion chamber. In addition to this, the crankcase also has the function of being the bond between the engine’s different components such as the cylinder, crankshaft, carburettor, engine-chassis mount, ignition system and coil.

The material used to build the crankcases of modern 2-stroke competition engines, such as those used for karting purposes, is aluminium alloy, which reduces considerably the weight of the engine. Aluminium though has some weaknesses linked to the fact that it heats up more easily than cast iron and consequently deforms more. Its heating up generates a rise in temperature of the crankcase walls which consequently heats up the mixture in the crankcase. A fluid (mixture) that heats up increases in pressure and expands, reducing its density and the volumetric efficiency of the crankcase pump.

cfd147e3787c6d7dd095f8d08f117f8e
The Crankcasing houses the real guts of the motor

Temperature increases also generate expansion of the aluminium alloy and therefore the walls of the crankcase (they reach around 100°C). This expansion will be different in different areas of the crankcase since the component’s walls vary in thickness and also fresh mixture can act as more of a coolant in some areas than others. Consequently, the crankcase will deform and generate negative effects. For example, alignment between the two main bearings that carry the crankshaft can be lost. Gas sealing between the crankcase and cylinder can also become critical. Another important effect is that the perpendicularity of the cylinder’s axis to the crankshaft is at risk. Finally, main bearings can change the tightness of assembly of the roller balls inside the cages which can produce seizures and breaking of the cages.

The limited mechanical strength of light aluminium alloys from which crankcases are constructed also needs to be taken into account with regard to the threads of the holes for the holding down bolts and the cylinder head studs. To avoid rapid damage to the threads it is advisable for the effective threaded length to be not less than 2.5 times the diameter. Assistance can also be given by the insertion of steel threads that are much more resistant, especially when studs and bolts are frequently screwed and unscrewed. Since the crankcase working as a pump needs reduced internal volume to be effi cient, it is constructed of two halves symmetrical with respect to a vertical plane perpendicular to the axis of the crankshaft. When joined, the two halves must be completely gas tight and to do this a gasket is also positioned between the parts. Mixture loss would reduce the efficiency and performance of the engine.

rvz_01
The Crankcase houses the Gear box on shifters

To have good matching of the two symmetrical parts, production must be very precise. Cylindrical dowel pins also help couple the two elements. Sealing must also be obtained where the crankcase opens to permit the exit of the ends of the crankshaft. Oil seals are used on both sides and are rubber rings that have one or two ‘lips’ that seal the area around the crankshaft. The aim is to have good sealing but low friction loss generated by the ‘lips’ and the crankshaft that are in contact with one another. As already mentioned, the crankcase also has the role of absorbing all the forces transmitted by the crankshaft. To limit deformation of the crankcase it is built with ribbing all over its external surface. These ribs help both to strengthen the structure and to cool down the surfaces

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Prepared to win: The military call it the 7p’s…

stock-joyner

I’ll paraphrase slightly as this is a family magazine and give you the 6p’s… Proper Planning and Preparation Prevents Poor Performance.

Top teams will tell you that races are won and lost in the workshop as often as they are on the track. Or to quote the other time-worn adage… To finish first, first you have to finish.

Working space

It’s all terribly exciting getting into karting, but calm down and stop for a minute. Even before you collect the kart, things need to be done that could affect the way things go for you ever onward. Set aside a working area. Ideally, this space is sacred with nothing else apart from karting stuff allowed there, but a garage or workshop that gets kept just for one purpose is a rare commodity indeed. However, an area with plenty of light and enough room to have the kart up on a stand and be able to walk around it easily is the minimum that you are aiming for. Once you have sorted this out, the working area needs to be kept clear of gardening tools, bicycles or any of the other paraphernalia that tends to build up. It doesn’t need to be laboratory hygienic but keeping the work area clean and tidy will make things far easier, as will having a rack or two for tools, parts removed and spares that aren’t needed all the time. Keep the floor tidy, the chances of dropping a vital spacer seems to increase in proportion to the amount of clutter on the floor. Now you can bring the kart home get it on the stand and get on with things.

Clean and green

We are assuming that your first kart is very likely to be pre-owned so the first thing that you need to do once you get it home is strip it down as far as your expertise allows and set about giving it a deep clean. Even if you have bought a brand new machine you should spend an evening or two giving it a thorough spanner check before use. Deep cleaning or spanner checking a kart after buying it serves a very useful purpose, as it familiarises you with your new machine and forces you to look closely at every part of it. No matter how careful you have been with your purchase you could be amazed at what you find once you start, better to tackle it now than at the first track session.

The deep clean needs to become part of your kart preparation routine, after getting back from any meeting (or practice session) your kart should be stripped (at least partially) and cleaned. This will also allow you to check for cracks, loose nuts and bolts and damaged component while you are at it.

An MSA scrutineer of my acquaintance tells me that he is still amazed and appalled that karts are presented for inspection dirty. He has in the past sent karts away to be cleaned before he was prepared to look at them. “A waste of my time and theirs” was how he described it. He also added that it was rare for him to find any safety issues on a clean kart but often found fundamental preparation errors on dirty machines, reasoning that if you can’t be bothered to clean your machine you won’t be bothered to spanner check it either.

Wet and dry Running in the wet is like having somebody with a high-pressure hose spraying water and abrasive paste at your kart. This filthy mixture will creep everywhere and manage to penetrate every orifice. As soon as you get home and before you collapse into your favourite armchair give the kart a thorough dousing with water dispersant spray (careful with the brake though) to keep rust at bay until you can clean things properly.

The proper way to deal with a kart that’s been out in the wet is to strip it to the bare frame and then re-build, cleaning everything as it is put back on. Why so fussy? Because if you don’t, the grit that has managed to penetrate everywhere will act like very effective grinding paste and everything will wear at a phenomenal rate, look at the sidepod fixings after a wet run and you’ll notice dirty little trails creeping along the chrome and paint. That’s a mixture of grit and worn away metal coming from the joints. Leave the grit there and it will continue to nibble at the fixings as the kart flexes.

Nuts

Anybody who is serious about preparing their kart properly should consider that the Nyloc nuts are for one use only. However, on some less critical applications I will use Nyloc nuts a couple of times. The nuts are fitted plain for their first use and if I have occasion to remove them they are put back on with the addition of a blob of yellow paint on the nut. I then know that any nuts that have this blob of paint are on their second use and should be replaced if removed again.

Find your local fasteners stockists and buy at least 200 of each of the Nylock nuts you use (usually M6 and M8) then there is no excuse not to replace nuts after one use. While you are at it invest in a couple of bags of plain washers too.

One man, one job It’s great having a few mates over to help you prepare a kart but it can lead to problems, it might seem officious but if a
group of you are working on the machine allocate jobs to each person and make them totally responsible for that task. Get a couple of people on one task and there is always the chance of the “I thought that you had checked it” scenario. Make sure that each specific task is completed before you pack up; leaving a job in the middle is asking for trouble, if it can’t be avoided make a note of where you have got to and what needs to be done before the task is completed. Top tip… A whiteboard and a dry marker pen will pay back their cost many times over.

Ultimate responsibility

Somebody needs to take overall responsibility for all the final checks. That’s you!

Not on Friday night

If you need to be up bright and early on Saturday morning ready to travel to the meeting, Friday night isn’t the time to be spanner checking your kart ready for the weekend’s racing. Not only does it make the evening potentially fraught when you should be relaxing, it doesn’t leave any safety margin. Better to be doing the final checks on a Wednesday evening at the very latest, working on the theory that if you find anything that needs attention or worse still needs replacing you’ve still got a couple of days to get it ordered, delivered and fitted.

Spares box

A tough plastic box is ideal to stack with all the odds and sods that you are going to need for the weekend. Keeping a spares box stocked with all the essentials that you might need during a meeting ready packed and ready to go will save a huge amount of time when loading.

What do you pack? The short answer is anything that you imagine that you might need at the track. Trusting that the trackside kart shop will have what you need in stock isn’t the way to go.

To get you started… Spare chain or chains, if the amount of adjustment on your engine is limited and you need differing lengths to accommodate larger or smaller rear sprockets. Then there are the sprockets themselves. A box of nuts and bolts of a few different lengths, in the sizes used on your kart is always useful, as is a big bag of zip ties and a roll of gaffer tape, chain lube, spark plugs. Don’t forget the spare hubs if you use different lengths for different conditions. The list goes on, only you know what you really need. So grab a cup of tea, sit down with paper and pen and make your own list.

Wet tyres and rims need to be bagged up ready to use, keeping them in a bag serves a double purpose, it keeps them together and makes them easy to transport while excluding the light which is one of the things that degrades rubber. When you get home from the track, make one of the first jobs you do the replacement of any parts that you took from the box during the meeting, this way you won’t be caught short next time.

Tool time

Although some karters take a huge tool chest containing a mini work-shop full of stuff for those just-in-case moments this isn’t strictly necessary. However, having a small easily portable box containing essential tools is a must. It makes sense to have at least two separate compartments, one for the tools that you will be using all the time like the plug spanner (you might need to grab these fast) and the other for
the tools that might be used but probably won’t. Some even go to the length of having one set of tools for when they are at the track and another set of workshop tools; it all depends upon your budget.

Sensitive souls As karting becomes more complex the equipment to run them becomes similarly advanced. If you have invested in things
like set-up lasers and timing gear it would be foolhardy not to buy some proper hard cases with padded internals to protect them. The all important tyre pressure gauge needs to be packed separately too, to keep it safe from knocks that might harm its accuracy. Also think about where they and other expensive items like crash helmets will be kept, these need to be both safe from harm and away from prying eyes.
It’s an unpleasant thought but these are easy to steal, getting several hundred quids worth of kit nicked will sour even the most successful day’s racing.

Packing your van or trailer

There is huge wisdom in the saying “a place for everything and everything in its place”. Taking some time to do a trial pack of the van or trailer and work out where everything should go will pay dividends in the long-run. When you are happy that everything is in and the weight is balanced, then develop some sort of securing system for them. I’ve seen everything from light ratchet straps fastened in place to clever over-centre catches allowing boxes to be clipped into position in a few seconds. Merely chucking everything in and hoping for the best won’t do. Imagine if you have an accident on the way to the circuit, nobody wants to be hit in the back of the head by an unsecured tool box or have their entire spares stock strewn across the motorway.

Strapping a kart down securely can be a nightmare. Some teams always carry theirs stood up on end and fastened to the van sides, others park them flat. Either way they need to be held in such a way that they can’t jiggle around and bash into things, or for fixed gear karts snatch at the chain which is bad for the motor. Nor must they have pressure from the fixing straps on anything vital. One of the most elegant solutions I have seen to carrying a kart flat was in a trailer. This had a set of four U-shaped blocks fixed to the floor. The kart wheels dropped into the blocks and straps went over the tyres. Once secured this kart couldn’t move and there were no fastenings chafing or pulling at the chassis.

It’s only a mistake if you make it twice Inevitably you will discover that you have left something that’s needed at the circuit at home. Learn from this and make a note of what was forgotten. Do remember to do something about it when you get home though! Buy the book
Buy several pens, a good hard-backed notebook and one of Karting magazine’s set-up data books (c’mon we had to get a plug in somewhere!) and keep them all with your kit. In the set-up book note and record everything from the date, circuit and weather conditions to tyre pressures,
sprocket choice, lap times etc. In the hardback book record all the other stuff, for instance what you have forgotten to bring or parts used from the spares stock. Keep them safe, these will become your karting bibles.

Home again

Even if you get home at midnight, tired and dirty, kart clothing will need bringing in and unpacking so that it can dry and air, a sweaty helmet after 24 hours in its bag, eugh! If you are confident that the rest can be left safely without unpacking by all means do so, but don’t forget to waft the water dispersant spray over the kart if it’s been wet, overnight can be long enough for rust to take hold on unprotected components.
When you do unpack make it your rule that nothing is put away damp or dirty. If you do it is almost guaranteed you’ll forget something until the next time it’s time to use it, then it’ll be too late.

Categories
Features Features Features Features Features Features Features Features

Prepared to win: The military call it the 7p’s…

stock-joyner

I’ll paraphrase slightly as this is a family magazine and give you the 6p’s… Proper Planning and Preparation Prevents Poor Performance.

Top teams will tell you that races are won and lost in the workshop as often as they are on the track. Or to quote the other time-worn adage… To finish first, first you have to finish.

Working space

It’s all terribly exciting getting into karting, but calm down and stop for a minute. Even before you collect the kart, things need to be done that could affect the way things go for you ever onward. Set aside a working area. Ideally, this space is sacred with nothing else apart from karting stuff allowed there, but a garage or workshop that gets kept just for one purpose is a rare commodity indeed. However, an area with plenty of light and enough room to have the kart up on a stand and be able to walk around it easily is the minimum that you are aiming for. Once you have sorted this out, the working area needs to be kept clear of gardening tools, bicycles or any of the other paraphernalia that tends to build up. It doesn’t need to be laboratory hygienic but keeping the work area clean and tidy will make things far easier, as will having a rack or two for tools, parts removed and spares that aren’t needed all the time. Keep the floor tidy, the chances of dropping a vital spacer seems to increase in proportion to the amount of clutter on the floor. Now you can bring the kart home get it on the stand and get on with things.

Clean and green

We are assuming that your first kart is very likely to be pre-owned so the first thing that you need to do once you get it home is strip it down as far as your expertise allows and set about giving it a deep clean. Even if you have bought a brand new machine you should spend an evening or two giving it a thorough spanner check before use. Deep cleaning or spanner checking a kart after buying it serves a very useful purpose, as it familiarises you with your new machine and forces you to look closely at every part of it. No matter how careful you have been with your purchase you could be amazed at what you find once you start, better to tackle it now than at the first track session.

The deep clean needs to become part of your kart preparation routine, after getting back from any meeting (or practice session) your kart should be stripped (at least partially) and cleaned. This will also allow you to check for cracks, loose nuts and bolts and damaged component while you are at it.

An MSA scrutineer of my acquaintance tells me that he is still amazed and appalled that karts are presented for inspection dirty. He has in the past sent karts away to be cleaned before he was prepared to look at them. “A waste of my time and theirs” was how he described it. He also added that it was rare for him to find any safety issues on a clean kart but often found fundamental preparation errors on dirty machines, reasoning that if you can’t be bothered to clean your machine you won’t be bothered to spanner check it either.

Wet and dry Running in the wet is like having somebody with a high-pressure hose spraying water and abrasive paste at your kart. This filthy mixture will creep everywhere and manage to penetrate every orifice. As soon as you get home and before you collapse into your favourite armchair give the kart a thorough dousing with water dispersant spray (careful with the brake though) to keep rust at bay until you can clean things properly.

The proper way to deal with a kart that’s been out in the wet is to strip it to the bare frame and then re-build, cleaning everything as it is put back on. Why so fussy? Because if you don’t, the grit that has managed to penetrate everywhere will act like very effective grinding paste and everything will wear at a phenomenal rate, look at the sidepod fixings after a wet run and you’ll notice dirty little trails creeping along the chrome and paint. That’s a mixture of grit and worn away metal coming from the joints. Leave the grit there and it will continue to nibble at the fixings as the kart flexes.

Nuts

Anybody who is serious about preparing their kart properly should consider that the Nyloc nuts are for one use only. However, on some less critical applications I will use Nyloc nuts a couple of times. The nuts are fitted plain for their first use and if I have occasion to remove them they are put back on with the addition of a blob of yellow paint on the nut. I then know that any nuts that have this blob of paint are on their second use and should be replaced if removed again.

Find your local fasteners stockists and buy at least 200 of each of the Nylock nuts you use (usually M6 and M8) then there is no excuse not to replace nuts after one use. While you are at it invest in a couple of bags of plain washers too.

One man, one job It’s great having a few mates over to help you prepare a kart but it can lead to problems, it might seem officious but if a
group of you are working on the machine allocate jobs to each person and make them totally responsible for that task. Get a couple of people on one task and there is always the chance of the “I thought that you had checked it” scenario. Make sure that each specific task is completed before you pack up; leaving a job in the middle is asking for trouble, if it can’t be avoided make a note of where you have got to and what needs to be done before the task is completed. Top tip… A whiteboard and a dry marker pen will pay back their cost many times over.

Ultimate responsibility

Somebody needs to take overall responsibility for all the final checks. That’s you!

Not on Friday night

If you need to be up bright and early on Saturday morning ready to travel to the meeting, Friday night isn’t the time to be spanner checking your kart ready for the weekend’s racing. Not only does it make the evening potentially fraught when you should be relaxing, it doesn’t leave any safety margin. Better to be doing the final checks on a Wednesday evening at the very latest, working on the theory that if you find anything that needs attention or worse still needs replacing you’ve still got a couple of days to get it ordered, delivered and fitted.

Spares box

A tough plastic box is ideal to stack with all the odds and sods that you are going to need for the weekend. Keeping a spares box stocked with all the essentials that you might need during a meeting ready packed and ready to go will save a huge amount of time when loading.

What do you pack? The short answer is anything that you imagine that you might need at the track. Trusting that the trackside kart shop will have what you need in stock isn’t the way to go.

To get you started… Spare chain or chains, if the amount of adjustment on your engine is limited and you need differing lengths to accommodate larger or smaller rear sprockets. Then there are the sprockets themselves. A box of nuts and bolts of a few different lengths, in the sizes used on your kart is always useful, as is a big bag of zip ties and a roll of gaffer tape, chain lube, spark plugs. Don’t forget the spare hubs if you use different lengths for different conditions. The list goes on, only you know what you really need. So grab a cup of tea, sit down with paper and pen and make your own list.

Wet tyres and rims need to be bagged up ready to use, keeping them in a bag serves a double purpose, it keeps them together and makes them easy to transport while excluding the light which is one of the things that degrades rubber. When you get home from the track, make one of the first jobs you do the replacement of any parts that you took from the box during the meeting, this way you won’t be caught short next time.

Tool time

Although some karters take a huge tool chest containing a mini work-shop full of stuff for those just-in-case moments this isn’t strictly necessary. However, having a small easily portable box containing essential tools is a must. It makes sense to have at least two separate compartments, one for the tools that you will be using all the time like the plug spanner (you might need to grab these fast) and the other for
the tools that might be used but probably won’t. Some even go to the length of having one set of tools for when they are at the track and another set of workshop tools; it all depends upon your budget.

Sensitive souls As karting becomes more complex the equipment to run them becomes similarly advanced. If you have invested in things
like set-up lasers and timing gear it would be foolhardy not to buy some proper hard cases with padded internals to protect them. The all important tyre pressure gauge needs to be packed separately too, to keep it safe from knocks that might harm its accuracy. Also think about where they and other expensive items like crash helmets will be kept, these need to be both safe from harm and away from prying eyes.
It’s an unpleasant thought but these are easy to steal, getting several hundred quids worth of kit nicked will sour even the most successful day’s racing.

Packing your van or trailer

There is huge wisdom in the saying “a place for everything and everything in its place”. Taking some time to do a trial pack of the van or trailer and work out where everything should go will pay dividends in the long-run. When you are happy that everything is in and the weight is balanced, then develop some sort of securing system for them. I’ve seen everything from light ratchet straps fastened in place to clever over-centre catches allowing boxes to be clipped into position in a few seconds. Merely chucking everything in and hoping for the best won’t do. Imagine if you have an accident on the way to the circuit, nobody wants to be hit in the back of the head by an unsecured tool box or have their entire spares stock strewn across the motorway.

Strapping a kart down securely can be a nightmare. Some teams always carry theirs stood up on end and fastened to the van sides, others park them flat. Either way they need to be held in such a way that they can’t jiggle around and bash into things, or for fixed gear karts snatch at the chain which is bad for the motor. Nor must they have pressure from the fixing straps on anything vital. One of the most elegant solutions I have seen to carrying a kart flat was in a trailer. This had a set of four U-shaped blocks fixed to the floor. The kart wheels dropped into the blocks and straps went over the tyres. Once secured this kart couldn’t move and there were no fastenings chafing or pulling at the chassis.

It’s only a mistake if you make it twice Inevitably you will discover that you have left something that’s needed at the circuit at home. Learn from this and make a note of what was forgotten. Do remember to do something about it when you get home though! Buy the book
Buy several pens, a good hard-backed notebook and one of Karting magazine’s set-up data books (c’mon we had to get a plug in somewhere!) and keep them all with your kit. In the set-up book note and record everything from the date, circuit and weather conditions to tyre pressures,
sprocket choice, lap times etc. In the hardback book record all the other stuff, for instance what you have forgotten to bring or parts used from the spares stock. Keep them safe, these will become your karting bibles.

Home again

Even if you get home at midnight, tired and dirty, kart clothing will need bringing in and unpacking so that it can dry and air, a sweaty helmet after 24 hours in its bag, eugh! If you are confident that the rest can be left safely without unpacking by all means do so, but don’t forget to waft the water dispersant spray over the kart if it’s been wet, overnight can be long enough for rust to take hold on unprotected components.
When you do unpack make it your rule that nothing is put away damp or dirty. If you do it is almost guaranteed you’ll forget something until the next time it’s time to use it, then it’ll be too late.

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Female Focus: Does Sexism Still Exist in Karting?

Stock-Girls

As I mentioned briefly in my first article karting is an incredibly unique sport. It is one of very few activities out there that lets us females and males compete against each other on a level playing fi eld. Motorsport began as primarily a male dominated arena where males would flaunt their new vehicles and take part in lengthy ‘staged time trials’ around main roads.

The first time women were introduced into this exclusive fold was when the chaps decided they were worthy of sitting in the passenger seat and giving directions, although I do wonder if there were many arguments over whose fault it was for missing the left turn ahead. However, now it’s a completely different story altogether with women such as Danica Patrick in the forefront of NASCAR racing. Perhaps because of the increase in women succeeding and dominating in the higher ranks of motorsport this is spurring on more females to step into racing.

I remember my first experience of the karting world aged nine. Like many others I started off at what I originally believed to be the largest kart circuit in Essex. However I was soon to fi nd out that this ‘epic’ 250 metre track was probably about the same length as the straight at Kimbolton! After being shown the ropes for a while I was ready to go. Obviously on my first go out I spun… a lot, and I hadn’t quite grasped the concept of needing to brake for a corner. Nonetheless I was enjoying myself and that’s all that matters right? Well, apparently not. Once I’d had my little ‘test session’, seven other arrive-and-drive racers were let out on the track, all boys. I was determined to prove I knew what I was doing.

In the end I turned out to be faster than them. Expecting some kind of warm welcome I greeted them and was told that, “Girls aren’t meant to come here, go and buy a doll’s house”. Fortunately I saw the funny side, and decided from that point onward I would make it my aim to continue to prove my worth in this male dominated sport.

In the eleven years I’ve been racing I have come across some nasty stereotypical insults about my driving, but as I’ve matured I’ve grown to ignore it and realise the best way to silence a chauvinistic pig is to just go out and there and beat him! Having said this, I wouldn’t do karting if I didn’t enjoy it, and I’d say the majority of the males I race or have raced with have no issues with me being a female, and because of this we have a mutual respect for one another. I’ve made some amazing friends over the years. This, however, is merely my view and my experience, so I headed down to my local track (Shenington) to find some male and female karters and see what their views were on this whole issue. Fortunately I found two willing male and female participants, Dean Patrick and Sarah Drew, and decided to interrogate them. They both race Junior Rotax, but only at Shenington club rounds.

How long have you guys been racing? Have you experienced any hostility from other racers in this time?Dean: I’ve been competing since I was 10 and when I first started I was quite nervous and felt the guys with painted lids were like Gods or something. I’d literally let them past, and when I started getting good they didn’t like it. That’s the only hostility I’ve ever had.

Sarah: I’ve only been racing for three years, since I was 12. I think a lot of people welcomed me after I’d been doing it for a while, but to start with I don’t think the guys liked the fact I was there because we were all young and a bit immature. I remember getting knocked off the track a lot at the beginning.

Dean, what are your views on ‘girl racers’?

Dean: Personally I’ve never had a problem with it, although I can see why some guys get frustrated when a girl is quicker than them because other racers could tease them. It’s probably harder I think for girls to gain respect on the track, because I know a lot of guys that aren’t that quick and still don’t get punted around as much as some girls I know. Motorsport is seen as a male thing, but so many girls do it now it shouldn’t be an issue any more.

What do you think, if anything, could be altered to change some people’s attitudes?
Sarah: I don’t think anything in the sport itself could be altered as it’s all down to the person’s views. I think it’s encouraging for girls to see loads of other women competing and winning in motorsport.

Dean: Like Sarah said, it’s hard to change a person’s opinion. I think karting is a great sport and, compared to a lot of others, people are more open and accepting to girls. If a guy can’t handle a girl beating him then he probably shouldn’t be racing! Sexism in any sport is always going to be a tough issue. In the 21st century we’d like to think it would be non-existent by now and we’d all be holding hands under a rainbow. However, despite the distinct lack of any rainbow, once you have your helmet on it doesn’t matter who you are. Just what you can do.

Categories
Features Features Features Features Features Features Features Features

Female Focus: Does Sexism Still Exist in Karting?

Stock-Girls

As I mentioned briefly in my first article karting is an incredibly unique sport. It is one of very few activities out there that lets us females and males compete against each other on a level playing fi eld. Motorsport began as primarily a male dominated arena where males would flaunt their new vehicles and take part in lengthy ‘staged time trials’ around main roads.

The first time women were introduced into this exclusive fold was when the chaps decided they were worthy of sitting in the passenger seat and giving directions, although I do wonder if there were many arguments over whose fault it was for missing the left turn ahead. However, now it’s a completely different story altogether with women such as Danica Patrick in the forefront of NASCAR racing. Perhaps because of the increase in women succeeding and dominating in the higher ranks of motorsport this is spurring on more females to step into racing.

I remember my first experience of the karting world aged nine. Like many others I started off at what I originally believed to be the largest kart circuit in Essex. However I was soon to fi nd out that this ‘epic’ 250 metre track was probably about the same length as the straight at Kimbolton! After being shown the ropes for a while I was ready to go. Obviously on my first go out I spun… a lot, and I hadn’t quite grasped the concept of needing to brake for a corner. Nonetheless I was enjoying myself and that’s all that matters right? Well, apparently not. Once I’d had my little ‘test session’, seven other arrive-and-drive racers were let out on the track, all boys. I was determined to prove I knew what I was doing.

In the end I turned out to be faster than them. Expecting some kind of warm welcome I greeted them and was told that, “Girls aren’t meant to come here, go and buy a doll’s house”. Fortunately I saw the funny side, and decided from that point onward I would make it my aim to continue to prove my worth in this male dominated sport.

In the eleven years I’ve been racing I have come across some nasty stereotypical insults about my driving, but as I’ve matured I’ve grown to ignore it and realise the best way to silence a chauvinistic pig is to just go out and there and beat him! Having said this, I wouldn’t do karting if I didn’t enjoy it, and I’d say the majority of the males I race or have raced with have no issues with me being a female, and because of this we have a mutual respect for one another. I’ve made some amazing friends over the years. This, however, is merely my view and my experience, so I headed down to my local track (Shenington) to find some male and female karters and see what their views were on this whole issue. Fortunately I found two willing male and female participants, Dean Patrick and Sarah Drew, and decided to interrogate them. They both race Junior Rotax, but only at Shenington club rounds.

How long have you guys been racing? Have you experienced any hostility from other racers in this time?Dean: I’ve been competing since I was 10 and when I first started I was quite nervous and felt the guys with painted lids were like Gods or something. I’d literally let them past, and when I started getting good they didn’t like it. That’s the only hostility I’ve ever had.

Sarah: I’ve only been racing for three years, since I was 12. I think a lot of people welcomed me after I’d been doing it for a while, but to start with I don’t think the guys liked the fact I was there because we were all young and a bit immature. I remember getting knocked off the track a lot at the beginning.

Dean, what are your views on ‘girl racers’?

Dean: Personally I’ve never had a problem with it, although I can see why some guys get frustrated when a girl is quicker than them because other racers could tease them. It’s probably harder I think for girls to gain respect on the track, because I know a lot of guys that aren’t that quick and still don’t get punted around as much as some girls I know. Motorsport is seen as a male thing, but so many girls do it now it shouldn’t be an issue any more.

What do you think, if anything, could be altered to change some people’s attitudes?
Sarah: I don’t think anything in the sport itself could be altered as it’s all down to the person’s views. I think it’s encouraging for girls to see loads of other women competing and winning in motorsport.

Dean: Like Sarah said, it’s hard to change a person’s opinion. I think karting is a great sport and, compared to a lot of others, people are more open and accepting to girls. If a guy can’t handle a girl beating him then he probably shouldn’t be racing! Sexism in any sport is always going to be a tough issue. In the 21st century we’d like to think it would be non-existent by now and we’d all be holding hands under a rainbow. However, despite the distinct lack of any rainbow, once you have your helmet on it doesn’t matter who you are. Just what you can do.

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Tech Talk: Transmission Ratio

Stock-Old

Transmission ratio is determined by the gears of the engine and the rear and front sprocket. In KF classes only front and rear sprocket act on transmission ratio.

What happens is that torque generated by the engine on the crank-shaft acts on front sprocket. Since torque is equivalent to a force multiplied by a length we can consider the force (Ffs) acting on the rear sprocket teeth tangent to the sprocket equal to: Ffs = Tcs / Rfs, (1) with Tcs the torque on crank-shaft and Rfs is the radius of the front sprocket.

Now the same force Ffs acts along the chain to the rear sprocket. So torque produced on rear sprocket is: Tra = Ffs · Rrs, (2) with Rrs the radius of the rear sprocket. The torque acting on the rear axle is just the same of course and so is the torque on rear tires. So the force acting horizontally on the tire print in the direction in which the kart accelerates: Fra = Ffs · Rrs/Rrt, (3) With Rrt the radius of rear tires. This means that the greater the radius Rrs of the rear sprocket and the greater the force Fra moving the kart forward.

The opposite situation is generated by the front sprocket. In fact substituting equation (1) in (3) leads to: Fra = Tcs/Rfs · Rrs/Rrt, Which means that the greater the radius of the front sprocket (number of teeth) and the lower the value of the force moving the kart. The conclusion is that if we increase the number of teeth of the front sprocket we will have lower acceleration of the kart, but we will be able to use the torque for a greater range of speed, instead we will have the opposite result with less teeth.

With greater teeth of rear sprocket we will instead have more acceleration of the kart for a smaller range of speed and vice versa for a lower number of teeth. It is also interesting to notice how much tire radius (Rrt) also effects transmission ratio. Such radius must be measure when changing tires, but also we should also consider that tire wear leads to lower tire radius and so transmission ratio can also change because of rubber coming off the tire print surface.