Seats

Having the right seat is a combination of comfort and safety.  It is important to get a seat that fits snugly, but not tightly around the driver's hips.  The height of the back should extend up to the driver's shoulders, but not so high that it touches the driver's neck brace. If the back of the seat pushes on the driver's neck brace or helmet, it can be very uncomfortable and even unsafe.

After selecting the seat, get ready to mount it to the chassis.  Place the chassis on a flat surface or on your kart stand.  Your goal is to mount the bottom of the seat level with the bottom of the chassis rails. If it is any lower, it could become damaged by the items on the road.

Use a board between the kart frame and the stand or trolley to position the seat.  Put the seat on the board and place a heavy object in the seat so that it sits flat.  The front edge measurement is taken from between the furthes forward edge of the seat and the front chassis tube which is where the driver's heel would rest.  This dimension will vary according to the seat shape and size though it should be approximately 61- 62 cm.  Measuring perpendicular from the spine on the back of the seat to the middle of the rear axle, the distance should be 17 cm.  The seat should sit in the middle of the seat supports. 

Once the seat is in position, it is time to start marking holes. Before marking the holes, bend the tabs of the seat stays so that the flat of the stays are parallel to the sides of seat. Place nylon seat washers on the stays and then mark the mounting points on the seat.  Drill the 4 holes in the front and mount the seat. Again, bend the tabs of the rear seat stays, place the nylon washers on the stays, and mark the holes.  Drill the holes and insert the bolts. 

It is vital that the bolts slide cleanly straight through the seat and the stays without any pressure or twisting on the seat.  If it takes pressure to correct the alignment of the bolt holes in the seat and the holes in the stays, you need to restart the alignment and drilling process. Misalignment pressure on the seat, can cause it to crack during the rigors of racing.

There is a detailed description, along with videos at http://www.kartpartsdepot.com/product_p/030.htm

The Off-Season

The weather has been pretty rough in the north, but racing is already starting up in the southern climates. We are jealous, to say the least.

Even if we cannot start racing yet, it is a good time to look at our karts for off-season maintenance. Scouring the web, there are a number of pretty good checklists for what needs to be done regularly, though experienced karters probably have lists of their own. All of these items are in addition to the normal things you would do between races to make sure your kart is in peak condition.

The off-season is a good time to remove body kits and bumpers and inspect for damage. If there is anything too bad to repair, this will give you time to replace them.

 Remove wheels and tires to look for bent rims. Next, remove the rear axle and clean and check the axle bearings. Check brake rotors and calipers for cracks. Clean brake pads. Remove the brake master cylinder and brake lines. Replace parts that old or visibly worn. Check the hub and sprockets and replace any bent sprockets.

Finally, inspect the chassis for any defects or wear. Make sure the seat mounts and bumper mounts are tight. Look carefully around the engine mount area for any cracks. Repair any defects and then clean or repaint the chassis. As you reassemble your kart, check for bent or cross-threaded bolts and torque them to correct specs.

Performing off-season maintenance will not make the cold weather go away, but will get you ready to hit the track on that first nice day. 

Helmets

The most important part of the go kart is the driver, and the most important part of the driver’s gear is the helmet.

According to the Consumer Products Safety Commission, go kart helmets must meet DOT FMVSS 218 or Snell M-2005 the same as motocross (M is for motorcyle), or Snell K-78 (K for Karting). In addition, Snell SA-2000 is also accepted (SA for specialty automotive or car racing) in IKF kart racing. Full coverage helmets are recommended and different karting association also have their own rules so serious racers must consider these as well. See table below, courtesy of floridawintertour.com.

Make sure the helmet fits. The Snell Memorial Foundation recommends the following procedure for testing fit: Position the helmet on your head so that it sits low on your forehead; if you can't see the edge of the brim at the extreme upper range of your vision, the helmet is probably out of place. Adjust the retention system so that when in use, it will hold the helmet firmly in place. This positioning and adjusting should be repeated to obtain the very best result possible. Try to remove the helmet without undoing the retention system closures. If the helmet comes off or shifts over your eyes, readjust and try again. If no adjustment seems to work, this helmet is not for you; try another.

Consider weight. The weight of the helmet adds to the weight of the head and the g-forces that are felt during racing. Lighter weight materials tend to be more expensive, so it is necessary to balance that with your budget. As long as the helmet fits properly, select the lightest one that you can afford.

Replace it. Once a helmet has been in a crash, it should be replaced. If you are lucky enough to go for a long time without a crash, then watch it for wear. Check the fit occasionally to be sure that the internal padding and structure of the helmet has not degraded due to sweat, cleaning, or general wear.

CIK

A helmet with an efficient and unbreakable protection for the eyes. Helmets must comply with the following prescriptions:

For Drivers under 15 years old:	- Snell-FIA CMH (Snell-FIA CMS2007 and Snell-FIA CMR2007)
For Drivers over 15 years old:	- Snell Foundation K98, SA2000, K2005, SA2005, K2010, SA2010 and SAH 2010 (USA) - British Standards Institution A-type and A/FR-type BS6658-85, including any amendments (GBR) - FIA 8860-2004 and FIA 8860-210 (FRA) - SFI Foundation Inc., Spec. SFI 31.1A and 31.2A (USA) - Snell-FIA CMH (Snell-FIA CMS2007 and Snell-FIA CMR2007)

WKA

Snell Foundation Specifications	Legal Until
SA and M 2005	12/20/2016 - Go-Karts and Champ Karts
K 2005	12/20/2016 - Go-Karts and Champ Karts
CMS 2007 (Youth Helmet)	12/20/2016 - Go-Karts and Champ Karts
CMR 2007 (Youth Helmet)	12/20/2016 - Go-Karts and Champ Karts
M 2010	12/20/2021 - Go-Karts only; not Champ Karts
SA 2010	12/20/2021 - Go-Karts and Champ Karts
SFI Specifications	Legal Until
24.1 (Youth Helmet)	12/20/2016 - Go-Karts and Champ Karts
31.2a	12/20/2016 - Go-Karts and Champ Karts
41.2a	12/20/2016 - Go-Karts and Champ Karts
24.1/2005 (Youth Helmet)	12/20/2016 - Go-Karts and Champ Karts
31.1/2005	12/20/2016 - Go-Karts and Champ Karts
41.1/2005	12/20/2016 - Go-Karts and Champ Karts
24.1/2010 (Youth Helmet)	12/20/2021 - Go-Karts and Champ Karts
31.1/2010	12/20/2021 - Go-Karts and Champ Karts
41.1/2010	12/20/2021 - Go-Karts only; not Champ Karts

Tires - part 2

Kart tire sizes are stated differently than other types of tires and sometimes even vary across manufacturers.  Regardless of the tire manufacturer, you will see three numbers:

A.  Tread width

B.  Overall diameter

C.  Rim diameter

Typically, this is shown as BxA-C so a tire that is 10 x 4.5 - 5 would be 10 inches in diameter overall, 4.5 inches wide, and have a rim that is 5 inches across.  Bridgestone tires give sizes as A/B-C and Burris tires has a numbering system shown as B-A-C.  To learn more about the wheel sizes, and making correct wheel selections for your kart, visit our web page at http://www.kartpartsdepot.com/Go_Kart_Wheels_s/1850.htm

Karters understand the challenge or maintaining consistent lap times and outside of the driver, the largest impact will come from the tires.  But instead of making sure the tires are always the same, lap times are best maintained and improved when tires are adjusted to machine and driving conditions.

Manufacturer recommended tire pressure is usually given as a range.  While it is not recommended to go outside this range, where tires are run within the range is dependent on personal preference and the weather and track conditions.  

Temperature – lower the pressure slightly as the temperature rises to maintain the grip on the track.

Road surface – lower the pressure slightly when there is lots of rubber residue on the track.

Wet conditions – switch to wet tires and switch back to slicks as soon as possible.  If you can’t get back to the slicks as the track dries out, lower the pressure in the tires to get better grip.

When should you replace your tires?

A good indicator is the kart itself.  When tires need to be replaced, the kart may not feel as smooth or controlled around the corners as it does not grip the track as well. 

For car tires, the easy rule is to place a penny in the tread and use Lincoln’s chin as a tread wear indicator.  That obviously does not work on slicks like on automobile tires, so many kart tires come with small holes in the tread to indicate how much rubber has worn off.  If your tires have this indicator, pay attention to it, because it will tell you when it is time for some new tires.

Tires - part 1

One of the most important components on a kart is the tire.  Tires impact the handling and the speed of the cart directly and need to be selected based on a variety of factors.  Most kart racers have a variety of tires to suit the elements on the day of racing because if you race go karts and want to win, understanding tires is one of the most important criteria for being successful.

 

Tread:

Slicks – These tires have absolutely no tread on them and are used for racing on a paved tracks.

Treaded tires – These tires resemble car tires with normal looking treads.  They do not grip the track as well as slicks, but provide a mechanism for water to be pushed away if you are on a wet surface.

Knobby or studded tires - These tires are used in off-road environments where the cart needs to handle well on very rough dirt and uneven surfaces because they grip better.

Sidewall:

Stiff – if you are racing on a paved track, you want stiff sidewalls to prevent the tire from bending when you corner.

Soft – if you are racing on very rough terrain, a softer sidewall will help provide some cushion and allow the tire to conform to the uneven racing surface providing more grip.

Size:

Some karts will use smaller tires up front to make it easier to steer.  The diameters are the same, but the widths are typically different.    For racing on an oval track, tires are typically different sizes on left and right.

Tire pressure is extremely important.  Make sure all tires are properly inflated (within the manufacturer specified range) each time you go out.  Underinflated or overinflated tires will not wear as well so you will reduce the life of the tires.  Tires improperly inflated can also cause stability problems because they will not have the proper shape.  More about this next time.

The Chassis - the Structure of the Kart

Every kart begins with a good chassis.  Kart chassis are made of steel tube and have no separate suspension system.  The chassis must be stiff enough to support the forces from the weight of the cart and the rider during turns, but still be flexible enough to work as a suspension, flexing and moving as the kart goes around the track. 

There are different kinds of chassis for the different kinds of racing.  An offset chassis is used for left-turn-only speedway racing so the driver sits on the left side of the kart. A straight chassis places the driver in the center and is used for sprint racing.  Caged karts have a roll cage surrounding the driver. These will be found at some indoor rental locations as well as dirt tracks. Open karts have no roll cage.

Some kart chassis will accommodate stiffening bars at the rear, front, and side so that the driver can alter the stiffness of the chassis. Adjusting the stiffness of the chassis provides different handling for different track conditions.  A more flexible chassis will perform better in wet conditions and a stiffer chassis is better for a dry track.  The side pod bars on the kart will have the biggest impact on the stiffness of the chassis so if you are looking to make big adjustments, go there first.

Racing - The Starting Line

There are many different racing disciplines including the Formula racing, Stock cars, Touring cars, Rallying, and Drag racing.  For many of those racing styles, kart racing is the first step on the career ladder. 

Karts are constructed with a small, flat chassis, relatively small wheels, a small two-cycle or four-cycle engine, and almost no body work.  There is a large rental market of indoor and outdoor tracks for drivers to try different karts and perfect their driving skills without investing in their own equipment.  

Sprint karting tracks are less than one mile in length and have many corners.  Some also have elevation changes to go along with sharp and wide turns, and long and short straightaways.  Indoor tracks tend to be smaller and tighter, but some outdoor circuits can be set up to provide similar technical challenges.

Even within karting, there is lots of variation.  To illustrate that, I have included the World Karting Association’s racing quick guide here. 

Happy racing.

WKA Kart Racing Quick Guide
Chassis Style	Engine	WKA National Series
Oval-track (driver left offset)	4-cycle Box Stock (Clone)	Speedway Dirt, Speedway Pavement
Oval-track (driver left offset)	4-cycle Animal	Speedway Dirt, Speedway Pavement
Oval-track (driver left offset)	4-cycle Flathead	Speedway Dirt, Speedway Pavement
Oval-track (driver left offset)	2-cycle Unlimited	Speedway Dirt
Sprint	2-cycle TaG	Manufacturers Cup
Sprint	2-cycle Yamaha	Manufacturers Cup
Sprint	2-cycle Komet (KPV)	Manufacturers Cup
Sprint	2-cycle Cadet (Comer K80)	Manufacturers Cup
Sprint	2-cycle X30 TaG	Gold Cup
Sprint	4-cycle Animal	Gold Cup
Sprint	4-cycle Box Stock (Clone)	Gold Cup
Laydown-enduro	2-cycle	Road Racing
Sprint-enduro	2-cycle Yamaha, Piston Port	Road Racing
Sprint-enduro	4-cycle Animal	Road Racing
Sprint-enduro	4-cycle Box Stock (Clone)	Road Racing
Sprint-enduro	TaG	Road Racing
Shifter kart	125cc (2-cycle)	Road Racing
Super Kart	125cc, 250cc (2-cycle)	Road Racing