Saturday, January 24, 2015

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


Sunday, January 4, 2015

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.