Why camber cut tires?

    This cutting technique is to add camber to the tire and increase the amount of tread coming in contact with the track surface during cornering. This is done by shaving rubber off the
    face of the tire at a specific angle, thus increasing camber angle and reducing overall tread height. Importantly, camber cutting tires also reduce tread flex during cornering, which
    improves tire stability (track contact) and improves the grip of the tire on an asphalt surface. One additional benefit of cutting tires is that it reduces tread chipping or tearing, which is
    very common on uncut Legends and Dwarf car tires.  Finally, camber cut tires that are aggressively cut accelerate quicker out of the corner because they have less rotating mass,
    which is easier to accelerate.  On asphalt, newer camber cut tires are always faster than old, non cambered cut tires.    

Primary reasons to camber cut treaded tires

        1.  To reduce tread block squirm
        2.  To minimize tire tearing, chipping or chucking of outside edge
        3.  To increase contact patch during cornering    
        4.  To reduce rotating mass

At the Shop

    Tires can be cut to your specifications. Tell Mike, Roger or Chris what you want!) New tires from the
     factory come with an established tire tread depth of 10/32. Tires that have a depth of 2/32 have “hit the
     wear bar” indicator and are now considered to be illegal (by Legends rules).

 Leary Racing tire cutting provider offers three, cambered depth    cuts

       Entry-level - Lowest depth of 5/32-6/32 – This is a “non-aggressive” camber cut tire with an
             average tire life of 10-12 races. (Requires a significant  break-in session)
       Semi-pro cut - Lowest depth of 4/32 to 5/32 – This is an “aggressive” camber cut tire with an
            average tire life of 5-7 races -  Rated as “fast”.
       Pro cut  - Lowest depth of 3/32 to 4/32– This is camber cut tire which is typical used by top drivers
            and for a national event with an average tire life of only 3-4 races -  Rated as “very fast”.
       Special - This could be a tire very specific to your car or driving style.
       

Adjustments to cars with camber cut tires

    To optimize the use of camber cut tires, small adjusts to tire pressures; cross weight; camber angle and toe-out may need to be made. Use a needle type parameter (not an infrared
    surface parameter) to record tire temps. The objective is to get the (front) tires edge (closet to the inside of the race track) 5-7 degrees hotter than the outside edge of the tire. 

Pros of pre-mounting tires prior to cutting

    It is always the best practice to camber cut tires on the rims they will be raced on. Rims must be straight and in good condition before mounting tires and shaving. Once a tire is cut on
    a rim, you want to try to keep it mounted on the same rim for the duration of the tires life. If a rim is damaged and needs to be replaced, it is recommended that the tire be cut again
    to “true it” after mounting the tire on the new rim. Most tire cutters have a set of rims they can use for mounting/cutting purposes, but it is always best to use the rims that you will
    be racing on.

Tire circumferences and Stagger

    Since 2003, BF Goodrich has standardized tires diameters extremely well. This standardization, however, makes it very difficult to establish much rear tire stagger (which helps to get
    the car to turn left.)  Tire cutting providers do an excellent job at “matching” tires to gain small differences in diameter and small amounts of stagger, typically only 1/8 to ½  inch
    differences from left to right.
   
    NOTE: Let your tire cutter know how much stagger you want cut into the left side tires.(Tell Mike, Roger or Chris what you want!)

Proper break-in procedure – heat cycles

    NOTE: Prior to break-in, take a sharp razor (or snips) and cut off any of the little “nubs” left on the circumference of the tire. This will greatly reduce break-in time! Hence, a tire break-in period is essential. The more tread that is on a new Legends tire, the more heat cycles are required to break in a tire.
   
    The following break-in guidelines are based on the lowest tread depth measurement of a new tire: *

   Lowest depth of 5/32-6/32 – Typically 2 to 3 – 10 lap sessions at 60-80% throttle application with a full cool down time (tire cool to the touch) followed by another 10 lap
           session at 80-90% throttle application with a full cool down time followed by a short session under racing speeds. 
   Lowest depth of 4/32 – Typically 1 to 2 – 10 lap sessions at 60-80% throttle application with a full cool down time (tire cool to the touch) followed by a 7-10+ lap session at
           80-90% throttle application with a full cool down time (tire cool to the touch).  .
   Lowest depth of 3/32 – Typically 1 to 2  – 10 lap sessions at 80-90% throttle application with a full cool down time (tire cool to the touch).

    NOTE: Break-in periods can vary greatly depending on the track surface and driver style.

Durometer (hardness) readings

    Good tire cutters will perform a durometer (hardness) test on each tire they cut. On average, new tire will have a durometer reading of 57-58 (at 70 degrees.) Tires will harden as they
    go through heat cycles, increasing the durometer reading. Performance of a tire decreases significantly after a slight point increase in the durometer reading: e.g.  (58 to 62). After a 4
    point durometer increase, tire performance is greatly reduced.

Cutting procedure

    It takes approximately 4-4 1/2 hours to properly mount and cut camber into 4 new Legends  or Dwarf car tires and dismount tires. Right side tires require a different cambered angle cut
    than left side tires. Typically, both right side and left side tires require 12-14 passes of the (high speed) razor sharp, cutting blade. The greatest amount of cutting time is spent
    working on the large, rigid outboard shoulder block (outside edge of the right side tires), which enhances stability and traction for better cornering. Equally important to acceleration
    and braking is the center of the tire (referred to as the longitudinally linked tread block). To optimize the center section, it should be cut down significantly – no tread marks showing is
    the fastest tire.

    NOTE: Prior to break-in, take a sharp razor (or snips) and cut off any of the little “nubs” left on the circumference of the tire. This will greatly reduce break-in time!

Technical questions and contact information

    If you have any technical questions regarding the camber cutting process, you are always welcome to contact “Camber Cutters”™
    Gary Cagle, Ph.D.
    cell: 231-8983 or
    home: 970-223-5460 (leave a detailed message if he does not answer).
    email: cambercuttiresbycagle@gmail.com