We have covered inside prep on a basic level in two previous articles that defined what it is, the differences in the two offered and some basic definitions on how they coordinate with the tires. We will outline below more specifics that will cover the basics of installation to details on how to maximize each to their potential.
Installation:
Proper installation is key to getting the most out of inside prep and it slightly more than just paying in some prep and letting them roll, here are some tips that the pros use:
Make sure all the work that you want done has been performed to the tire sub as cutting or surfacing and preliminary sizing. The reason we don't finalize sizing is it will change after the tire is completed rolling but we don't want to have to put any heavy heart cycles on it if we don't have to.
-Start by measuring the prep in device that either measures in cc's or ml's and measure out the appropriate amount.
-Make sure you're roller is level and turned on. You do not need a hot box rot roll tires prior to contrary belief heat can cause more damage to inside rolling a tire for the first hour then cold rolling as it can evaporate the solvents in the inside causing the tire to not react the same.
-Take and remove the valve core, and use a normal piece of 1/4" fuel line and insert over the tire valve assembly and compress the tire and hold until the other end of the fuel line is submerged in the prep and let the tire re-inflate. This will create suction and pull the prep inside the tire, as soon as all the prep has been suctioned in the tire, reinsert the valve core and inflate to no more than 3lb.
-Make sure the tire will not fall and become wedged in between the rollers and allow to roll for 24-36 hours. If you choose to use heat in aiding the prep to pull through the tire quicker during the cooler months of the year, it does not need to be set any higher than 100 deg. and allow the tires to roll at least 2 hours prior to turning the heat on to make sure that the liquid is absorb in the tire.
Re-rolling:
At some point in time you will want to re-roll a tire and there are various reasons why and things that should be kept in mind.
Always take and lightly warm one half of the tire up while leaving the other half at the ambient temperature and check to see what the durometer reading is for both sides. What this will tell you how that tire would react on the race track when under normal operating conditions and the tires are brought up to temp.
Age, type of inside used, number of heat cycles on the tire, outside weekly maintenance, general temperature range - all of these play factors in how a tire toughens up and determines whether or not a tire needs to be re-rolled.
A good rule of thumb when re-rolling is to use between 30 and 50cc and do so roughly no later than 10 days prior to them being ran. This will give you an opportunity to see a 10 day weather forecast as well as allowing the surface of the tire to firm back up while still having the prep active and ready to pull through when heat is applied.
The only instance where all of the above is voided is when its advantageous to roll the morning of the event. We see this may times being done when there is longer class being ran such as 50 or 100 laps and there will a defined stopping point for the tires to cool down and a need for them to re-fire. Rolling the morning of will allow the prep to only pull through half of the tire but will allow that portion of the rubber once its wore down that far to utilize the inside and have the tire stay more consistent durometer wise but not make the tire overly tender on the surface as if the tire was re-rolled with the normal allotted cure time to pull completely through the tire.
Use the same installation instructions for the initial rolling when re-rolling as well.