In every day street use, three-piece wheels will provide years of service and require no special maintenance other than standard tire care and valve core replacement at tire change intervals. If you use your wheels for competitions and racing, it is recommended that both 1-piece and 3-piece modular wheels undergo inspection at the end of each season. For monobloc wheels, a thorough cleaning and visual inspection for any signs of stress cracks or fatigue as well as runout checks would be sufficient. If the wheels have undergone any type of impact damage and remained intact, it is strongly recommended that they are x-ray tested or have their finish stripped and undergo a dye penetrant test. The former is the most preferred, but if your preparation for a new season involves refinishing the wheels, the latter may be more practical since the finish will be removed anyway.
Three piece modular wheels require the same periodic maintenance as described above for monobloc wheels. Additionally, since racing involves frequent tire mounting and dismounting, it is also advisable to disassemble, thoroughly inspect, clean, re-seal, and re-torque each wheel.
- Whenever you disassemble the wheels, it is also necessary that you replace the bolt and nut, and make sure that they are correctly torqued.
- Proper torque on an 8mm blind bolt is 15 ft/lbs, whereas through bolts with nuts are recommended at 28-30 ft/lbs.
- Clean the surfaces where the wheel and tire meet with a proper cleaner then apply a skim coat of silicone sealant to the two surfaces, reassemble the wheel, mount, and secure the bolts to the proper torque specifications.
- Replace the old valve stem with a new unit and install.
- At the drop center area of the wheel apply a thick layer of silicone sealant and allow it to set and harden for at least 24 hours before the wheel is mounted.
In the event you come across an issue where you’re losing air, below are some methods to further test where the leak is coming from.
- Inflate the tire to 40 psi, even if it is above the recommended tire pressure.
- Mix together soap and water then spray or pour it onto the wheel and tire.
- Take a tire crayon and highlight where the bubbles form on the tire/wheel.
- If the bubbles indicate a leak in the wheel or tire, you can reseal the wheel by using the maintenance procedure listed above.
The most popular cause for leaking wheels:
- Damage to silicone during tire servicing. Being that 3 piece wheels can be a challenge to mount tires on, tire techs must use a tire spoon (in some cases two) in able to manipulate the tire onto the wheel. In the process of handling the tire, the tire spoons come into contact with the barrel of the wheel and if done without extra care, the spoons can come in contact with the silicone causing the silicone to lose its retention and later leak.
- Use of liquid tire repair agent (fix-a-flat or other). In the unfortunate event of a flat tire, some will resort to a quick fix using a liquid tire repair. The harsh chemicals in these agents can cause two things that will later lead to leaks: 1. The silicone will be damaged with the harsh chemicals causing the wheels to later leak. 2. Some liquids are so harsh that they’ll eat the chrome from the barrels (if chromed) where the tire bead meets the barrel and cause air to escape.