WHY MICHELIN REGROOVING?
Benefits Of Regrooving
Michelin truck and bus tyres are engineered for multi-life, and are therefore regroovable and retreadable!
- Regrooving is carried out at a time when the original tread depth has 3 to 4mm remaining and the tyre is normally removed. Regrooving restores tread depth thus providing up to 25% more kilometres.
- Regrooving significantly renews the grip of the tyre through the regeneration of the groove up to 4mm beyond the original bottom of the groove.
- Regrooving is carried out in the phase when the tyre has the lowest rolling resistance due to higher rigidity of the shallow tread pattern, and low rolling resistance means increased fuel efficiency.
- By adding only 5% additional rubber volume when the tyre is new, a Michelin Regroovable tyre will add up to 25% more kilometers which creates a 6% reduction in raw materials when compared to non-regroovable tyres.
A regrooved tyre can restore up to 4mm of tread depth. That can be as much as 25% of the original tread depth.
Regrooving does not affect the structural integrity of the casing. A tyre with 4mm remaining tread, once regrooved, is refitted with 7-8mm remaining tread which offers increased skid depth and enhanced safety. Regrooving can improve lateral grip and drive by 10%!
Tyres become more fuel efficient at approximately the last 30% of tyre life because their rolling resistance goes down during this period. Rolling resistance is a measure of force required to get the truck moving and keep it rolling. The difference in rolling resistance between new and the last 1/3 of tyre life is about 25%. This equates to 4-6% improvement in fuel economy!
Now, combine Fact 1 and Fact 2 together and you extend the time that the tyre operates in this optimum rolling resistance period. So instead of achieving the best fuel economy for only 30% of the tyre life, you can extend it to 40% of the tyre life just by REGROOVING!
A tyre’s grip is determined by many factors such as rubber compounds used, the tread pattern, foot print size, an the ability to evacuate water from under the contact patch. As the tyre wears down, the ability to evacuate water also goes down. By restoring the main rain grooves up to 4mm, you also restore the ability to channel the water out and away from the footprint.
Regrooving can also restore some of the lateral grooves that get worn away towards the end of tyre life. This provides new biting edges thus regaining grip performance lost when a tyre wears down.
To improve the tyres impact on the environment, we need to reduce the amount of CO2 production. We know from studies that 5% of CO2 productions comes from the manufacture of new tyres in the form of raw materials, energy used for production and distribution. These studies also reveal that 93.5% of CO2 production comes during the trucks operational period in the form of fuel consumed.
Simply put, if we can make the tyre last longer and get better fuel economy, we can reduce the CO2 produced! REGROOVING your tyres accomplishes both of these goals.
- Up to 25% improvement in tyre life.
- 4-6% improvement in fuel efficiency when compared to the start of tyre life.
- Extends the operational time of the tyres peak fuel efficiency.
If you add the tread depth at the beginning of life, you increase the heat generation of the tyre. Heat is the main enemy of a tyre and creates a negative impact on casing fatigue and fuel efficiency. The wear rate is also affected because taller tyres produce more slippage as the tread exits the contact patch causing a faster wear rate.
By engineering the tyre with the ability to REGROOVE, you can gain the advantages of adding up to 4mm of tread without any of the adverse effects mentioned above.
Many Michelin tyres have a regrooving well in the centre of the tread wear indicators as a guide for high-quality regrooving. Some tyres do not have these indicators but are still fully designed for and ready to be regrooved. Just follow the steps detailed below to ensure the proper depth is obtained.
Michelin new tyre design regroove capability to extend life beyond the original tread depth.
Inspect the tyre thoroughly while checking for any exposed steel cords or casing damage which would otherwise prevent the tyre from operating safely. Remove any stones trapped in the tread before regrooving.
Verify the remaining tread depth is between 2mm and 4mm by checking several locations around the tyre. If any area of the tyre has no measurable tread depth remaining, the tyre should not be regrooved.
Confirm the recommended regroove pattern, regroove depth and regroove tool blade shown in the following pages for the selected tyre.
Place the tyre in a regrooving stand or other location where it can be safely handled throughout the regrooving process.
Begin with the first groove by measuring the remaining tread depth in the most worn area. Add this remaining tread depth to the recommended regroove depth to establish the regroove tool setting. For example, if the first groove has 2mm of tread remaining and the recommended regroove depth is 3mm, set the regroove tool to a total depth of 5mm.
Regroove a small section of this first rib (10-15cm in length). Using a tread depth gauge, measure the resulting tread depth to verify the correct reading. In the example above this tread depth reading should be 5mm. If the reading is not correct, adjust the tool accordingly. Once the regrooved tread depth is correct, proceed with the remainder of the rib.
Repeat steps 5 and 6 for the remainder of the tyre.
Regrooving For Different Usage Conditions
Carry out the regrooving when there is still 2 to 4mm of tread.
This precaution makes it possible to:
- Reproduce the tread pattern easily.
- Adjust the regrooving depth so as to always keep at least 2 millimeters of compound between the bottom of the tread pattern and the crown layers.
If Regrooving is too deep it may:
Result in damage that could cause the premature destruction of the casing.
- Compromise the possibility of retreading.
- Allow metal layers of the crown to appear, which may reduce the life of the casing.
- Multiple holes and cuts or areas where the tread has been torn off.
- Exposed metal layers of the crown that can be seen through damage or cuts