Many tyres are scrapped due to bead damage that is often avoidable and/ or repairable. So, how can we prevent a bead injury from occurring? What options are there for repair? Is the process different for bias and radial tyres?
Our guide takes a look at these key questions and shares how Monaflex truck and OTR bead repair systems can help.
The bead area of a tyre can be subject to damage sustained by:
Water Hammer Effect – a pressure surge or wave caused when a fluid in motion, usually a liquid but sometimes also a gas, is forced to stop or change direction suddenly; a momentum change.
Only damage to the bead rubber which exposes the bead bundle or body cords can be repaired. Injuries generally caused by incorrect handling, mounting or dismounting which impede sealing of the tyre or maintaining recommended inflation pressures.
If any part of the bead bundle, body cords or structural components of the tyre are damaged no attempt should be made to repair the tyre, it should be scrapped.
For repairable bead damage of all types, Monaflex offers a solution for use in both Truck and mid range/ XL OTR tyres.
The quick to assemble system uses a single heat pad wrapped around the area to provide uniform temperature whilst the flexible, inflatable airbags ensure perfect conformity to the bead.
Take a look at our systems:
MBRS – mid range OTR bead system for 18.00R25 to 45/65R45
XL BRS – XL OTR bead system for 40.00R57 and 59/85R63
BRS – truck bead system for 8.25 to 12.00R24
Monaflex OTR and Truck bead repair systems have traditionally been used for radial tyres only but can also be used for repairs to the bead of Bias tyres.
By filling the repair using a chemical cure A & B compound, the Monaflex system can be used to exert pressure on the repair and ensure the strongest possible cure. If you’d like to learn more about this methodology, please just get in touch.
The bead area of any tyre is made up of a bead bundle, a bead apex filler and a bead chafer. Each has a separate function, yet each piece must rely on the other to function the way tyre design engineers intended. The main function of bead wire is to hold the tyre on the rim and to resist the action of the inflated pressure. Bead wire is the crucial link through which the vehicle load is transferred from rim to the tyre.
The bead is composed of:
Typically, a bead bundle comprises of numerous large monofilament steel cords. The cord is coated with rubber and then wound into a loop. The loop size is based on the wheel diameter. The resulting bundle is then wrapped with a ribbon of rubber-coated ribbon material. The cords within the bead help the tyre retain its shape and maintain the tyre’s seal as it is subject to distortion and vibration.
At the apex bead filler, a rubber compound, is incorporated within the bead configuration and extends into the sidewall area. The rubber compound used on the outside bead area is usually hard, and durable so as to withstand the rigours of mounting the tyre to the wheel and cut resistance when in service.
Another function of the bead apex filler is to create a smooth contour for the body plies around the bead wire in the lower sidewall area.
The remaining component in the bead area is the bead chafer, or chafer strip. Its function is to protect the bead area from rim chafing, mounting/dismounting damage and to prevent the tyre from rotating on the rim. Chafer strips are made of a hard, durable compound rugged enough to withstand the forces working against it.
Please note: any advice given by MVS Ltd. Does not replace instructions supplied by manufacturers of your components. Always refer to your material supplier or manufacturer for specific advice and note that it is your responsibility to consult, and adhere to, all relevant guidelines and legislation – please refer to our tyre repair safety considerations and disclaimer.