History of “On The Wheel” Repairs
When tubeless tires first appeared in the market place there two types of outside/ “on the wheel repairs” repairs. The rubber plug and the string type repair. The rubber plug consisted of tab of preset cured rubber, when dipped in rubber cement made a temporary repair. The product was difficult to insert into small punctures and ineffective in repairing irregular punctures (glass cuts ect.). When the rubber cement dried and cracked under road heat and pressure the repairs often leaked. With the advent of steel belted radial tires the insertion of the rubber plug became almost impossible as the plug often broke upon insertion.
String type repair consisted of a thin usually cotton string, that was immersed in a non-vulcanizing rubber solution. Since it was impossible to saturate anything larger than a thin cord the single strand was put into the injury and twisted to form a multi-layers and pulled back allowing sufficient layers of yarn to repair the puncture. The un-vulcanized rubber solution made a temporary repair as road heat and normal tire pressure caused the sealant to ooze or ”wick” from the yarn leaving it uncoated.
Both types were temporary and did not make an effective seal.
In the late 1960’s A.W.Niconchuk a rubber chemist and founder of North Shore Labs Corp Peabody Ma. undertook extensive research and development to produce the first permanent “on the wheel” repair. The patented process consisted of coating selected synthetic yarns with a proprietary vulcanizable rubber cement then twisting the coated parallel yarns into a repair unit larger enough to repair up to ¼” puncture. The repair unit was subjected to heat for partial vulcanizing but remained soft pliable and tacky.
This new product Safety Seal made a safe effective repair. Niconchuk further developed a special split eye insertion needle to install the repair. The product was an instant success. Safety Seal has sold over a billion repairs worldwide and this type of repair has been imitated but never completely copied by numerous other manufactures.