Compatibility with Schwinn S7 Rims. Schwinn S7 Rim Standard. TheHF-120A (20 x 1.75) andIA-1521 (20 x 2.125) tires are designed exclusively forISO 406 rims. Attempting to mount these tires on Schwinn S7 rims would result in improper fitting, creating a safety hazard and rendering the tires unusable.
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