The theory with the 58 ring is apparently that it gives better chainline and smaller mechanical losses from the drivetrain. 58 x 12 being more efficient than 53 x 11. Roche was also riding a 58.
@Regal started
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The theory with the 58 ring is apparently that it gives better chainline and smaller mechanical losses from the drivetrain. 58 x 12 being more efficient than 53 x 11. Roche was also riding a 58.