47 x 17 = 74.6 GI. A lovely number.
47x17 was my first guess but than I thought you might be putting something easier on your all-conquering Robin Mather tourcross bike. Damn.
@StandardPractice started
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47x17 was my first guess but than I thought you might be putting something easier on your all-conquering Robin Mather tourcross bike. Damn.