Functional bikes. Not Porn not Anti

Source?

Here:

If you use these fenders with wider tires, you encroach on the clearance between tire and fender. We recommend 20 mm between tire and fender for safety. If you use a tire that is about 8 mm wider, you reduce that to 12 mm. The bike will be rideable, but it's less than optimal. I wouldn't ride a bike like that on gravel.

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