Metal fenders have a rolled lip about 4 mm wide, so that uses 8 mm of real estate. If you have 5 mm of clearance on each side that gets you to 18mm. So a 32 mm tire will want a 50 mm tire or more. You can cheat on that number a bit but you run more risk of both rubbing and trapping debris.
Plastic fenders don't have the lip and don't curl around the tire as much, so you can get away with a much smaller fender, but 1.5 mm is pretty tight, even if the fender doesn't cover to the widest point of the tire. I run 45 mm fenders with 29 mm tires on the Ram and 55 mm fenders with 38 mm tires on both our tandem & Saluki. Jan's 20 mm recommendation makes a lot of sense, if your frame & brakes will support it. Michael On Sunday, December 13, 2015 at 6:14:03 PM UTC-5, ted wrote: > > Jan Heine has written that they "... recommend 20 mm between tire and > fender for safety." > In the Roadeo write up RBW says you can put fenders over a 33.33mm tire > and without fenders can fit a 35mm tire. > That's only a 1.6 mm diff in size. I see lots of photos showing tire > clearance that look like there is a lot less than 20 mm there. > Most photos of fendered bikes I see don't look like they have that large a > gap either. > Do most folks really leave 20 mm (over 3/4 inch) between tire and fender? > Do most folks measure the clearance from the inner fender surface or from > the largest protrusion in there (e.g. mounting bolt for a light)? > -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at https://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/d/optout.
