I think Eric's points are very well worth considering. The tighter tolerances leave little room for error. If you load your bike in the back of the car, there is a good chance that the fender will be knocked out of your perfect line. If you are prepared to live with that tight tolerance then maybe tighter is better. I will admit that my only experience with sudden failure is having an acorn penetrate my wife's rear fender, which was open to accommodate horizontal drop outs. michael
On Friday, October 17, 2014 10:43:29 AM UTC-4, Eric Norris wrote: > > I’ve read Jan’s article and various emails and comments about fender > clearance, but I haven’t seen anyone address the possibility that tight > fender clearances improve safety by helping to *exclude* objects from being > caught between the fender and tire. If I have 1cm of clearance (about a > half and inch), then objects (twigs, branches, etc.) that are that size can > easily slip between the wheel and fender. Wouldn’t a tighter clearance—say, > 1/4 inch—keep a half-inch-size twig/branch out? Personally, I would much > rather deal with a 1/4-inch twig than one that is twice the size and much > harder to break and therefore much more likely to cause a fender > catastrophe. > > As Jan mentions in his BQ article, most of the classic randonneur machines > had very tight fender clearances. Perhaps this is one reason? > > Am I off base here? > > —Eric N > > > On Oct 17, 2014, at 5:12 AM, Michael Hechmer <mhec...@gmail.com > <javascript:>> wrote: > > The rule of thumb for metal fenders is tire size plus 18 mm as a minimum. > This allows 4 mm for each rolled edge and 10 mm of clearance. If you can > go somewhat bigger than that, you should. The added space gives you the > option of bigger tires in the future and reduces the chance of something > jamming between the tire & fender. 32-42 is pretty wide range,so I would > suggest 60 mm fenders if they will fit. Honjos are elegant. VO fenders > are also nice. Bertoud fenders are the sturdiest. Properly installed they > should last a long time, so a few dollars more or less is probably not the > best criterium. > > Michael > > On Monday, October 13, 2014 11:46:09 PM UTC-4, lungimsam wrote: >> >> 1. How much clearance above tread, all around tire? >> 2. How much clearance from sides of tire (where the rolled edges envelope >> sides of tire)? >> 3. Should I just get the widest fender that will fit on the bike? I am >> hoping to settle on 32-42mm Compass/GB tires for my Bleriot. I have Hetres >> on it now, but no fenders yet. >> >> I will have to re-check the latest BQ issue for the fender safety >> article. I think it said minimum 1.7cm vertical clearance all around tread? >> > > -- > 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-bun...@googlegroups.com <javascript:>. > To post to this group, send email to rbw-owne...@googlegroups.com > <javascript:>. > Visit this group at http://groups.google.com/group/rbw-owners-bunch. > For more options, visit https://groups.google.com/d/optout. > > > -- 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 http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/d/optout.
