Whether you get inch flats in my experience is almost, if not entirely, as much a matter of how you ride than what your pressure is. I rode 22 mm actual tires, quite supple -- these were the old Specialized 26 X "` Turbos, very nice except for width -- at 80/90 for years with rear loads up to 35 lb across rough pavement with no problems except breaking the occasional Revolution rear spoke (I fixed that by having the wheel rebuilt with 14/15s). I let my front tire pressure on 60 mm tires drop to as low as 12 psi and never came close to pinch flatting.
Two other observations: I've noticed what others have reported: stiffer, heavier tires can get by with lower pressures than supple, light ones, so that some of the advantage of a supple tire, at least 50+ mm wide ones, and when run off pavement, is lost because you have to pump them harder. I used to regularly run my 60 mm Big Apples at 16/19 (I'm 175): sure, these flopped a bit on pavement turns, but I never came close to pinch flatting. With my new Big Ones, at ~15 front, I thought I'd fall off the bike when I made my first pavement turn, so great was the flop, and I quickly increased pressure to that I used in the 1 cm narrower F Freds, 23 (25-6 rear) -- which makes them less cushiony on dirt than the Big Apples. (Note: I used tubes in the BAs; the BOs are tubeless, so the absence of tubes may increase the required minimum pressure slightly; I don't know.) But the Big Ones are worth it despite no added cushioning because they seem to roll almost as fast on pavement as good road tires; at any rate, they're faster than the already fast F Freds on pavement. And: as far as avoiding pressures that allow wheel flop in turns: I have concluded that there is no perfect all round pressure for, at least, (a) supple tires that are (b) fat and (c) ridden on pavement and on dirt: you will either have some front wheel flop, or your pressure will be less than ideal for soft dirt. But you won't get pinch flats if you are careful on any except perhaps the most bumpy terrain. All of the above for a given rim width. Wider or narrower rims affect performance, obviously, which leads to the last observation: wider rims for a given tire, at least for 50 and 60 mm wide tires of given suppleness, reduce the tire's cushioning effect at a given pressure. I noticed that, when I swapped 24 mm wide rims to 44 mm wide ones, the 60 mm Big Apples felt harsher at the same pressures. On Wed, Jan 17, 2018 at 8:03 AM, Surlyprof <jmcclu...@gmail.com> wrote: > Tom, > > I agree with Patrick. I ride Barlow ELs at about 40# which is close to > what he’s suggesting Keven Moran, when he was at Riv, suggested I lower the > pressure and showed me his bike to prove he ran them low. I tried it on an > old mountain bike that had too narrow rims for the tires and it was scary. > Felt like my tires were about to roll off the rims. With the BPs on > Synergy rims I have worked back down to a lower pressure despite my fears. > Of course it took a while to get there and I came to it accidentally out of > laziness more than anything else. I hadn’t ridden for several weeks and > didn’t bother to do a quick once over before heading out. I freaked out a > bit when I saw that my tires were expanding out at the bottoms. But, again > being lazy, I ignored it and continued my ride. Shortly after I was just > enjoying the ride and forgot about it. The ride was the smoothest I’d > experienced. I checked the tires when I got home and they were at 40 in > the front and 35 in the rear. Been hovering around 40 ever since and have > become much more confident on gravel. No flats, pinch or otherwise, in a > year and a half. > > John > > -- > 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. > -- Resumes, LinkedIn profiles, bios, and letters that get interviews. By-the-hour resume and LinkedIn coaching. Other professional writing services. http://www.resumespecialties.com/ www.linkedin.com/in/patrickmooreresumespec/ Patrick Moore Alburquerque, New Mexico, Etats Unis d'Amerique ************************************************************************** ************** *Auditis an me ludit amabilis insania?* -- 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.
