Really nice pneumatic trail article in the last BQ talks about these effects as tires get wider, on pavement and off. The diagrams are great clarifiers too.
Andy Cheatham Pittsburgh On Tuesday, June 15, 2021 at 11:34:28 AM UTC-4 Patrick Moore wrote: > IME, this sort of self-steering and "wallow" at lower pressures is one > disadvantage of tires over a certain (say 35 mm? 38mm?) width on pavement; > dirt is another matter entirely because the tire does not "grab" the > surface in the same way, and a reason that one might well lose some of the > cushioning effect of fatter tires on pavement. > > I certainly experience this with 61s and even with 41s: keep them low > enough to benefit fully from the cushioning effect (+/- 20 psi for 60s, at > any rate, no more than 25 and ~35 for the 42s -- I'm 170) and they grab and > squirm and wallow in corners. My 2020 Matthews, with Naches Passes, does > not handle as crisply with 28 mm Elk Passes (~50 psi; 45 if I don't have to > worry about large expansion cracks) even at 45 psi, and certainly not at 35 > psi which is where the cushioning effect is greatest. > > You pays your money and you takes your choice. > > So, fatter is not entirely a free lunch. > > On Sat, Jun 12, 2021 at 10:29 AM Addison Quarles <bicycler...@gmail.com> > wrote: > >> What kind of noise are the tires making? Like a rubber skooching on a >> slick floor sound? >> The closest to the Antelope Hill that I've ridden is the Switchback Hill, >> which is 650b x 48mm. I've had them on three bikes over the years and would >> regularly pump them up to around 45-50psi once a month and not top off for >> another month so by the time I remembered to reinflate they would be down >> to around 20psi. This was in part due to negligence, but was also sort of a >> running experiment to see how the bike handled at different tire pressures. >> I didn't keep very good notes during this highly scientific study, but I do >> remember that by the 3 week mark the bike would dive into turns in a real >> scary way, perhaps something like you're experiencing with the self-steer. >> At higher pressures I never felt any handling anomalies, but maybe that's >> because I tended towards higher pressures. >> Have you considered bumping up to 50-55 psi? I imagine what you're >> feeling is that big ol' tire flopping over onto its side, bumping the >> steering one way or the other. My last Switchback Hill bike had 55mm rims >> and the think tracked like a freight train with no tire flop at all. >> Best of luck! >> On Saturday, June 12, 2021 at 7:48:55 AM UTC-7 Chris L wrote: >> >>> I just put a set of 55mm Antelope Hill tires on a set of Dyad rims and >>> installed them on my Hunqapillar. >>> >>> The tires, at slower speeds, have a TON of self-steer and in anything >>> other than a straight line, they are LOUD. >>> >>> Riding on a 3' wide sidewalk, just slightly turning the handlebar >>> results in the very loud sound of the tires. Is this something that >>> decreases as the tires get broken in? I assume it's one of the tread >>> patterns that may be more "grippy" to help in turns. >>> >>> The self steering is awful. I'm talking worse than a 1984 mountain bike >>> with Repack geometry. >>> >>> I started the tires at 40-45 psi, which as a 380 lb rider, is where I >>> generally run tires this size. During the ride, I lowered the pressure on >>> the front a little, but didn't notice any appreciable difference. >>> >>> I've run 38mm tires and two sets of 50mm + tires on the Hunq and never >>> experienced self steering at any level. >>> >>> >>> -- >> 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. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/rbw-owners-bunch/fcd10eef-d456-4b27-879c-b290461c1119n%40googlegroups.com >> >> <https://groups.google.com/d/msgid/rbw-owners-bunch/fcd10eef-d456-4b27-879c-b290461c1119n%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > > > -- > > ----------------------------------------------------------------------- > Patrick Moore > Alburquerque, Nuevo Mexico, Etats Unis d'Amerique, Orbis Terrarum > > -- 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 view this discussion on the web visit https://groups.google.com/d/msgid/rbw-owners-bunch/577c2607-d2d2-4f67-ba22-f5220d5748b9n%40googlegroups.com.
