> On Oct 25, 2013, at 8:51 AM, Jan Heine <hein...@earthlink.net> wrote: > > The problem lies with the rim, not the tire. All tires will fit poorly on the > Synergies, whether 650B or 700C. You can make it work – I use the Synergies > on my own bike – but the tire doesn't seat automatically as it should. If you > don't have problems, then you are mostly fine. There still is a minor safety > issue if you have a sudden blowout, the tire might come off the rim more > easily than with a well-designed rim. > > If you cannot get the tire to seat well, and it runs wobbly no matter what > you do, then it's the rim, not the tire's fault. Generally speaking, seating > a tire with stiff sidewalls (and a wire bead) is easier, because the tire > wants to assume its round shape. A supple tire with Kevlar bead can be harder > to seat if the rim doesn't support it as it should.
To piggy back on this, bead seating is a issue especially in terrain where you'll be doing prolonged braking and heating the rims. From discussions I have read about this with bike-interested engineers, the theory is not that the heat raises the pressure in the tire causing the blowout but that the heat causes the rubber in contact with the rim to become a bit slippery. This allows the bead to squirm over the hook and escape over the edge of the rim. A lot of heat can be generated by braking- hot enough to boil a drop of water with enough braking- and it tends to be generated right about where the tire bead is in contact with the bead seat. The only mountain riding I have done was in the Alps in 2002. There the roads are open enough that you only have to brake sporadically, but even then the rims got quite warm to the touch on some of the more snaky descents or where there was car traffic and one had to slow down to their speed. Most drivers would pull over a bit to let bikes pass them, understanding that in many cases the bikes would be faster down the curvy bits. -- 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/groups/opt_out.
