Re: [CR] Panaracer Pasella 27x 1 1/4 sidewall blow-outs @ 50psi. Advice Sought

(Example: History)

Date: Sun, 21 Mar 2010 19:46:59 -0600
To: Guy Lesser <guyless@thing.net>,classicrendezvous@bikelist.org
From: "Mark Stonich" <mark@bikesmithdesign.com>
In-Reply-To: <BA8B5B78-37D1-400B-A328-46CECE927FEC@thing.net>
References:
Subject: Re: [CR] Panaracer Pasella 27x 1 1/4 sidewall blow-outs @ 50psi. Advice Sought


Guy, Did the tube blow out right through the sidewall of the tire or did the bead slip off the new rim? If it's the later I suspect the rim is a bit undersized. Many of us have had great luck with Pasellas and other PanaRacer tires. Sometimes rims are undersized, sometimes oversized. Same for tires. You have no history of other tires staying on the new rims. And the odds of getting two oversized tires in a row, clearly not from the same batch, from a manufacturer with PanaRacer's reputation are pretty slim. Not exactly zero but pretty close

OTOH If you really did have sidewall blowouts at 50 PSI I'm amazed. Jane and I and many others have plenty of miles on these tires at higher pressures.

At 3/21/2010 05:54 PM -0400, Guy Lesser wrote:
>Hi All,
>Apologies for a long post.
>
>I continue to regard myself as a very recent albeit passionate
>convert to vintage steel, and thus do try to be philosophical about
>learning from mistakes, being forthright about how very little I
>really know, and in readily seeking advice from so many of you who
>have long memories and vast experience.
>
>I realize the topic of finding great period appropriate 27" tires/
>tyres for 27" wheels is as old as the list, and a source of some
>longstanding frustration, but since it hasn't inspired much comment
>the past couple of years (at least in my own search of the archives),
>I thought I'd raise it again.
>
>In my own case, I am trying to make a pair of newly-built wheels work
>better than what I had.
>
>The new wheels are a pair of 27" vintage Mavic rims (just a hair over
>20mm wide) very similar to Super Champion M58s (or thier various more
>modern successors such as the new Grand Bois 650Bs)-- which is to say
>straight walls, small bead but not hooked. (These were laced to
>vintage Campagnolo 36h Gran Sport hubs by a very able NYC list
>member). My previous wheels were a pair of vintage Ambrosio 36h rims
>that were never particularly true, slightly skittish and had a
>freewheel that was a bit narrower than what I really liked (and
>rightly or wrongly, I assumed that the tires were likely a factor in
>what I didn't particularly like).
>
>In terms of tires, I initially considered (blissfully unaware of the
>problem of sidewall blowouts especially with Kevlar bead models),
>since all are readily available:
>(1) Conti (Ultra Sports and Gator Skins), (2) Schwalbe (Marathons and
>HS 159s), (3) Michelin World Tours, (4) Victoria (Rubino Techs and
>Zaffiro) and (5) Kenda K35s.
>
>I foolishly started with a pair of Panaracer Pasella TourGuards
>mostly because they looked right, and since Panaracer manufactures so
>many of the popular KOF tires like Rivendell's rolly polly and ruffy
>tuffy, I hoped that they might be a bit more tuned in than other
>manufacturers to the more obvious implications of a 27" sized tire--
>such as the likelihood many users would be using them on older styles
>of rims.
>
>The TourGuards lasted about 48 hours at something around 50psi before
>I even more foolishly tried to follow Sheldon Brown's time tested
>70psi recommendation (which had by the way, proved a very happy
>pressure for the Conti Ultra Sports I'd had on the Ambrosios). A
>gunshot loud pop surprised me about half an hour later. I
>subsequently discovered a vast well of web bike lore warning of the
>dangers of trying to mount virtually any kelvar tire on older
>straight sided rims, and accordingly, I swapped out the Pasella
>TourGuards for a pair of their less expensive wire bead Pasellas, and
>ran these for a week at 40-45psi, worrying about pinch flats and the
>rest (though I did discover a minority taste among a small group of
>enthusiasts who favored running tires at the very lowest practicable
>pressure, even down to 25psi).
>
>So, the next question was what WAS the optimum pressure for wire
>Pasellas? And closely related, what was an absolutely safe maximum?
>55psi seemed a reasonable guess given my weight (around 150lbs and my
>typical load of >50lbs). This time, it took roughly 20 minutes for
>the new wire bead Pasella to blow.
>
>So, here we are.
>
>For me, at least, all Panaracer is wholly and permanently off my list
>forever. And I'm now at what next? What I'd like ideally is (1)
>something safe and reliable that won't hurl me sideways into a
>speeding taxicab in rush hour traffic, (2) something that actually is
>or looks appropriate to a late 1950s --early 60s Hetchins tourer, (3)
>something that performs well-- with a nice ride at the top of my
>criteria-- but which is also ideally fairly nimble, and fairly
>puncture resistant on gritty urban streets.
>
>I absolutely hate the looks of Gatorskins (in this context), and have
>trouble mustering up much enthusiasm for Marathons (though I run a
>pair very happily on a non-KOF bike, they are about as far from
>nimble as you can get, and look very German and post-1990s at least
>to me). I'll settle, if I have to, for a new pair of Ultra Sports--
>but my hope was to find something noticeably better. And to this end
>I am more than happy to hunt or splurge on something NOS if it
>exists. In this regard, I've ordered a pair of NOS gumwall Wolbers of
>unknown vintage and model (from a list or former list member) with
>the curiously hedged marking 27" x1 1/4" x 1 1/8", and will give
>these a go next.
>
>Meanwhile, was there EVER a truly great clincher-- and if so, what
>was it and who made it? Or is there anything in the pipeline in the
>way of 27" combining comfort AND speed that might compare with the
>wealth of new 650B tires (like say the Hetres or the new Kirk Pacentis)?
>
>And if Sheldon Brown's oft quoted 70psi is wrong-- at least in some
>instances, what is right? Especially with modern tires like the
>Pasellas which have a recommendation of 95psi on their sidewalls.
>
>Any or all advice gratefully appreciated. And of course if you have
>something rare and miraculous you're willing to part with, do send me
>an email.
>
>Guy Lesser
>Brooklyn, NY
>
>_______________________________________________

Mark Stonich;
     BikeSmith Design & Fabrication
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