[TR] Tire/Tube Q.

nwolf at u.washington.edu nwolf at u.washington.edu
Tue Jan 13 12:30:31 MST 2009


Hi Randall

>Date: Mon, 12 Jan 2009 16:58:47 -0800
>From: "Randall" <tr3driver at ca.rr.com>
>
[snip]
>The safety beads primarily come into play when the tire has already lost its
>air and you are still driving on the flat.  Losing air in a corner with
>normal inflation (over 20 psi) is an urban myth IMO.
[snip]
>Randall

   I can give you a counter-example involving a '65 VW Bug hitting a small pothole in the middle of a hard left-hand turn.  Big "POP!" and the right rear tire was loose on its rim.  Contributing factors were the rear engine, full back seat, and spirited driving (it was high school, OK?).  In any case, it IS possible to unseat a fully inflated tubeless tire on a non-safety rim, but it's not easy and it's not going to happen under normal driving conditions.  (My TR4 has the American Racing 8-spokes with no safety bead and no tubes, and I haven't had any trouble.)

   As a side note, my Bug was a bone-stock swing-axle car and it's worth pointing out that the tire popped off long before the swing axle would have had a chance to tuck under.  Take THAT, Ralph Nader.  :)

   Back to the 165R15 or 165/80R15 problem, the major manufacturers have really given up on us.  This means we're stuck with low-volume producers whose products are generally not subect to consumer review (e.g. customer feedback on tirerack.com).  If you're not already consulting these reviews for other tire purchases, you really should, because there is HUGE variation in traction and performance between different tire models, even from the same reputable manufacturer.  I found this out the hard way.

   I wonder if it would help if a bunch of different classic car groups teamed up as a united front to lobby Michelin for a decent, modern 165R15?  This really was a very common tire for small import cars in the 50's and 60's:

VW Beetle, Squareback, Karmann Ghia, etc
Volvo 444, 122S (Amazon), 140, etc
Saab 95, 96, 99, etc
Triumph TR2-TR4A
Porsche 356, 914, possibly early 911/912
Alfa Romeo Giulia, Giulietta, GT, etc
MGA
...and many others.

   Hmm, I've personally owned six cars from that list, so maybe I'm biased.  ;)

-Nick Wolf
Seattle
'62-ish Triumph TR4 (165R15 Cooper Sportmaster GLT)
2000 VW New Beetle TDI (ridiculous tire size - 205/55R16)


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