Tire blow-off



A

Anthony DeLorenzo

Guest
I recently purchased a new pair of Panaracer Paselas, 700x35C with
kevlar bead. With less than 20 km riding, I had the rear tire blow off
the rim (Araya touring rim) while the bike was parked. I replaced the
tube, but the next day it blew off again, thankfully while parked.

I thought it might be a problem with a too-small rim, but I tried the
tire on a Velocity Dyad and it blew off while I was airing it up, I
had reached about 75% of recommended PSI.

The other tire in the pair was fine mounted on a Sun Rhyno Lite and a
Sun CR18.

I am thinking I might have gotten a bad tire. Is there some problem I
should look for, like a crack in the bead or something? If I can find
something wrong with it I'll try to return it.

Regards,
Anthony
 
On Aug 15, 10:19 am, Anthony DeLorenzo <[email protected]>
wrote:
> I recently purchased a new pair of Panaracer Paselas, 700x35C with
> kevlar bead. With less than 20 km riding, I had the rear tire blow off
> the rim (Araya touring rim) while the bike was parked. I replaced the
> tube, but the next day it blew off again, thankfully while parked.
>
> I thought it might be a problem with a too-small rim, but I tried the
> tire on a Velocity Dyad and it blew off while I was airing it up, I
> had reached about 75% of recommended PSI.
>
> The other tire in the pair was fine mounted on a Sun Rhyno Lite and a
> Sun CR18.
>
> I am thinking I might have gotten a bad tire. Is there some problem I
> should look for, like a crack in the bead or something? If I can find
> something wrong with it I'll try to return it.
>
> Regards,
> Anthony


FWIW, I've met a Pasela with a similar issue, can't remember the size.
 
Anthony DeLorenzo wrote:
> I recently purchased a new pair of Panaracer Paselas, 700x35C with
> kevlar bead. With less than 20 km riding, I had the rear tire blow off
> the rim (Araya touring rim) while the bike was parked. I replaced the
> tube, but the next day it blew off again, thankfully while parked.
>
> I thought it might be a problem with a too-small rim, but I tried the
> tire on a Velocity Dyad and it blew off while I was airing it up, I
> had reached about 75% of recommended PSI.
>
> The other tire in the pair was fine mounted on a Sun Rhyno Lite and a
> Sun CR18.
>
> I am thinking I might have gotten a bad tire. Is there some problem I
> should look for, like a crack in the bead or something? If I can find
> something wrong with it I'll try to return it.


It's possible but only remotely. More likely an installation problem. Do
you spin the wheel at 1/2 pressure to ensure the molded lip just above
the brake track is even all around before fully inflating?
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
 
Anthony DeLorenzo wrote:
> I recently purchased a new pair of Panaracer Paselas, 700x35C with
> kevlar bead. With less than 20 km riding, I had the rear tire blow off
> the rim (Araya touring rim) while the bike was parked. I replaced the
> tube, but the next day it blew off again, thankfully while parked.


If it's a *really* old Araya, make sure the rim has a bead hook. In the
70's Araya made a really pretty rim (heavy, but pretty) with straight
sides. That would explain blowoffs. Such rims shouldn't be used with
folding tires.

> I thought it might be a problem with a too-small rim, but I tried the
> tire on a Velocity Dyad and it blew off while I was airing it up, I
> had reached about 75% of recommended PSI.


OK, Dyads *do* have a bead hook. Make sure you aren't pinching the tube
underneath the bead, and check for proper bead seating at about 10-20
psi before inflating to full pressure.

If these aren't the problem, could be a bad tire as you suggest.

Mark J.

> The other tire in the pair was fine mounted on a Sun Rhyno Lite and a
> Sun CR18.
>
> I am thinking I might have gotten a bad tire. Is there some problem I
> should look for, like a crack in the bead or something? If I can find
> something wrong with it I'll try to return it.
>
> Regards,
> Anthony
>
 
Anthony DeLorenzo wrote:
> I recently purchased a new pair of Panaracer Paselas, 700x35C with
> kevlar bead. With less than 20 km riding, I had the rear tire blow off
> the rim (Araya touring rim) while the bike was parked. I replaced the
> tube, but the next day it blew off again, thankfully while parked.
>
> I thought it might be a problem with a too-small rim, but I tried the
> tire on a Velocity Dyad and it blew off while I was airing it up, I
> had reached about 75% of recommended PSI.
>
> The other tire in the pair was fine mounted on a Sun Rhyno Lite and a
> Sun CR18.
>
> I am thinking I might have gotten a bad tire. Is there some problem I
> should look for, like a crack in the bead or something? If I can find
> something wrong with it I'll try to return it.
>
> Regards,
> Anthony
>


I had the same problem with exactly the same tire. On close inspection,
the tire was manufactured with a defect; the hook near the bead of the
tire that engages the hook in the rim was not concentric with the bead,
but drifted well away from it in one section on one side of the tire.
As a result, the tire could not be made to seat properly in the rim.

Dave Lehnen