First blowout

Quite scary. Near the bottom of a hill with c. 50 kg. of trailer and kids
behind me when the front tyre went with a bang. No further damage
thankfully. So now I need a recommendation for a good solid commuting tyre.
Weight is not an issue and although it's a cheap bike I'm quite happy to
splash out on decent reliable tyres. The rim is a Weinmann Zac 2000, size
700c. The old tyre is a WTB Allterrainassaurus size 32/30. The tyre only had
about 1000 miles use and the blowout happened at a point just above where
the tyre is seated in the rim. The hole runs lengthwise round the tyre for
about 2 cms. and there are signs of wear for about 5 cms. on either side of
the hole. So I'm wondering if maybe it was just a bad rim/tyre combination.
There is very little sign of wear elsewhere on the tyre. I'm fairly good
about checking brakes for rubbing etc. so I don't think that was the cause.
I've just noticed the rim is slightly out of true, maybe that contributed?
Anyway, a good commuting tyre please? I've used Conti TT and TT 2000 on my
tourer and found them to be complete *******s to get on and off its Mavic
rims. It now has Schwalbe Marathons which are showing sidewall cracks after
c. 3000 miles. However none of these blew out or indeed punctured over much
so if they're the panels recommendations then fine. Thanks for the help,
Tony R.

"tony R" wrote in message
...
Quite scary. Near the bottom of a hill with c. 50 kg. of trailer and kids
behind me when the front tyre went with a bang. No further damage
thankfully. So now I need a recommendation for a good solid commuting
tyre.
Weight is not an issue and although it's a cheap bike I'm quite happy to
splash out on decent reliable tyres. The rim is a Weinmann Zac 2000, size
700c. The old tyre is a WTB Allterrainassaurus size 32/30. The tyre only
had
about 1000 miles use and the blowout happened at a point just above where
the tyre is seated in the rim. The hole runs lengthwise round the tyre for
about 2 cms. and there are signs of wear for about 5 cms. on either side
of
the hole. So I'm wondering if maybe it was just a bad rim/tyre
combination.
There is very little sign of wear elsewhere on the tyre. I'm fairly good
about checking brakes for rubbing etc. so I don't think that was the
cause.
I've just noticed the rim is slightly out of true, maybe that contributed?
Anyway, a good commuting tyre please? I've used Conti TT and TT 2000 on my
tourer and found them to be complete *******s to get on and off its Mavic
rims. It now has Schwalbe Marathons which are showing sidewall cracks
after
c. 3000 miles. However none of these blew out or indeed punctured over
much
so if they're the panels recommendations then fine. Thanks for the help,
Tony R.


Blimey, bad luck! At least no serious damage caused, can't help with a tyre
recommendation though as I''m still getting through some Contis and you are
right about the fit on rims!

tony R wrote:

snip]. The tyre only had
about 1000 miles use and the blowout happened at a point just above where
the tyre is seated in the rim. The hole runs lengthwise round the tyre for
about 2 cms. and there are signs of wear for about 5 cms. on either side of
the hole. [snip]

Bad break block alignment and a slightly off rim?

Phil

"tony R" wrote in message
...

It now has Schwalbe Marathons which are showing sidewall cracks after
c. 3000 miles. However none of these blew out or indeed punctured over
much
so if they're the panels recommendations then fine. Thanks for the help,
Tony R.

I just got my first slow puncture after 6 months (not due to the sidewall
cracks) in my rear Marathon and today I've fitted the new Marathon Plus
which looks like one solidly built tyre.
http://www.wiggle.co.uk/v2_product_d...dID=5360007837


Front tyre is Continental Contact which is still unpunctured (with no
cracks) after 6months.

http://www.wiggle.co.uk/v2_product_d...dID=5360008372

Simon

tony R wrote:

The rim is a Weinmann Zac 2000, size 700c.

Nothing to do with your problem, but is that the same as a Rigida Zac 2000?


The old tyre is a WTB Allterrainassaurus size 32/30. The
tyre only had about 1000 miles use and the blowout happened at a point
just above where the tyre is seated in the rim. The hole runs lengthwise
round the tyre for about 2 cms. and there are signs of wear for about 5
cms. on either side of the hole. So I'm wondering if maybe it was just a
bad rim/tyre combination. There is very little sign of wear elsewhere on
the tyre. I'm fairly good about checking brakes for rubbing etc. so I
don't think that was the cause. I've just noticed the rim is slightly out
of true, maybe that contributed?

Still sounds like the brake rubbed through the tyre, especially as the load
on the front tyre is comparatively small.

The rim being out of true would explain why there were only 5 cms of wear.
You wouldn't have noticed anything unless you regularly inspected by
turning the wheel with the brake applied.


Anyway, a good commuting tyre please?

Schwalbe Marathon. Never had to change one before wearing it out.


It now has Schwalbe Marathons
which are showing sidewall cracks after c. 3000 miles.

You can quite safely ignore those. The rubber coating on the sidewalls has
no structural significance, it's mainly there to protect the fabric
underneath. As the rubber gets older, it tends to crack. In how far that
actually reduces its protective function I don't know, but anyway, you only
need to worry if the fabric itself shows any damage. But even then, in my
experience, the tyre still gives you a bit of a grace period.

Andy

Andy Koppe wrote:

Still sounds like the brake rubbed through the tyre, especially as
the load on the front tyre is comparatively small.

That's well possible but some sidewalls fail on their own through normal
use and poor design/manufacture. We can't always blame the owner.

Sorry I can't recommend a suitable tyre with particularly good sidewalls
Tony - as I'm not familiar enough with wide 700c tyres.

~PB

"Pete Biggs" wrote in message
...
Andy Koppe wrote:

Still sounds like the brake rubbed through the tyre, especially as
the load on the front tyre is comparatively small.

That's well possible but some sidewalls fail on their own through normal
use and poor design/manufacture. We can't always blame the owner.

Sorry I can't recommend a suitable tyre with particularly good sidewalls
Tony - as I'm not familiar enough with wide 700c tyres.


Thanks for all the replies. Yes it is a Rigida rim (but has Weinmann on the
sticky label). As this is the child towing, school run bike the brakes
(including alighnment) are checked weekly - I'm as sure as I can be that
that wasn't the problem. However, closer inspection has revealed that the
line of wear gradually fades out in an arc with the highest point being
where the blowout occured and the lowest being at each side at the line
where the tyre would normally be seated in the rim. I therefore think that
the tyre must have been badly seated in the rim with the rim putting
pressure on the wrong part of sidewall along this arc. I have to admit that
although I try to be careful I never thought to check for this sort of
problem before (I will now though!). The tyre was as supplied with the bike
(no punctures up 'till yesterday) and to be honest I never looked at it
closely enough to spot this problem. Is this a feasible explanation?
The LBS made my choice of tyre for me - it only had one 700c x 32 tyre in
stock a Schwalbe Marathon which I do like anyway - thanks for the
reassurance Andy.

tony R.