unusual blow out

out riding today at world record pace(read pb lol), when the back tyre let go. get the back wheel
off, find the hole, look at the tyre and there is a hole about an inch long just above the bead but
below the top of the rim. looking around the rest of the tyre, it has worn through to the canvas
about 20% of the way around on both sides the tyre has done about 800 miles and was almost worn out
anyway they are the cheapest MTB tyre the LBS has l normally run them at max pressure now for my
questions was it just a bad tyre? was it because it was a cheap tyre? or does this just happen on
MTB tyres? as l say, l can't see the wear while the tyre is on the rim and l would rather that the
front tyre didn't go the same way any ideas? l only have 1800 miles of MTB experience and haven't
seen this before thanks

 

"stu" <[email protected]> wrote:

>out riding today at world record pace(read pb lol), when the back tyre let go. get the back wheel
>off, find the hole, look at the tyre and there is a hole about an inch long just above the bead but
>below the top of the rim. looking around the rest of the tyre, it has worn through to the canvas
>about 20% of the way around on both sides the tyre has done about 800 miles and was almost worn out
>anyway they are the cheapest MTB tyre the LBS has l normally run them at max pressure now for my
>questions was it just a bad tyre? was it because it was a cheap tyre? or does this just happen on
>MTB tyres? as l say, l can't see the wear while the tyre is on the rim and l would rather that the
>front tyre didn't go the same way any ideas? l only have 1800 miles of MTB experience and haven't
>seen this before thanks

I'm guessing the brake pads were misaligned and wore through the sidewall. If you can see the "wear"
with the tire mounted, that's almost certainly what caused the damage.

Mark Hickey Habanero Cycles http://www.habcycles.com Home of the $695 ti frame

 

On Fri, 02 May 2003 17:58:44 +1000, stu wrote:

> out riding today at world record pace(read pb lol), when the back tyre let go. get the back wheel
> off, find the hole, look at the tyre and there is a hole about an inch long just above the bead
> but below the top of the rim. looking around the rest of the tyre, it has worn through to the
> canvas about 20% of the way around on both sides the tyre has done about 800 miles and was almost
> worn out anyway they are the cheapest MTB tyre the LBS has l normally run them at max pressure now
> for my questions

Are the brake blocks contacting the rim squarely, or might they rub against the tire? That is, of
course, bad.

> was it just a bad tyre?

??

> was it because it was a cheap tyre?

Probably not.

> or does this just happen on MTB tyres?

It shouldn't happen to any tire unless the brakes rub on it.

--

David L. Johnson

__o | When you are up to your ass in alligators, it's hard to remember _`\(,_ | that your initial
objective was to drain the swamp. -- LBJ (_)/ (_) |

 

thanks guys, but l am pretty sure that it is to low to be the brake pads(l will put it back on later
today just to be sure). The wear seems to be between the rim and the tyre. (there you go Jobst, the
T is just for you)

 

Do yourself a favor: Remove the front tire and look for the same problem, because if you're riding
at "world record pace" and your front tire blows, you could lose control and crash big time.

stu wrote:

> out riding today at world record pace(read pb lol), when the back tyre let go. get the back wheel
> off, find the hole, look at the tyre and there is a hole about an inch long just above the bead
> but below the top of the rim. looking around the rest of the tyre, it has worn through to the
> canvas about 20% of the way around on both sides the tyre has done about 800 miles and was almost
> worn out anyway they are the cheapest MTB tyre the LBS has l normally run them at max pressure now
> for my questions was it just a bad tyre? was it because it was a cheap tyre? or does this just
> happen on MTB tyres? as l say, l can't see the wear while the tyre is on the rim and l would
> rather that the front tyre didn't go the same way any ideas? l only have 1800 miles of MTB
> experience and haven't seen this before thanks

 

"stu" <[email protected]> wrote in message news:[email protected]...
> out riding today at world record pace(read pb lol), when the back tyre let go. get the back
> wheel off, find the hole, look at the tyre and there is a hole about an inch long just above the
> bead but below the top of the rim. looking around the rest of the tyre, it has worn through to
> the canvas
about
> 20% of the way around on both sides the tyre has done about 800 miles and was almost worn out
> anyway they are the cheapest MTB tyre the LBS has l normally run them at max pressure now for my
> questions was it just a bad tyre? was it because it was a cheap tyre? or does this just happen on
> MTB tyres? as l say, l can't see the wear while the tyre is on the rim and l would rather that the
> front tyre didn't go the same way any ideas? l only have 1800 miles of MTB experience and haven't
> seen this before thanks
>
>

Double check to see if the brake shoes are inching over the top of the rim. That's not unusual and
occurs for a variety of reasons on various brake designs. Be sure to oil the threads of the shoe or
shoe holder so they stay where you want them! Some brake designs ( see FAQ) inherently creep upwards
with shoe wear and warrant periodic inspection.

--
Andrew Muzi http://www.yellowjersey.org Open every day since 1 April 1971

 

have just checked and it is definitely not the brakes the wear is just above the bead but below the
edge of the rim (i.e you can't see it without letting the tyre down) all 5 tyres l have show wear in
this area the one that blew out an old worn out one(this was so close to blowing out that if you
hold it up to the light there is a line of pin holes) my front tyre and both the ones on the misses
bike (about 1000 miles) the tyres are 26*1.95, but the rim has 26*1.50 on it, although it is only 1
inch wide (this is how the bikes came) is this a problem? some spare tyres l bought are 2.10 would
that be a problem? they aren't the cheapest bikes in the world, but l think the tyres could be.
called Kenda made in Taiwan, the spares are Maxxis made in china, although they look pretty much the
same both bikes are ridden mostly on bike paths, although mine gets off road once in a while

 

Are you overinflating the tires? Underinflating? Is there a rough spot on the walls of the rim that
is wearing down the tire?

stu wrote:

> have just checked and it is definitely not the brakes the wear is just above the bead but below
> the edge of the rim (i.e you can't see it without letting the tyre down) all 5 tyres l have show
> wear in this area the one that blew out an old worn out one(this was so close to blowing out that
> if you hold it up to the light there is a line of pin holes) my front tyre and both the ones on
> the misses bike (about 1000 miles) the tyres are 26*1.95, but the rim has 26*1.50 on it, although
> it is only 1 inch wide (this is how the bikes came) is this a problem? some spare tyres l bought
> are 2.10 would that be a problem? they aren't the cheapest bikes in the world, but l think the
> tyres could be. called Kenda made in Taiwan, the spares are Maxxis made in china, although they
> look pretty much the same both bikes are ridden mostly on bike paths, although mine gets off road
> once in a while

 

"stu" <[email protected]> wrote in message news:[email protected]...
> have just checked and it is definitely not the brakes the wear is just above the bead but below
> the edge of the rim (i.e you
can't
> see it without letting the tyre down) all 5 tyres l have show wear in this area the one that blew
> out an old worn out one(this was so close to blowing out that if you hold it
up
> to the light there is a line of pin holes)

I have seen this problem with some rims.

In my experience, what you are seeing is due to a flattened/sharpened clincher hook. This flattening
is likely a result of the rolling operation (part of the manufacturing process).

What kind of rim are you using?

--
=======================
Kraig Willett Special RBT Subscription Rates: www.biketechreview.com/rbt.htm
=======================

 

l run 65psi which is the maximum pressure on the tyre and have just checked my pressure gauges and
all 3 agree with in a few psi.The rims are TEAM A l guess it is just something l will have to keep
an eye on and hope the new tyres fix it (l cant get the old type anymore anyway, maybe l know why
now lol) is there a problem putting a 2.1 tyre on a rim that is only 1 inch wide?

 

have just looked on sheldons page and it seams my old tyres were pushing the
limit.l measure the rim width at 19.6mm so 1.95inch tyres are pushing the limit already. could that
be the problem?? looks like the 2.1inch tryes will have to wait in the shed for another day

 

"stu" <[email protected]> wrote in message news:<[email protected]>...
> have just looked on sheldons page and it seams my old tyres were pushing the
> limit.l measure the rim width at 19.6mm so 1.95inch tyres are pushing the limit already. could
> that be the problem?? looks like the 2.1inch tryes will have to wait in the shed for another
> day

My bicycle experience is old. 25 years. Just some thoughts:

1) This should not be happening.

2) It is very bad (and expensive).

3) When you check the brakes, try to load them up by pushing the bike forward while applying them
to see if they "cock" in a way that causes them to touch the tire under load (this may take
two people).

4) Check the earlier posters notion that there could be a sharp edge or burr on the rim. This is an
easy one since it can be fixed with a fine file and emery cloth (with the tire and tube removed).

5) Failing these,I would replace the rims with good ones the right width.

6) Persevere.

Peter Crawford