Problem with wheel destroying tyre

Pete Biggs

Proper Dave wrote:
> I have an odd problem (at least I've never heard of it before) in that
> my rear wheel rim has destroyed the tyre that was on it.
>
> I noticed small threads of rubber near the rim but it eventually got
> to the stage where all the rubber where the rim edge makes contact
> with the tyre has worn away and there are holes in the casing.
>
> The odd thing is that this is the second time this has happened with
> this bike although the first time was with a different rim!
>
> In nearly 50 years of cycling I have never had this problem and never
> heard of anyone else having it.
>
>
> The rims are smooth and free from corrosion and the tyres were not
> over inflated. The front tyre, which runs at the same pressure, shows
> no signs of the problem.
>
> The tyres are Schwalbe city jets. I think they're about a year old and
> there is plenty of rubber left where the tread would be (they are
> virtualy slicks so there's no actual tread.

It's not all that uncommon for the tyres to get chafed, and that's why some
have anti-chafing tape incorporated.

Under-inflation makes the problem worse as it allows the tyre to flex more.
So consider using higher pressure if you think your tyres may be a bit on
the soft side (judge with thumbs rather than a gauge). Otherwise try a
different make or model of tyre.

~PB

Pete Biggs

Proper Dave wrote:

> The rims are smooth and free from corrosion and the tyres were not
> over inflated. The front tyre, which runs at the same pressure, shows
> no signs of the problem.

The rear tyre takes more weight than the front, so it should be run at a
higher pressure. With the same pressure, the front will be flexing less
than the rear. This could explain why you're not having a problem with the
front.

~PB

Pete Biggs

Proper Dave wrote:

> Is there any significance to the way the rubber seems to 'erode' in
> very fine threads?

No, there's hardly any significance to the rubber on the sidewalls at all as
it doesn't do much. Tyres can be fine without any rubber on the sides.
It's the casing underneath that is important to the structure.

My brother used City Jets on his mountain bike. They are generally good
tyres, but there was eventually a problem with one of the sidewalls. I
can't remember what that was exactly.

Anyway, I think you should try different tyres now. People will make
suggestions if you mention the size required. 26 x 1.5"?

~PB

Proper Dave

I have an odd problem (at least I've never heard of it before) in that
my rear wheel rim has destroyed the tyre that was on it.

I noticed small threads of rubber near the rim but it eventually got to
the stage where all the rubber where the rim edge makes contact with the
tyre has worn away and there are holes in the casing.

The odd thing is that this is the second time this has happened with
this bike although the first time was with a different rim!

In nearly 50 years of cycling I have never had this problem and never
heard of anyone else having it.

The rims are smooth and free from corrosion and the tyres were not over
inflated. The front tyre, which runs at the same pressure, shows no
signs of the problem.

The tyres are Schwalbe city jets. I think they're about a year old and
there is plenty of rubber left where the tread would be (they are
virtualy slicks so there's no actual tread.

Any help appreciated.

Roger Thorpe

Proper Dave wrote:

> I have an odd problem (at least I've never heard of it before) in that
> my rear wheel rim has destroyed the tyre that was on it.
>
> I noticed small threads of rubber near the rim but it eventually got to
> the stage where all the rubber where the rim edge makes contact with the
> tyre has worn away and there are holes in the casing.
>
> The odd thing is that this is the second time this has happened with
> this bike although the first time was with a different rim!
>
> In nearly 50 years of cycling I have never had this problem and never
> heard of anyone else having it.
>
> The rims are smooth and free from corrosion and the tyres were not over
> inflated. The front tyre, which runs at the same pressure, shows no
> signs of the problem.
>
> The tyres are Schwalbe city jets. I think they're about a year old and
> there is plenty of rubber left where the tread would be (they are
> virtualy slicks so there's no actual tread.
>
> Any help appreciated.

The usual suspect in this case would be brake blocks that are worn or
badly adjusted, and strike the tyre. Assuming that this is not the case,
then you might wonder if the tyres were *under* inflated and therefore
flexing at that point excessively.

Roger Thorpe

Proper Dave

On Thu, 19 Jun 2008 12:42:20 +0100, Roger Thorpe
<myinitial.mysrname@warwick.ac.uk> wrote:

>Proper Dave wrote:
>
>> I have an odd problem (at least I've never heard of it before) in that
>> my rear wheel rim has destroyed the tyre that was on it.
>>
>> I noticed small threads of rubber near the rim but it eventually got to
>> the stage where all the rubber where the rim edge makes contact with the
>> tyre has worn away and there are holes in the casing.
>>
>> The odd thing is that this is the second time this has happened with
>> this bike although the first time was with a different rim!
>>
>> In nearly 50 years of cycling I have never had this problem and never
>> heard of anyone else having it.
>>
>> The rims are smooth and free from corrosion and the tyres were not over
>> inflated. The front tyre, which runs at the same pressure, shows no
>> signs of the problem.
>>
>> The tyres are Schwalbe city jets. I think they're about a year old and
>> there is plenty of rubber left where the tread would be (they are
>> virtualy slicks so there's no actual tread.
>>
>> Any help appreciated.
>
>The usual suspect in this case would be brake blocks that are worn or
>badly adjusted, and strike the tyre. Assuming that this is not the case,
>then you might wonder if the tyres were *under* inflated and therefore
>flexing at that point excessively.

The location of the rubber removal is where the tyre touches the rim -
you can't see that the rubber is actually missing until you remove the
tyre, so I don't think it's brake blocks (which I check regularly anyway
because the chap in the shop mentioned this when the other tyre went).

As to inflation, I always keep the tyres inflated to the maximum rated
pressure because the road from my house is APPALLING (and the bike is
faster that way). So they are inflated so hard that you can't make any
impression between your thumb and fingers - they feel like iron.

What I find odd is that I've never had this problem before.

Is there any significance to the way the rubber seems to 'erode' in very
fine threads?

Proper Dave

On Thu, 19 Jun 2008 13:17:09 +0200, "Pete Biggs"
<p@pomegranateremovehighlyimpracticalfruitbiggs.tc> wrote:

>Proper Dave wrote:
>
>> Is there any significance to the way the rubber seems to 'erode' in
>> very fine threads?
>
>No, there's hardly any significance to the rubber on the sidewalls at all as
>it doesn't do much. Tyres can be fine without any rubber on the sides.
>It's the casing underneath that is important to the structure.
>
>My brother used City Jets on his mountain bike. They are generally good
>tyres, but there was eventually a problem with one of the sidewalls. I
>can't remember what that was exactly.
>
>Anyway, I think you should try different tyres now. People will make
>suggestions if you mention the size required. 26 x 1.5"?

OK, thanks.

Yes, that's the size.

Preferably with as little tread as possible.

Tim Hall

On Thu, 19 Jun 2008 12:42:20 +0100, Roger Thorpe
<myinitial.mysrname@warwick.ac.uk> wrote:

<snip>
>
>The usual suspect in this case would be brake blocks that are worn or
>badly adjusted, and strike the tyre.
>

Seconded. I've had this problem. Check _very carefully_ that the
brake block contacts only the rim. In my case the upper edge of the
block was,initially, in thin air. As the block wore down overtime,
that part in thin air didn't wear. This led to a ridge on the upper
edge of the block in a perfect position to wear away atthe edge of te
tyre.



--

Tim

I understand very little of what's being discussed
but for some reason it's fascinating.

(Jon Thompson, urs)

Proper Dave

On Thu, 19 Jun 2008 13:43:01 +0100, Tim Hall
<timhall@nospamtoday.clara.co.uk> wrote:

>On Thu, 19 Jun 2008 12:42:20 +0100, Roger Thorpe
><myinitial.mysrname@warwick.ac.uk> wrote:
>
><snip>
>>
>>The usual suspect in this case would be brake blocks that are worn or
>>badly adjusted, and strike the tyre.
>>
>
>Seconded. I've had this problem. Check _very carefully_ that the
>brake block contacts only the rim. In my case the upper edge of the
>block was,initially, in thin air. As the block wore down overtime,
>that part in thin air didn't wear. This led to a ridge on the upper
>edge of the block in a perfect position to wear away atthe edge of te
>tyre.

Well, I treble checked and there is no way the brake blocks are making
contact with the tyre. They make contact with the inner part of the rim
edge. Having had that suggested as a possible cause last time I'm
particularly careful.

Also, as I said, the area where the rubber is missing is acutally
invisible with the tyre inflated on the rim.

Mark T

Proper Dave writtificated

> As to inflation, I always keep the tyres inflated to the maximum rated
> pressure because the road from my house is APPALLING (and the bike is
> faster that way).

On poor road surfaces lower pressures are likely to be both more
comfortable and more efficient. Apologies if I've just taught you to suck
eggs.

> So they are inflated so hard that you can't make any
> impression between your thumb and fingers - they feel like iron.

Do you know what pressures you run them at?

Proper Dave

On 19 Jun 2008 20:57:27 GMT, Mark T
<pleasegivegenerously@warmail*turn_up_the_heat_to_reply*.com.invalid>
wrote:

>Proper Dave writtificated
>
>> As to inflation, I always keep the tyres inflated to the maximum rated
>> pressure because the road from my house is APPALLING (and the bike is
>> faster that way).
>
>On poor road surfaces lower pressures are likely to be both more
>comfortable and more efficient. Apologies if I've just taught you to suck
>eggs.

They are inflated hard because:

1) It stops the tyre 'collapsing' to the point the rim hits the road
(through the tyre).

2) The road from my house is only 5 - 10% of an average journey.

>> So they are inflated so hard that you can't make any
>> impression between your thumb and fingers - they feel like iron.
>
>Do you know what pressures you run them at?

Of course. (Assuming the gauge on the pump is correct - one day I must
try and get one of those very basic car tyre gauges to verify the pump
guage).

Mark T

Proper Dave writtificated

>>Do you know what pressures you run them at?
>
> Of course. (Assuming the gauge on the pump is correct - one day I must
> try and get one of those very basic car tyre gauges to verify the pump
> guage).

I meant "what pressures do you run them at?"

Rob Morley

On 19 Jun 2008 20:57:27 GMT
Mark T
<pleasegivegenerously@warmail*turn_up_the_heat_to_reply*.com.invalid>
wrote:

> Proper Dave writtificated
>
> > As to inflation, I always keep the tyres inflated to the maximum
> > rated pressure because the road from my house is APPALLING (and the
> > bike is faster that way).
>
> On poor road surfaces lower pressures are likely to be both more
> comfortable and more efficient.

To a point, after which it feels soggy and endangers rims and sidewalls.

Jhimmy

"Proper Dave" <ProperDave@nospam.com> wrote in message
news:485a8fff.34557531@news.individual.NET...
> On Thu, 19 Jun 2008 13:43:01 +0100, Tim Hall
> <timhall@nospamtoday.clara.co.uk> wrote:
>
>>On Thu, 19 Jun 2008 12:42:20 +0100, Roger Thorpe
>><myinitial.mysrname@warwick.ac.uk> wrote:
>>
>><snip>
>>>
>>>The usual suspect in this case would be brake blocks that are worn or
>>>badly adjusted, and strike the tyre.
>>>
>>
>>Seconded. I've had this problem. Check _very carefully_ that the
>>brake block contacts only the rim. In my case the upper edge of the
>>block was,initially, in thin air. As the block wore down overtime,
>>that part in thin air didn't wear. This led to a ridge on the upper
>>edge of the block in a perfect position to wear away atthe edge of te
>>tyre.
>
> Well, I treble checked and there is no way the brake blocks are making
> contact with the tyre. They make contact with the inner part of the rim
> edge. Having had that suggested as a possible cause last time I'm
> particularly careful.
>
> Also, as I said, the area where the rubber is missing is acutally
> invisible with the tyre inflated on the rim.
>

As nobody so far has any idea, this could be a case of elimination.

As it's a MTB/Hybrid tyre is the inner tube suitable for 1.5, I'd imagine if
it's 2.1 then a bulge in the main tyre could cause the tyre rim to somehow
raise from the wheel rim, especially as the pressure sounds high for a 26"
wheel. I've 26 x1.5 tyres and I think I only have them at 45 psi and only
had 1 puncture in the last 18 months (about 1500 miles) in rough and glass
covered roads.

Usually at work we always say (when something breaks down) what's been added
or removed from the working configuration to the broken one. even something
as simple as a different size or make of inner tube can make a difference.

Other things could be is the wheel true and the spokes properly tensioned? A
LBS would be best to check that.


Jhimmy