Disintegrating Rims

"Mark T"
<pleasegivegenerously@warmail*turn_up_the_heat_to_reply*.com.invalid> wrote
in message news:[email hidden]...

Quoted message said:

I'd be interested if anyones had faulty rims similar to these:

A few weeks ago I bought a shiny new bike from Decathlon. Unfortunately
the rims started to disintegrate into the brake blocks - flecks of
aluminium built up until they were gouging the rim. This wasn't through
negligence on my part - the blocks were 'de-metalled' every five to ten
miles!

Wheels and brake blocks changed under warranty by Decathlon. They
apologised for the cheap 'orrible pads they gave me with the new wheels,
but it was all they had, and said I'd be welcome to change them when they
got some proper ones in. A couple of days ago I got them changed (awful
in the wet).

Now the problem of disintegrating rims has returned! I think the problem
is that the rims are faulty, but can just cope with the softer compound
of the crappy pads put on with the new wheels. The harder compound of
the Shimano pads quickly lifts specks of metal from the rim which get
embedded in the block and lift even bigger specks. The bike has done
just 5 miles with the new blocks!

The Shimano pads are just bog standard ones (M50/T on the pads, BR-
1055/A550/1500/A416/A410/4400/3300 on the packet - i.e. cheap pads for
alloy rims, not carbon, not ceramic).

I'm taking it back tomorrow and asking for a full refund as the bike is
not fit for purpose. A problem I forsee is that they've already replaced
the wheels once. Does this mean I can no longer insist on a refund under
my statutory rights?

Has anyone any better theories of why this is happening, or has had
similar problems?

It's not the rims, it's the pads. Shimano pads are notorious for wearing
rims - I'll not fit them for precisely that reason. Get some kool-stop
salmon or aztec pads and you'll be fine.

cheers,
clive

Mark T said:

I'd be interested if anyones had faulty rims similar to these:

A few weeks ago I bought a shiny new bike from Decathlon.
Unfortunately the rims started to disintegrate into the brake blocks
- flecks of aluminium built up until they were gouging the rim. This
wasn't through negligence on my part - the blocks were 'de-metalled'
every five to ten miles!

Wheels and brake blocks changed under warranty by Decathlon. They
apologised for the cheap 'orrible pads they gave me with the new
wheels, but it was all they had, and said I'd be welcome to change
them when they got some proper ones in. A couple of days ago I got
them changed (awful in the wet).

Now the problem of disintegrating rims has returned! I think the
problem is that the rims are faulty, but can just cope with the
softer compound of the crappy pads put on with the new wheels. The
harder compound of the Shimano pads quickly lifts specks of metal
from the rim which get embedded in the block and lift even bigger
specks. The bike has done just 5 miles with the new blocks!

The Shimano pads are just bog standard ones (M50/T on the pads, BR-
1055/A550/1500/A416/A410/4400/3300 on the packet - i.e. cheap pads for
alloy rims, not carbon, not ceramic).

I'm taking it back tomorrow and asking for a full refund as the bike
is not fit for purpose.

It would be ridiculous to give up on the bike for this trivial and
well-known problem - that will be solved by switching to Kool Stop Salmon
pads (and perhaps sanding the rims if they are in very bad condition). Then
you won't even have to regularly de-metal any more.

The problem is not unique to your rims. It happens even with the best rims
if the brake pads are't very good and you ride a lot in wet conditions where
grit gets on the rims and pads.

~PB

Mark T said the following on 21/12/2007 01:13:

Quoted message said:

The Shimano pads are just bog standard ones...

Get rid of the Shimano blocks and fit Kool-Stops. The Shimano blocks
eat rims for breakfast, but I think you know that :-)

--
Paul Boyd
http://www.paul-boyd.co.uk/

Mark T said:

The Shimano pads are just bog standard ones (M50/T on the pads, BR-
1055/A550/1500/A416/A410/4400/3300 on the packet - i.e. cheap pads for
alloy rims, not carbon, not ceramic).

Brilliant choice: according to Shimano "good performance in the wet, but
increased rimwear" 😉

--
/Marten

info(apestaartje)m-gineering(punt)nl

Quoted message said:

I'd be interested if anyones had faulty rims similar to these:

Most of you are of the opinion that this is normal, particularly with
Shimano brake blocks. I'm sceptical of that but will give the rims a
chance to 'bed in'.

I won't change the blocks as this may cause problems if I later want to
return the bike. Ta for the help, I'll report back after 50 to 100 miles.

"Mark T"
<pleasegivegenerously@warmail*turn_up_the_heat_to_reply*.com.invalid> wrote
in message news:[email hidden]...

Quoted message said:

Quoted message said:

I'd be interested if anyones had faulty rims similar to these:

Most of you are of the opinion that this is normal, particularly with
Shimano brake blocks. I'm sceptical of that but will give the rims a
chance to 'bed in'.

I won't change the blocks as this may cause problems if I later want to
return the bike. Ta for the help, I'll report back after 50 to 100 miles.

NO! If you don't change the brake blocks, you'll knacker your rims.

Get some better ones - I won't have shimano blocks on my bikes for exactly
that reason.

If you do want to return the bike later, you can always put the originals
back on.

Of course if you actually hate the bike and are looking for a reason to get
rid of it, go ahead. But if you want a working bike with minimal hassle, get
some new pads and put them on.

cheers,
clive

On 21/12/2007 16:25, Mark T said,

Quoted message said:

Most of you are of the opinion that this is normal, particularly with
Shimano brake blocks. I'm sceptical of that but will give the rims a
chance to 'bed in'.

Your choice, but the rims won't 'bed in' - they'll blow out eventually
if you keep using those Shimano blocks. Remember, you were the one who
asked for advice :-)

--
Paul Boyd
http://www.paul-boyd.co.uk/

Quoted message said:

NO! If you don't change the brake blocks, you'll knacker your rims.

Get some better ones - I won't have shimano blocks on my bikes for
exactly that reason.

If you do want to return the bike later, you can always put the
originals back on.

The rims are already damaged so I don't want to keep them. Keeping the
pads on for more than 5 miles will prove to the shop that there is indeed a
problem with the rims (I think I've done a bad job at explaining how fast
the rims are getting damaged). There is a chance that everything will sort
itself out, but on current experience I doubt it :-(

Mark T said:

Quoted message said:

I'd be interested if anyones had faulty rims similar to these:

Most of you are of the opinion that this is normal, particularly with
Shimano brake blocks. I'm sceptical of that but will give the rims a
chance to 'bed in'.

I won't change the blocks as this may cause problems if I later want to
return the bike. Ta for the help, I'll report back after 50 to 100 miles.

You're making a mistake. Shimano pads are designed to perform well in the
conditions experienced in Shimano's main markets - which is to say, warm,
dry conditions. They're not designed to - and don't - work well in cool,
damp conditions. They will continue to eat your rims. There's nothing wrong
with your bike or your rims, but the pads are not going to work well unless
you move to the Mediterranean - or California.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; have mercy on the slender grass

Mark T said:

Quoted message said:

NO! If you don't change the brake blocks, you'll knacker your rims.

Get some better ones - I won't have shimano blocks on my bikes for
exactly that reason.

If you do want to return the bike later, you can always put the
originals back on.

The rims are already damaged so I don't want to keep them.

There is no need to replace the rims if they have plenty of life left and
the pads are changed. You can measure the thickness to check.

Quoted message said:

Keeping
the pads on for more than 5 miles will prove to the shop that there
is indeed a problem with the rims (I think I've done a bad job at
explaining how fast the rims are getting damaged). There is a chance
that everything will sort itself out, but on current experience I
doubt it :-(

Your experience doesn't include trying good pads. Why not take advice from
those who have experienced the same problem and found the solution? I think
it's because you're more interested in getting what you see as justice from
the bike shop for the sake of it than finding a real soloution that will
enable you to enjoy this bike.

You want to deliberately wear out the rims prematurely in an attempt to get
the whole bike replaced. That's not something I want to help with.

~PB

Quoted message said:

Quoted message said:

The rims are already damaged so I don't want to keep them.

There is no need to replace the rims if they have plenty of life left
and the pads are changed. You can measure the thickness to check.

The rims have many small flecks of metal on the surface waiting to come
off. I'm not confident that going to softer pads will prevent these from
being dislodged into the pads and the whole cycle starting again,
especially as I'm told that the recommended Kool Stops are also a hard
compound.

Quoted message said:

Your experience doesn't include trying good pads. Why not take advice
from those who have experienced the same problem and found the
solution? I think it's because you're more interested in getting what
you see as justice from the bike shop for the sake of it than finding
a real soloution that will enable you to enjoy this bike.

From reading the posts and googling it seemed that many have experienced
a similar problem, but not at such an extreme rate. Your post mentioned
that it happens a lot when grit gets between rim and pad, but there was
no grit to start the process off in this case. Google brought up
instances of people complaining about similar happening under sustained
braking, but it's happening to me under moderate braking. The
(different) pads that came with the bike did the same, and they seemed
softer than the current ones, so I'm not certain that Kool Stops (or
another good quality brand) will be an improvement.

It's prolly worth pointing out that the Shimano pads are fitted in their
workshop to many of the bikes they fix, so I'm very sceptical that wear
at this rate is often the case for these known 'rim eaters'. I think
I've done a bad job at explaining the rate of wear I've experienced.

Quoted message said:

You want to deliberately wear out the rims prematurely in an attempt
to get the whole bike replaced. That's not something I want to help
with.

I'd like to go back to the shop and show them what the problem is without
being fobbed off. This would mean being able to demonstrate the problem
rather than explain it. Given the rapidity of the damage I'm not
inclined to spend my time testing different brands of brake block - two
sets of rims have failed to work with two different brands of brake block
so at this point I'd rather just walk away.

Decathlon is a large multinational company, so whereas I'd have more time
for a traditional local bike shop, I feel no obligation to save Decathlon
the money. Getting replacement pads from them would also be problematic
- I obviously wouldn't accept either of the three brands of pads the bike
has so far had.

Quoted message said:

You're making a mistake. Shimano pads are designed to perform well in
the conditions experienced in Shimano's main markets - which is to
say, warm, dry conditions. They're not designed to - and don't - work
well in cool, damp conditions.

They're described as being good in the rain, but you could be right about
it being the cool conditions that contribute to it.

Simon Brooke said:

You're making a mistake. Shimano pads are designed to perform well in the
conditions experienced in Shimano's main markets - which is to say, warm,
dry conditions. They're not designed to - and don't - work well in cool,
damp conditions.

Well.. I still have the original Shimano pads on my bike, and they've
not eaten the rims at all. They've been on it for several thousand
miles, and 1500 this year (and I've been rained on a few times).

Only my rear wheel has been changed (after being hit by a car). The
front is original, and I see no sign of rim wear.

--
From the sunny Isle of Man.
Yes, the Reply-To email address is valid.

Mark T said:

Quoted message said:

Quoted message said:

The rims are already damaged so I don't want to keep them.

There is no need to replace the rims if they have plenty of life left
and the pads are changed. You can measure the thickness to check.

The rims have many small flecks of metal on the surface waiting to
come off. I'm not confident that going to softer pads will prevent
these from being dislodged into the pads and the whole cycle starting
again, especially as I'm told that the recommended Kool Stops are
also a hard compound.

Lightly sanding the rims will dislodge any flecks of metal that are about to
come off, then fit Kool Stops. There is still a chance you'll get one or
two flecks at first - but it won't be enough to start the cycle again if you
remove them promptly. The rims don't have to be in perfect condition for
the problem to stop, in my experience.

Kool Stop market their compound as "rim friendly" - and that's not
marketing BS in this case. I'm not really sure if it's hard or soft. It
seems denser
and more rubbery than most and specks of grit and metal are not so able to
get stuck in it. That's the important thing.

Quoted message said:

Quoted message said:

Your experience doesn't include trying good pads. Why not take
advice from those who have experienced the same problem and found the
solution? I think it's because you're more interested in getting
what you see as justice from the bike shop for the sake of it than
finding a real soloution that will enable you to enjoy this bike.

From reading the posts and googling it seemed that many have
experienced a similar problem, but not at such an extreme rate. Your
post mentioned that it happens a lot when grit gets between rim and
pad, but there was no grit to start the process off in this case.

I suspect other people's experiences are closer to yours than you think.
I've had the probem myself after just a few dry gentle miles with new rims,
then metal found in the pads. Grit comes from the road - more so when it's
wet, but also when dry. If grit is not to blame, however, the pads are!

Quoted message said:

Google brought up instances of people complaining about similar
happening under sustained braking, but it's happening to me under
moderate braking.

You'll also find complaints where people haven't specified what sort of
braking they do. I've had it happen under light braking as well.

Quoted message said:

The (different) pads that came with the bike did
the same, and they seemed softer than the current ones, so I'm not
certain that Kool Stops (or another good quality brand) will be an
improvement.

Most brake pads are similar to each other and [censored]. It's very common indeed
for them to get bits of metal stuck them. Most people don't realise or
don't care.

The Kool Stop compound is quite different from the many other brands I've
used.

Quoted message said:

It's prolly worth pointing out that the Shimano pads are fitted in
their workshop to many of the bikes they fix,

They are stupid then.

Quoted message said:

so I'm very sceptical
that wear at this rate is often the case for these known 'rim
eaters'.
I think I've done a bad job at explaining the rate of wear
I've experienced.

By what percentage has the rim thickness decreased, and over how long? Have
you measured the sidewall thickness?

Quoted message said:

Quoted message said:

You want to deliberately wear out the rims prematurely in an attempt
to get the whole bike replaced. That's not something I want to help
with.

I'd like to go back to the shop and show them what the problem is
without being fobbed off. This would mean being able to demonstrate
the problem rather than explain it.

Your cycling will be spoilt in the meantime and you'll have stress arguing
with the shop.

Quoted message said:

Given the rapidity of the damage
I'm not inclined to spend my time testing different brands of brake
block - two sets of rims have failed to work with two different
brands of brake block so at this point I'd rather just walk away.

Other people have done the testing for you! We've tried many brands over
many years and finally found THE good one! It took me twenty bloody years
to discover it!

Quoted message said:

Decathlon is a large multinational company, so whereas I'd have more
time for a traditional local bike shop, I feel no obligation to save
Decathlon the money. Getting replacement pads from them would also
be problematic - I obviously wouldn't accept either of the three
brands of pads the bike has so far had.

Buy the pads yourself and put it down to experience.

If Kool Stop Dura Salmon or Dual type, I will happily buy them off you if
they don't solve the problem - no matter what condition they are in.

~PB

Dylan Smith said:

Simon Brooke said:

You're making a mistake. Shimano pads are designed to perform well
in the conditions experienced in Shimano's main markets - which is
to say, warm, dry conditions. They're not designed to - and don't -
work well in cool, damp conditions.

Well.. I still have the original Shimano pads on my bike, and they've
not eaten the rims at all. They've been on it for several thousand
miles, and 1500 this year (and I've been rained on a few times).

Only my rear wheel has been changed (after being hit by a car). The
front is original, and I see no sign of rim wear.

I don't think it proves anything important that not everyone gets obvious
problems with Shimano pads. The point is that a lot of people do - and they
find switching to better pads solves the problems.

I suspect your rim is somewhat worn though - perhaps it's just that it's
worn nice and smoothly.

~PB

"Mark T" wrote in message news:[email hidden]...

Quoted message said:

They're described as being good in the rain, but you could be right about
it being the cool conditions that contribute to it.

Shimano pads? They are having a laugh. I'm using Koolstop Salmon and Blacks
and they stop quicker and I don't have to clean the rims every day, which I
had to in the wet with stock shimanos.

Jc.

In article <[email hidden]>, Pete Biggs
[email hidden] says...

Quoted message said:

Other people have done the testing for you! We've tried many brands over
many years and finally found THE good one! It took me twenty bloody years
to discover it!

Heh, 20 years ago I was using Scott-Mathauser brake blocks - pink ones,
made by Kool Stop. :-) I sold the bike they were on, but if it's still
going I wouldn't be surprised if they are too.

Rob Morley said:

In article <[email hidden]>, Pete Biggs
[email hidden] says...

Quoted message said:

Other people have done the testing for you! We've tried many brands
over many years and finally found THE good one! It took me twenty
bloody years to discover it!

Heh, 20 years ago I was using Scott-Mathauser brake blocks - pink
ones, made by Kool Stop. :-) I sold the bike they were on, but if
it's still going I wouldn't be surprised if they are too.

Yebut I had never heard of Scott-Mathauser 20 years ago. In fact I'd never
heard of very much until I got online ;-) - less than eight years ago

~PB

In article <[email hidden]>, Pete Biggs
[email hidden] says...

Quoted message said:

Yebut I had never heard of Scott-Mathauser 20 years ago. In fact I'd never
heard of very much until I got online ;-) - less than eight years ago

Before the interweb we relied on paper magazines, catalogues that were
delivered by snail mail, and shops that you had to actually physically
travel to - the knowledge was mostly there to be had, just not at the
touch of a button. In those days conversation usually involved mouths
and ears, normally in the same room and in real time. How primitive
this seems to us now. :-)