What else can feel like a bad bottom bracket?

"> on either BB and both failed. Got the owner involved and he agreed with

Quoted message said:

me and covered it under warranty a second time.

I'm beginning to think it's not the BB, but can't figure out what it
is. I have a lot of riding experience, built a few bikes myself, so am
pretty knowledgeable. It's not loose crank arms, that I would be able
to recognize. I also don't believe it's loose retaining nuts on the BB
because that generally also leads to a detectable motion at the pedal,
and wouldn't be restricted to 5th gear. Whatever is wrong definitely
feels like a bad bearing, but how could two cartridges be bad after
such a short time? Why is the feeling almost completely limited to 5th
gear (on any chainring)? I do ride in the rain, which is not all that
frequent in Chicago area, no limestone paths, all asphalt.

Any help welcome.

How do you know for certain it was fixed properly the first time. They said
it was filled with grit. It sure wasn't filled with grit when it left the
factory. You are sure the conditions you ride in won't fill a BB with grit
in 300miles.

I think the dealer is not being honest with you. There was no grit. The
state of your chain should be a guide to how much grit you have been riding
in. I don't think they replaced the BB either. Why would a BB filled with
grit only display symptoms in 5th gear?

I'd write to the Giant regional or national head office and explain what has
been happening to you.

It would be interesting if you could swap the wheel with another to test
that. Maybe the problem is at the rear.

Regards
Wilfred

markl said:

Symptoms:
Noticeable feeling like bad bottom bracket bearings, much more
pronounced in 5th gear, nearly undetectable in any others.

History:
New Giant Sedona DX in January. Didn't ride too much in winter but
noticed symptom developing in March. Dealer diagnosed as bad BB and
replaced under warranty. Problem went away, although I imagined I
could still feel a little something wrong in 5th gear; thought I was
just being paranoid. Six weeks later same problem develops again.
Dealer tries to charge me to replace BB, says it was filled with
grit. Told them I ride to work on asphalt every day, can't be more
than 300 miles on either BB and both failed. Got the owner involved
and he agreed with me and covered it under warranty a second time.

I'm beginning to think it's not the BB, but can't figure out what it
is. I have a lot of riding experience, built a few bikes myself, so am
pretty knowledgeable. It's not loose crank arms, that I would be able
to recognize. I also don't believe it's loose retaining nuts on the BB
because that generally also leads to a detectable motion at the pedal,
and wouldn't be restricted to 5th gear. Whatever is wrong definitely
feels like a bad bearing, but how could two cartridges be bad after
such a short time? Why is the feeling almost completely limited to
5th gear (on any chainring)? I do ride in the rain, which is not all
that frequent in Chicago area, no limestone paths, all asphalt.

Any help welcome.

Make sure it's not just "chain rub" in 5th gear? Grinding sound, vibration
felt /could/ just be the chain rubbing on the front derailleur cage, or
something in back (cable tension or limit screw adjustment). 5th cog no
bent teeth?

(There's also a trim adjustment for the FD probably; maybe shifting to 5th
gear is when you need to tap the front shift lever a bit to move the cage
out a tad?)

'luck.

BS

Wilfred Kazoks said:

How do you know for certain it was fixed properly the first time.

I'm not confident they fixed it properly the first time, but I'm 100%
sure something they did caused the symptom to either completely
disappear, or disappear to such an extent that I could barely detect
the problem.

Quoted message said:

I think the dealer is not being honest with you. There was no grit. The
state of your chain should be a guide to how much grit you have been riding
in. I don't think they replaced the BB either.

I'm reasonably sure they actually changed the BB both times because the
area right around the retaining rings was cleaned very well and there
was a nice ring of new grease around the retaining nut threads that
were exposed. I could also look in around the spindle and see the face
of the cartridge, which was also very clean. It would be almost
impossible to get things that clean without taking the cartridge out.

Quoted message said:

Why would a BB filled with
grit only display symptoms in 5th gear?

That was my original question to the dealer, and one I still have. It
always felt like this was some kind of problem with a gear. But then
why have the symptoms disappeared both times they made a repair to the
BB?

Quoted message said:

I'd write to the Giant regional or national head office and explain what has
been happening to you.

It would be interesting if you could swap the wheel with another to test
that. Maybe the problem is at the rear.

Good suggestion, maybe they would do that for me.

Quoted message said:

Regards
Wilfred

Bill Sornson said:

Make sure it's not just "chain rub" in 5th gear? Grinding sound, vibration
felt /could/ just be the chain rubbing on the front derailleur cage, or
something in back (cable tension or limit screw adjustment). 5th cog no
bent teeth?

I tried to diagnose that way with the bike on a stand, but either my
hand is not sensitive enough to pick up the grinding sensation, or it
requires the load of my body weight to cause it to happen.

Quoted message said:

(There's also a trim adjustment for the FD probably; maybe shifting to 5th
gear is when you need to tap the front shift lever a bit to move the cage
out a tad?)

I do have to trim the FD a little, but it makes a completely different
noise and one I'm familiar with. This grinding is a feeling through my
feet rather than a sound that can be heard.

loose filings in the oatmeal?

"markl" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Symptoms:
Noticeable feeling like bad bottom bracket bearings, much more
pronounced in 5th gear, nearly undetectable in any others.

History:
New Giant Sedona DX in January. Didn't ride too much in winter but
noticed symptom developing in March. Dealer diagnosed as bad BB and
replaced under warranty. Problem went away, although I imagined I could
still feel a little something wrong in 5th gear; thought I was just
being paranoid. Six weeks later same problem develops again. Dealer
tries to charge me to replace BB, says it was filled with grit. Told
them I ride to work on asphalt every day, can't be more than 300 miles
on either BB and both failed. Got the owner involved and he agreed with
me and covered it under warranty a second time.

I'm beginning to think it's not the BB, but can't figure out what it
is. I have a lot of riding experience, built a few bikes myself, so am
pretty knowledgeable. It's not loose crank arms, that I would be able
to recognize. I also don't believe it's loose retaining nuts on the BB
because that generally also leads to a detectable motion at the pedal,
and wouldn't be restricted to 5th gear. Whatever is wrong definitely
feels like a bad bearing, but how could two cartridges be bad after
such a short time? Why is the feeling almost completely limited to 5th
gear (on any chainring)? I do ride in the rain, which is not all that
frequent in Chicago area, no limestone paths, all asphalt.

Any help welcome.

I've had a simular problem, it was in what I would call 1st, but its worth a
look.
check that the teeth on the top jockey wheel of the rear derailleur aren't
hitting against the teeth of the rear sprocket through the chain. The
derailleur is pushed away every link and then springs back, it was only a
couple of mm but you could feel it.

Quoted message said:

loose filings in the oatmeal?

emery bread?

Bill Sornson said:

Quoted message said:

loose filings in the oatmeal?

emery bread?

cupcakes!

stu said:

"markl" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Symptoms:
Noticeable feeling like bad bottom bracket bearings, much more
pronounced in 5th gear, nearly undetectable in any others.

History:
New Giant Sedona DX in January. Didn't ride too much in winter but
noticed symptom developing in March. Dealer diagnosed as bad BB and
replaced under warranty. Problem went away, although I imagined I
could still feel a little something wrong in 5th gear; thought I was
just being paranoid. Six weeks later same problem develops again.
Dealer tries to charge me to replace BB, says it was filled with
grit. Told them I ride to work on asphalt every day, can't be more
than 300 miles on either BB and both failed. Got the owner involved
and he agreed with me and covered it under warranty a second time.

I'm beginning to think it's not the BB, but can't figure out what it
is. I have a lot of riding experience, built a few bikes myself, so
am pretty knowledgeable. It's not loose crank arms, that I would be
able to recognize. I also don't believe it's loose retaining nuts on
the BB because that generally also leads to a detectable motion at
the pedal, and wouldn't be restricted to 5th gear. Whatever is wrong
definitely feels like a bad bearing, but how could two cartridges be
bad after such a short time? Why is the feeling almost completely
limited to 5th gear (on any chainring)? I do ride in the rain, which
is not all that frequent in Chicago area, no limestone paths, all
asphalt.

Any help welcome.

I've had a simular problem, it was in what I would call 1st, but its
worth a look.
check that the teeth on the top jockey wheel of the rear derailleur
aren't hitting against the teeth of the rear sprocket through the
chain. The derailleur is pushed away every link and then springs
back, it was only a couple of mm but you could feel it.

The b-tension screw is what you're referring to.
--
Phil Lee, Squid

"Phil Lee, Squid" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

stu said:

"markl" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Symptoms:
Noticeable feeling like bad bottom bracket bearings, much more
pronounced in 5th gear, nearly undetectable in any others.

History:
New Giant Sedona DX in January. Didn't ride too much in winter but
noticed symptom developing in March. Dealer diagnosed as bad BB and
replaced under warranty. Problem went away, although I imagined I
could still feel a little something wrong in 5th gear; thought I was
just being paranoid. Six weeks later same problem develops again.
Dealer tries to charge me to replace BB, says it was filled with
grit. Told them I ride to work on asphalt every day, can't be more
than 300 miles on either BB and both failed. Got the owner involved
and he agreed with me and covered it under warranty a second time.

I'm beginning to think it's not the BB, but can't figure out what it
is. I have a lot of riding experience, built a few bikes myself, so
am pretty knowledgeable. It's not loose crank arms, that I would be
able to recognize. I also don't believe it's loose retaining nuts on
the BB because that generally also leads to a detectable motion at
the pedal, and wouldn't be restricted to 5th gear. Whatever is wrong
definitely feels like a bad bearing, but how could two cartridges be
bad after such a short time? Why is the feeling almost completely
limited to 5th gear (on any chainring)? I do ride in the rain, which
is not all that frequent in Chicago area, no limestone paths, all
asphalt.

Any help welcome.

I've had a simular problem, it was in what I would call 1st, but its
worth a look.
check that the teeth on the top jockey wheel of the rear derailleur
aren't hitting against the teeth of the rear sprocket through the
chain. The derailleur is pushed away every link and then springs
back, it was only a couple of mm but you could feel it.

The b-tension screw is what you're referring to.
--

not if you dont have one 😉 (but yes i guess he does)

Quoted message said:

Phil Lee, Squid

markl said:

... Why is the feeling almost completely limited to 5th
gear (on any chainring)?

There's your tipoff. It's not in the BB, it's in the rear der
adjustment. I suspect the B tension is wrong.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

Werehatrack said:

markl said:

... Why is the feeling almost completely limited to 5th
gear (on any chainring)?

There's your tipoff. It's not in the BB, it's in the rear der
adjustment. I suspect the B tension is wrong.

I would expect incorrect B tension to result in such a problem in high
(8th) gear, not 5th. How could the jockey wheel hit the cluster in 5th,
but then develop enough clearance for the 3 higher gears?

markl says...

Quoted message said:

Symptoms:
Noticeable feeling like bad bottom bracket bearings, much more
pronounced in 5th gear, nearly undetectable in any others.

History:
New Giant Sedona DX in January. Didn't ride too much in winter but
noticed symptom developing in March. Dealer diagnosed as bad BB and
replaced under warranty. Problem went away, although I imagined I could
still feel a little something wrong in 5th gear; thought I was just
being paranoid. Six weeks later same problem develops again. Dealer
tries to charge me to replace BB, says it was filled with grit. Told
them I ride to work on asphalt every day, can't be more than 300 miles
on either BB and both failed. Got the owner involved and he agreed with
me and covered it under warranty a second time.

I'm beginning to think it's not the BB, but can't figure out what it
is. I have a lot of riding experience, built a few bikes myself, so am
pretty knowledgeable. It's not loose crank arms, that I would be able
to recognize. I also don't believe it's loose retaining nuts on the BB
because that generally also leads to a detectable motion at the pedal,
and wouldn't be restricted to 5th gear. Whatever is wrong definitely
feels like a bad bearing, but how could two cartridges be bad after
such a short time? Why is the feeling almost completely limited to 5th
gear (on any chainring)? I do ride in the rain, which is not all that
frequent in Chicago area, no limestone paths, all asphalt.

Any help welcome.

Have you removed the chain and spun the BB? Any friction or looseness
should be evident. If the BB really is failing repeatedly, maybe it is
because the shell is distorted, or needs facing or tapping. Maybe what
you really need is a warranty frame. Maybe you should negotiate with
the shop to upgrade to a sealed cartridge style BB. Don't know what you
have now, but grit isn't likely to be an issue with a decent $20 BB.

Other than that, there are a variety of drivetrain issues that can cause
vibration like a frozen chain link, bent derailleur, or bent cassette
teeth. There are also more mundane reasons for this like cable
adjustment or the already mentioned B-tension. In my experience, the B-
tension adjustment has a wide range of acceptability. Have you
considered hub bearings as a possibility? Before almost every ride, I
flip my bike over and spin the wheels to check for brake rub and to make
sure the hub bearings are reasonably frictionless. I'm not familiar
with the Sedona, but house brand hubs can be the crappiest parts on an
otherwise nice bike.

On 6 Jul 2006 04:56:22 -0700, "MarkL" <[email hidden]>

Quoted message said:

Werehatrack said:

markl said:

... Why is the feeling almost completely limited to 5th
gear (on any chainring)?

There's your tipoff. It's not in the BB, it's in the rear der
adjustment. I suspect the B tension is wrong.

I would expect incorrect B tension to result in such a problem in high
(8th) gear, not 5th. How could the jockey wheel hit the cluster in 5th,
but then develop enough clearance for the 3 higher gears?

It didn't make sense to me on one of my setups, but that's what it
was. I increased the B tension, and the noise in 6th of 8 went away.
There had never been noise in 7, and I never used 8 in a situation
where noise would have been noticed.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

Barnard Frederick said:

Have you removed the chain and spun the BB?

No, but I plan to do that the next time the symptom returns.

Quoted message said:

Any friction or looseness
should be evident. If the BB really is failing repeatedly, maybe it is
because the shell is distorted, or needs facing or tapping. Maybe what
you really need is a warranty frame. Maybe you should negotiate with
the shop to upgrade to a sealed cartridge style BB. Don't know what you
have now, but grit isn't likely to be an issue with a decent $20 BB.

It came with a cartridge style BB, and that's what they replaced it
with.

Quoted message said:

Other than that, there are a variety of drivetrain issues that can cause
vibration like a frozen chain link, bent derailleur, or bent cassette
teeth. There are also more mundane reasons for this like cable
adjustment or the already mentioned B-tension. In my experience, the B-
tension adjustment has a wide range of acceptability. Have you
considered hub bearings as a possibility? Before almost every ride, I
flip my bike over and spin the wheels to check for brake rub and to make
sure the hub bearings are reasonably frictionless. I'm not familiar
with the Sedona, but house brand hubs can be the crappiest parts on an
otherwise nice bike.

I'm inclined to think it's something to do with derailleur or gears,
can't imagine the strong correlation to 5th gear otherwise.

MarkL said:

Barnard Frederick said:

Have you removed the chain and spun the BB?

No, but I plan to do that the next time the symptom returns.

Quoted message said:

Any friction or looseness
should be evident. If the BB really is failing repeatedly, maybe it
is because the shell is distorted, or needs facing or tapping.
Maybe what you really need is a warranty frame. Maybe you should
negotiate with the shop to upgrade to a sealed cartridge style BB.
Don't know what you have now, but grit isn't likely to be an issue
with a decent $20 BB.

It came with a cartridge style BB, and that's what they replaced it
with.

Quoted message said:

Other than that, there are a variety of drivetrain issues that can
cause vibration like a frozen chain link, bent derailleur, or bent
cassette teeth. There are also more mundane reasons for this like
cable adjustment or the already mentioned B-tension. In my
experience, the B- tension adjustment has a wide range of
acceptability. Have you considered hub bearings as a possibility?
Before almost every ride, I flip my bike over and spin the wheels to
check for brake rub and to make sure the hub bearings are reasonably
frictionless. I'm not familiar with the Sedona, but house brand
hubs can be the crappiest parts on an otherwise nice bike.

House brand hubs on decent bikes like LBS-brand bikes are far from being the
crappiest parts.

Quoted message said:

I'm inclined to think it's something to do with derailleur or gears,
can't imagine the strong correlation to 5th gear otherwise.

It sounds like you've known the answer from the start. Why even bother
asking the newsgroup when you knew the answer?
--
Phil Lee, Squid