Help Identify BB 'Clunking' Noise Please!

[John Latter]

Hi,

I brought an Argos 'Boss Reflex' cycle for £129 in November
which I exchanged (for the same model) two weeks ago because
of bottom bracket bearing problems.

Now the new bike is playing up! First I got side-to-side
play from the cranks which a friendly Halfords engineer
sorted out for me (apparently the bb mechanism consists of
component parts which is the old way of doing things).

The latest problem (which I hope you can help me with) is a
distinct 'clunking' sound which happens in all gears and is
mostly associated with any pressure on the right hand pedal
(where the three chain thingies are) when it is at the top
of its 'orbit'.

Er, I'm not very knowledgeable about bikes, nor very good at
describing symptoms, but I hope the foregoing may make some
sense to somebody!

I also hope its easy for someone like me to sort out

Thankyou in advance,

--

John Latter

Model of an Internal Evolutionary Mechanism (based on an
extension to homeostasis) linking Stationary-Phase Mutations
to the Baldwin Effect.
http://members.aol.com/jorolat/TEM.html

'Where Darwin meets Lamarck?' Discussion Egroup
http://groups.yahoo.com/group/evomech

 

[Tony Raven]

John Latter wrote:
>
> The latest problem (which I hope you can help me with) is
> a distinct 'clunking' sound which happens in all gears and
> is mostly associated with any pressure on the right hand
> pedal (where the three chain thingies are) when it is at
> the top of its 'orbit'.
>

There are lots of things it could be including a loose
pedal, the crank loose on the bottom bracket spindle or a
loose bottom bracket. Try tightening them all up and see if
it goes away. FWIW I would spend the £15 to get a Shimano
UN52 bottom bracket fitted if you currently have a component
one - the Shimano ones are fit and forget.

Tony

 

[David Kenning]

John Latter wrote:
> (apparently the bb mechanism consists of component parts
> which is the old way of doing things).

Yup, that's right. Mine's the same.

> Er, I'm not very knowledgeable about bikes, nor very good
> at describing symptoms, but I hope the foregoing may make
> some sense to somebody!

I'm no expert either, but... Is the crank loose where it
attaches to the BB axle? If not, then I'd guess it most
probably is another bearing problem. Or it could be the
axle that's worn, especially if you had the bearings
replaced recently.

> I also hope its easy for someone like me to sort out

I think fixing it is one of those jobs that is not all that
difficult but requires some fairly specialised tools -
namely a 'C' spanner, for removing the bracket locking nuts,
and a crank extractor for, er, extracting the cranks.

d.

 

[Just Zis Guy]

On Sun, 28 Mar 2004 16:18:48 +0100, "Tony Raven"
<[email protected]> wrote in message
<[email protected]>:

>FWIW I would spend the £15 to get a Shimano UN52 bottom
>bracket fitted if you currently have a component one - the
>Shimano ones are fit and forget.

The UN72 might be, but I wore out a UN52 in under a year.

--
Guy
===
May contain traces of irony. Contents liable to settle after
posting. http://www.chapmancentral.co.uk

88% of helmet statistics are made up, 65% of them at
Washington University

 

[Simon Daw]

"david kenning" <[email protected]> wrote in message
news:[email protected]...
> John Latter wrote:
> > (apparently the bb mechanism consists of component parts
> > which is the old way of doing things).
>
> Yup, that's right. Mine's the same.
>
> > Er, I'm not very knowledgeable about bikes, nor very
> > good at describing symptoms, but I hope the foregoing
> > may make some sense to somebody!
>
> I'm no expert either, but... Is the crank loose where it
> attaches to the
BB
> axle? If not, then I'd guess it most probably is another
> bearing problem.
Or
> it could be the axle that's worn, especially if you had
> the bearings replaced recently.
>
> > I also hope its easy for someone like me to sort out
>
> I think fixing it is one of those jobs that is not all
> that difficult but requires some fairly specialised tools
> - namely a 'C' spanner, for
removing
> the bracket locking nuts, and a crank extractor for, er,
> extracting the cranks.
>
> d.
>
It's *far* more likely to be a crank problem. You'll just
need a crank bolt spanner (14mm recessed socket, usually) or
allen key (8mm usually) if this is the case. It should just
need to be tightened. Sometimes removing the cranks and
turning through 90 degrees also helps, but for this you'll
need a crank extractor. Take the bike to a good shop and ask
them which tools you need if you're not sure - if you get
someone helpful they might also help with your prognosis.

---
Outgoing mail is certified Virus Free. Checked by AVG anti-
virus system (http://www.grisoft.com). Version: 6.0.644 /
Virus Database: 412 - Release Date: 26/03/2004

 

[John Latter]

On Sun, 28 Mar 2004 16:11:04 +0100, John Latter <[email protected]>
wrote:

>Hi,
>
>I brought an Argos 'Boss Reflex' cycle for £129 in November
>which I exchanged (for the same model) two weeks ago
>because of bottom bracket bearing problems.
>
>Now the new bike is playing up! First I got side-to-side
>play from the cranks which a friendly Halfords engineer
>sorted out for me (apparently the bb mechanism consists of
>component parts which is the old way of doing things).
>
>The latest problem (which I hope you can help me with) is a
>distinct 'clunking' sound which happens in all gears and is
>mostly associated with any pressure on the right hand pedal
>(where the three chain thingies are) when it is at the top
>of its 'orbit'.
>
>Er, I'm not very knowledgeable about bikes, nor very good
>at describing symptoms, but I hope the foregoing may make
>some sense to somebody!
>
>I also hope its easy for someone like me to sort out
>

Thankyou to everyone who replied & for the info!

I'm going to try & see if Argos will allow me to swap it for
a more expensive model (seeing as this is the second one of
this type I've had & this one is only 2 weeks old) - and pay
the difference of course


An engineer at Halfords did tighten everything up around the
bottom bracket (including the crank bolts) last monday. If
Argos don't allow an upgrade then I guess I'll have to pay
for a shimano thingy (£15 + £8 labour). Seems a bit much
though considering how new the bike is!

Thanks again,

--

John Latter

Model of an Internal Evolutionary Mechanism (based on an
extension to homeostasis) linking Stationary-Phase Mutations
to the Baldwin Effect.
http://members.aol.com/jorolat/TEM.html

'Where Darwin meets Lamarck?' Discussion Egroup
http://groups.yahoo.com/group/evomech

 

[Tony Raven]

John Latter wrote:

>
> An engineer at Halfords did tighten everything up around
> the bottom bracket (including the crank bolts) last
> monday. If Argos don't allow an upgrade then I guess I'll
> have to pay for a shimano thingy (£15 + £8 labour). Seems
> a bit much though considering how new the bike is!
>

Its likely the next one up will also have the same bottom
bracket. Its a place that manufacturers can save money
without it being immediately obvious to the buyer. If you
like the bike generally I would suggest changing the bottom
bracket. The type you have is notorious to keep set up while
the Shimano is a sealed unit that works until it stops
working then you throw it away and put in another. If you
talk nicely to the shop you have a good chance of having the
labour waived.

Tony

 

[Tony Raven]

Just zis Guy, you know? wrote:
>
> The UN72 might be, but I wore out a UN52 in under a year.

I've found them pretty reliable - it must be that strange
position you have yours in up front rather than in its
proper place down below ;-)

Tony

 

[Just Zis Guy]

On Sun, 28 Mar 2004 19:08:27 +0100, "Tony Raven"
<[email protected]> wrote in message
<[email protected]>:

>> The UN72 might be, but I wore out a UN52 in under a year.

>I've found them pretty reliable - it must be that strange
>position you have yours in up front rather than in its
>proper place down below ;-)

'Twas on the wedgie, tho. The 'bent has a UN72 as standard.

--
Guy
===
May contain traces of irony. Contents liable to settle after
posting. http://www.chapmancentral.co.uk

88% of helmet statistics are made up, 65% of them at
Washington University