chain problems

[Rob Morley]

In article <[email protected]>, Ben C
[email protected] says...

> All the same, 1000 miles and 2 months? Something very odd going on.
>
Washing with solvent can fill the chain with grit while
removing/diluting lubricant if it's not done properly. It won't last
long in those circumstances.

 

[Rob Morley]

In article <[email protected]>, Adam Lea
[email protected] says...
>
> "Rob Morley" <[email protected]> wrote in message
> news:[email protected]...

> > What sort of chain, what sort of riding conditions, what lubricant did
> > you use?
>
> SRAM PC38 8 speed chain.

That's a pretty basic chain - I don't know if it's basic reasonable
quality or basic cheap'n'nasty, but I'm sure someone else here will tell
me.
>
> The vast majority of my riding is on country lanes. After any prolonged rain
> mud can be washed onto the road (or deposited by farm vehicles), so I guess
> this may contribute to wear and tear.

Fit a decent mud flap to the front mudguard to reduce the amount of crud
that finds its way onto the chain.
>
> I use Finish Line Cross Country Wet Lubricant and typically clean the chain
> and re-lubricate once a week.
>
Do you make sure the chain is really clean when you wash it, and make
sure it's really dry before you re-lube it? When I used to maintain my
bikes properly I would first wash the chain in solvent, and then swill
it around in a bowl of hot water and detergent, changing the water a
couple of times until I could see no more grit was being washed out,
then rinse and dry the chain on a radiator or in the oven to be sure it
was really properly dry. Proper chain lubes were expensive and exotic
in those days, but I did fine with multigrade.

 

[Tony Raven]

Rob Morley wrote on 18/02/2007 01:54 +0100:
>
> That's a pretty basic chain - I don't know if it's basic reasonable
> quality or basic cheap'n'nasty, but I'm sure someone else here will tell
> me.

Its fine as a chain and it will last as long as more expensive ones.
The economics are in favour IMO of using cheap chains and changing them
often rather than expensive chains and changing less frequently.

--
Tony

"...has many omissions and contains much that is apocryphal, or at least
wildly inaccurate..."
Douglas Adams; The Hitchhiker's Guide to the Galaxy

 

[Simon Brooke]

in message <[email protected]>, Adam Lea
('[email protected]') wrote:

>
> "Simon Brooke" <[email protected]> wrote in message
> news:[email protected]...
>> in message <[email protected]>, Adam Lea
>> ('[email protected]') wrote:
>>
>>>
>>> "Simon Brooke" <[email protected]> wrote in message
>>> news:[email protected]...
>>>> in message <[email protected]>, Adam Lea
>>>> ('[email protected]') wrote:
>>>>
>>>>> After having problems with a slipping chain I have discovered that
>>>>> the chain is stretched and no longer aligns with the teeth on the
>>>>> chainset. What has surprised me is the short time that this has taken
>>>>> to happen. I bought the bike new mid December and have done a little
>>>>> over a thousand miles on it up to now but this seems to be a very
>>>>> short time for a chain to wear out. This is despite cleaning it every
>>>>> week and applying the white spirit treatment every three weeks. How
>>>>> long should a good quality chain last and how can I prolong the life
>>>>> of my chain over and above regular cleaning?
>>>>
>>>> Something badly wrong there. What lubricant are you using and how do
>>>> you apply it? Also, is this a quality bike or an el-cheapo?
>>>>
>>>
>>> I use finish line wet lubricant which I apply a drop or two to each
>>> link, then add some to the rear cassette plus a bit on any other moving
>>> parts. I then spin the pedals and change through all the gears to
>>> spread the lubricant over the gears. I leave it for a while then wipe
>>> any excess off with a piece of kitchen towel.
>>>
>>> The bike is a Birdy tourer which, including extras, cost me 1,200 so
>>> not what you would class as a cheap bike.
>>
>> Then all I can say is I'm very surprised. You're following pretty much
>> the the regime I would, and I get far longer life out of my chains.
>
> I have bought a cheap replacement chain (£11 from LBS) and I will follow
> the advice given here about cleaning it (I have obviously been doing it
> wrong) and I shall see how long this one lasts. If this one wears quickly
> then I shall try a more expensive chain.

Don't clean it with solvent until it starts to squeak. The grease the
manufacturer gets in is better and more completely penetrated into the
chain than anything you can use. Dry rag only.

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

;; ... exposing the violence incoherent in the system...

 

[Simon Brooke]

in message <[email protected]>, Rob Morley
('[email protected]') wrote:

> In article <[email protected]>, Adam Lea
> [email protected] says...
>>
>> "Rob Morley" <[email protected]> wrote in message
>> news:[email protected]...
>
>> > What sort of chain, what sort of riding conditions, what lubricant did
>> > you use?
>>
>> SRAM PC38 8 speed chain.
>
> That's a pretty basic chain - I don't know if it's basic reasonable
> quality or basic cheap'n'nasty, but I'm sure someone else here will tell
> me.

All SRAM chains are reasonable quality. PC 38 is definitely OK.

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

;; MS Windows: A thirty-two bit extension ... to a sixteen bit
;; patch to an eight bit operating system originally coded for a
;; four bit microprocessor and sold by a two-bit company that
;; can't stand one bit of competition -- anonymous

 

[Chris Malcolm]

Tony Raven <[email protected]> wrote:

> Smaller wheeled bikes do tend to wear chains faster because the wheels
> turns more times

But the chain turns at the same speed...

> and the derailleur is closer to the road where the
> chain picks up more grit.

That's true.

--
Chris Malcolm [email protected] DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
[http://www.dai.ed.ac.uk/homes/cam/]

 

[Simon Brooke]

in message <[email protected]>, Chris Malcolm
('[email protected]') wrote:

> Tony Raven <[email protected]> wrote:
>
>> Smaller wheeled bikes do tend to wear chains faster because the wheels
>> turns more times
>
> But the chain turns at the same speed...

No. The cassette turns at the same speed as the wheel, so it turns more
times. If the front chainring is bigger, then the chain runs faster for a
given cadence. If the front chainring isn't bigger, then you going to have
to spin at some amazing cadence, and the chain runs faster.

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

'Victories are not solutions.'
;; John Hume, Northern Irish politician, on Radio Scotland 1/2/95
;; Nobel Peace Prize laureate 1998; few have deserved it so much

 

[Tony Raven]

Chris Malcolm wrote on 18/02/2007 11:01 +0100:
> Tony Raven <[email protected]> wrote:
>
>> Smaller wheeled bikes do tend to wear chains faster because the wheels
>> turns more times
>
> But the chain turns at the same speed...
>

No it doesn't if you think about it. Consider the case for simplicity
where you have the same tooth number cog on a small and large back
wheel. To cover the same distance the small back wheel will need to
turn more times. To turn it more times you will need a bigger front
chain wheel so every turn of that chain wheel, assuming constant cadence
for the speed, will pull more chain. Ah you say, but you use the same
size chain wheel and a smaller cog for the smaller wheel instead.
Except that the smallest cog size is limited by the available cassettes
which are designed for large wheel bikes (although the Capreo groupset
with its 9 tooth cog has helped a little but with other wear problems).
So in fact to get the right gear range most small wheel dérailleur
bikes use bigger chain wheels and therefore pull more chain per turn of
the pedals,


--
Tony

"...has many omissions and contains much that is apocryphal, or at least
wildly inaccurate..."
Douglas Adams; The Hitchhiker's Guide to the Galaxy

 

[Rob Morley]

In article <[email protected]>, Tony Raven
[email protected] says...
> Chris Malcolm wrote on 18/02/2007 11:01 +0100:
> > Tony Raven <[email protected]> wrote:
> >
> >> Smaller wheeled bikes do tend to wear chains faster because the wheels
> >> turns more times
> >
> > But the chain turns at the same speed...
> >
<snip>
> So in fact to get the right gear range most small wheel dérailleur
> bikes use bigger chain wheels and therefore pull more chain per turn of
> the pedals,
>
This means the chain is under less tension, which might be expected to
improve its life expectancy.

 

[Tony Raven]

Rob Morley wrote on 18/02/2007 12:14 +0100:
>
> This means the chain is under less tension, which might be expected to
> improve its life expectancy.

Tension occurs only on the top chain run where it has little effect as
most of the links are static relative to each other. The wear occurs
where the pins rotate in the bushes which occurs when it wraps itself
onto and off the cog and to a lesser extent the chainwheel.

--
Tony

"...has many omissions and contains much that is apocryphal, or at least
wildly inaccurate..."
Douglas Adams; The Hitchhiker's Guide to the Galaxy

 

[Rob Morley]

In article <[email protected]>, Tony Raven
[email protected] says...
> Rob Morley wrote on 18/02/2007 12:14 +0100:
> >
> > This means the chain is under less tension, which might be expected to
> > improve its life expectancy.
>
> Tension occurs only on the top chain run where it has little effect as
> most of the links are static relative to each other. The wear occurs
> where the pins rotate in the bushes which occurs when it wraps itself
> onto and off the cog and to a lesser extent the chainwheel.
>
>
Yebbut it's the tension in the chain that acts on the links that are
wrapped around the chainring and sprockets ...

 

[Tony Raven]

Rob Morley wrote on 18/02/2007 15:46 +0100:
> In article <[email protected]>, Tony Raven
> [email protected] says...
>> Rob Morley wrote on 18/02/2007 12:14 +0100:
>>> This means the chain is under less tension, which might be expected to
>>> improve its life expectancy.
>> Tension occurs only on the top chain run where it has little effect as
>> most of the links are static relative to each other. The wear occurs
>> where the pins rotate in the bushes which occurs when it wraps itself
>> onto and off the cog and to a lesser extent the chainwheel.
>>
>>
> Yebbut it's the tension in the chain that acts on the links that are
> wrapped around the chainring and sprockets ...

Nobbut the links wrapped around the chain ring and sprockets are static
i.e. there is no rotational movement between the pin and bush and it is
that rotational movement that causes the wear. Linear tension does
nothing of its own.

--
Tony

"...has many omissions and contains much that is apocryphal, or at least
wildly inaccurate..."
Douglas Adams; The Hitchhiker's Guide to the Galaxy

 

[Creature]

On Sun, 18 Feb 2007 11:16:44 +0000, Simon Brooke wrote:
> The cassette turns at the same speed as the wheel, so it turns more
> times.

*coughs*
Whether the cassette turns at the same speed as the wheel depends very
much on what part of the wheel we're talking about. For the most part, the
wheel is turning faster than the cassette.

Speed is, of course, distance/time. They are doing the same number of
revolutions, but the cassette may have a circumference of 5" where a wheel
is going to be closer to 26". The (outside edge of the) wheel is
travelling a further distance in the same time, and so therefore is moving
at a higher speed.

--
Alex Pounds (Creature) .~. http://www.alexpounds.com/
/V\ http://www.ethicsgirls.com/
// \\
"Variables won't; Constants aren't" /( )\
^`~'^

 

[Tony Raven]

Creature wrote on 18/02/2007 22:28 +0100:
> On Sun, 18 Feb 2007 11:16:44 +0000, Simon Brooke wrote:
>> The cassette turns at the same speed as the wheel, so it turns more
>> times.
>
> *coughs*
> Whether the cassette turns at the same speed as the wheel depends very
> much on what part of the wheel we're talking about. For the most part, the
> wheel is turning faster than the cassette.
>
> Speed is, of course, distance/time. They are doing the same number of
> revolutions, but the cassette may have a circumference of 5" where a wheel
> is going to be closer to 26". The (outside edge of the) wheel is
> travelling a further distance in the same time, and so therefore is moving
> at a higher speed.
>

You've not heard of rotational speed (measured e.g. in revolutions per
minute) then which the rest of us are talking about and is the same for
the wheel and the cassette except when freewheeling.

--
Tony

"...has many omissions and contains much that is apocryphal, or at least
wildly inaccurate..."
Douglas Adams; The Hitchhiker's Guide to the Galaxy

 

[Chris Malcolm]

Tony Raven <[email protected]> wrote:
> Chris Malcolm wrote on 18/02/2007 11:01 +0100:
>> Tony Raven <[email protected]> wrote:
>>
>>> Smaller wheeled bikes do tend to wear chains faster because the wheels
>>> turns more times
>>
>> But the chain turns at the same speed...

> No it doesn't if you think about it. Consider the case for simplicity
> where you have the same tooth number cog on a small and large back
> wheel. To cover the same distance the small back wheel will need to
> turn more times. To turn it more times you will need a bigger front
> chain wheel so every turn of that chain wheel, assuming constant cadence
> for the speed, will pull more chain. Ah you say, but you use the same
> size chain wheel and a smaller cog for the smaller wheel instead.
> Except that the smallest cog size is limited by the available cassettes
> which are designed for large wheel bikes (although the Capreo groupset
> with its 9 tooth cog has helped a little but with other wear problems).
> So in fact to get the right gear range most small wheel d?railleur
> bikes use bigger chain wheels and therefore pull more chain per turn of
> the pedals,

Ah, I see. I was assuming that general conservative bicycle
engineering would mean you'd have the same general size of chainwheel
in both cases.

--
Chris Malcolm [email protected] DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
[http://www.dai.ed.ac.uk/homes/cam/]

 

[Rob Morley]

In article <[email protected]>, Tony Raven
[email protected] says...
> Rob Morley wrote on 18/02/2007 15:46 +0100:
> > In article <[email protected]>, Tony Raven
> > [email protected] says...
> >> Rob Morley wrote on 18/02/2007 12:14 +0100:
> >>> This means the chain is under less tension, which might be expected to
> >>> improve its life expectancy.
> >> Tension occurs only on the top chain run where it has little effect as
> >> most of the links are static relative to each other. The wear occurs
> >> where the pins rotate in the bushes which occurs when it wraps itself
> >> onto and off the cog and to a lesser extent the chainwheel.
> >>
> >>
> > Yebbut it's the tension in the chain that acts on the links that are
> > wrapped around the chainring and sprockets ...
>
> Nobbut the links wrapped around the chain ring and sprockets are static
> i.e. there is no rotational movement between the pin and bush and it is
> that rotational movement that causes the wear. Linear tension does
> nothing of its own.
>
Yebbut if the chain wasn't pulled tight there would be very little force
acting on the rotating links to wear their bearing surfaces.