Is this why my chain is slipping?

[Graham]

Maybe it is time to replace my chain again, but I am suspicious of the
derailleur. The chain slips badly when it is on the smallest rear
sprocket, but it doesn't slip if it is also on the larger front
sprocket. I think the derailleur mechanism is more limp than it used
to be, as though a spring has gone. Obviously the derailleur has to
put the greatest tension into the chain when it is on the smallest
sprocket, and that tension is lessened if the chain is also on the
larger front sprocket. Can anybody confirm or deny my suspicion? I
know the standard answer is "change your chain, and perhaps your
cassette as well". I do maybe 30 miles a week, in most weather
conditions, and last had the chain and cassette replaced 20 months
ago.

Graham
--
Graham Steel: [email protected]
Web: http://www.steelworks.org.uk

 

[Pete Biggs]

Graham wrote:
> Maybe it is time to replace my chain again, but I am suspicious of the
> derailleur. The chain slips badly when it is on the smallest rear
> sprocket, but it doesn't slip if it is also on the larger front
> sprocket. I think the derailleur mechanism is more limp than it used
> to be, as though a spring has gone. Obviously the derailleur has to
> put the greatest tension into the chain when it is on the smallest
> sprocket, and that tension is lessened if the chain is also on the
> larger front sprocket. Can anybody confirm or deny my suspicion? I
> know the standard answer is "change your chain, and perhaps your
> cassette as well". I do maybe 30 miles a week, in most weather
> conditions, and last had the chain and cassette replaced 20 months
> ago.

My guess is: derailleur is not broken or worn out but the chain is a bit
too long for the gear. It's also just about possible that the chain and
sprockets are worn out already (perhaps just the smallest sprocket).

Two or three rings upfront?

You shouldn't use the smallest chainring with the smallest rear sprocket
in any case. Excessive friction is generated from the crossed-over chain,
causing rapid wear. You'll get the same (or similar) ratio in other gear
anyway, and it'll be more efficient because of the larger sprockets. Same
goes for the largest ring with largest rear sprocket (although that's not
necessarily so inefficient).

If you want to try shortening the chain, make sure it's still long enough
for the big-big to work (just in case it's accidentally selected, at
least).
See <url:http://www.parktool.com/repair_help/FAQchainlength.shtml>

Also check all general derailleur and cable adjustments and the chain is
free from stiff links. (Any problems from these things might happen to be
showing up more in the top sprocket more than other gears).
See url:http://sheldonbrown.com/derailer-adjustment.html

~PB

 

[Pete Biggs]

> It's also just about possible that the
> chain and sprockets are worn out already (perhaps just the smallest
> sprocket).

That wouldn't explain why it doesn't skip from the largest chainring, but
you might not have actually pedalled so hard in top gear to test it (?)
(for all I know).

~PB

 

[Jack Ouzzi]

On Mon, 23 Aug 2004 22:01:25 +0100, "Pete Biggs"
<pblackcherry{remove_fruit}@biggs.tc> wrote:


>Two or three rings upfront?
>
>You shouldn't use the smallest chainring with the smallest rear sprocket
>in any case. Excessive friction is generated from the crossed-over chain,
>causing rapid wear. You'll get the same (or similar) ratio in other gear
>anyway,

Which begs the question, why do off the peg road bikes today (not
saying the original poster has a road bike) have up to 27 gears (9
block + triple ring) .............. all that extra weight, all those
same ratios ............

When I was touring I only ever used up to 8 gears, When I was racing I
probably ever only used 5 gears, When I was time trialling, only 2
gears .................... the success came with proper pedal cadance
......................... and hurting !!

Maybe its cool to have all these gears ...................

Bring back the 72" fixed ................... I use one, best training
tool ever !!

Mr Fit, Not Cool, but don't care .................

 

[Michael MacClancy]

On Tue, 24 Aug 2004 08:21:16 +0100, Jack Ouzzi wrote:


>
> Which begs the question, why do off the peg road bikes today (not
> saying the original poster has a road bike) have up to 27 gears (9
> block + triple ring) .............. all that extra weight, all those
> same ratios ............
>
> When I was touring I only ever used up to 8 gears, When I was racing I
> probably ever only used 5 gears, When I was time trialling, only 2
> gears .................... the success came with proper pedal cadance
> ........................ and hurting !!
>
> Maybe its cool to have all these gears ...................
>
> Bring back the 72" fixed ................... I use one, best training
> tool ever !!
>
> Mr Fit, Not Cool, but don't care .................

I bet you've still got an outside privy and no running water at home.

--
Michael MacClancy
Random putdown - "He loves nature in spite of what it did to him." -
Forrest Tucker
www.macclancy.demon.co.uk
www.macclancy.co.uk

 

[Mark South]

"Michael MacClancy" <[email protected]> wrote in message
news:[email protected]...
> On Tue, 24 Aug 2004 08:21:16 +0100, Jack Ouzzi wrote:
> >
> > Which begs the question, why do off the peg road bikes today (not
> > saying the original poster has a road bike) have up to 27 gears (9
> > block + triple ring) .............. all that extra weight, all those
> > same ratios ............
> >
> > When I was touring I only ever used up to 8 gears, When I was racing I
> > probably ever only used 5 gears, When I was time trialling, only 2
> > gears .................... the success came with proper pedal cadance
> > ........................ and hurting !!
> >
> > Maybe its cool to have all these gears ...................
> >
> > Bring back the 72" fixed ................... I use one, best training
> > tool ever !!
> >
> > Mr Fit, Not Cool, but don't care .................
>
> I bet you've still got an outside privy and no running water at home.

You need to have an Ordinary to lean against an outside privy.
--
Mark South, Super Genius: World Citizen, Net Denizen

 

[Pete Biggs]

Jack Ouzzi wrote:
> Which begs the question, why do off the peg road bikes today (not
> saying the original poster has a road bike) have up to 27 gears (9
> block + triple ring) .............. all that extra weight, all those
> same ratios ............

If "road bike" means racer-style bike then they don't actually. Most have
double chainsets.

But I like the 27 gears on mine. I couldn't care less that the three
ranges overlap (in fact that helps make them more practical). I have the
overall range I want, the (easily-selectable) differences between gears I
want*, and a middle ring that provides what I want for most of the time.
Sheer luxury ... except for all the gear changing ;-)

* Except I wouldn't mind an 18T between the 17 and 19. 30-speed next!

~PB

 

[Peter Clinch]

Pete Biggs wrote:
>
> But I like the 27 gears on mine. I couldn't care less that the three
> ranges overlap (in fact that helps make them more practical). I have the
> overall range I want, the (easily-selectable) differences between gears I
> want*, and a middle ring that provides what I want for most of the time.

That's about the size of it. The 27 on my tourer is about the same as
13 or 14 /actual/ gears, but I use that many and there isn't room for a
14 speed block back there...

I would use a Rohloff, but I can't rob a bank right now because it's
raining too much.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email protected] http://www.dundee.ac.uk/~pjclinch/

 

[Clive George]

"Peter Clinch" <[email protected]> wrote in message
news:[email protected]...
> Pete Biggs wrote:
> >
> > But I like the 27 gears on mine. I couldn't care less that the three
> > ranges overlap (in fact that helps make them more practical). I have
the
> > overall range I want, the (easily-selectable) differences between gears
I
> > want*, and a middle ring that provides what I want for most of the time.
>
> That's about the size of it. The 27 on my tourer is about the same as
> 13 or 14 /actual/ gears, but I use that many and there isn't room for a
> 14 speed block back there...
>
> I would use a Rohloff, but I can't rob a bank right now because it's
> raining too much.

I counted 19 actual gears on my 27sp setup - and the gaps on the rohloff are
too big for me. These things are not unrelated

cheers,
clive

 

[David Martin]

On 24/8/04 12:19 pm, in article [email protected], "Peter
Clinch" <[email protected]> wrote:

> I would use a Rohloff, but I can't rob a bank right now because it's
> raining too much.

Only on your side of the hill.. The sun is almost out here.

...d

 

[Graham]

Today the derailleur is hanging limp, and so is the chain. I have
answered my own question. Bike shop on Saturday ...

Graham


I wrote:

Maybe it is time to replace my chain again, but I am suspicious of the
derailleur. The chain slips badly when it is on the smallest rear
sprocket, but it doesn't slip if it is also on the larger front
sprocket. I think the derailleur mechanism is more limp than it used
to be, as though a spring has gone. Obviously the derailleur has to
put the greatest tension into the chain when it is on the smallest
sprocket, and that tension is lessened if the chain is also on the
larger front sprocket. Can anybody confirm or deny my suspicion? I
know the standard answer is "change your chain, and perhaps your
cassette as well". I do maybe 30 miles a week, in most weather
conditions, and last had the chain and cassette replaced 20 months
ago.

Graham
--
Graham Steel: [email protected]
Web: http://www.steelworks.org.uk

 

[Graham]

I have two rings up front. Not cycling with the chain on the two
smallest sprockets is news to me: I spend most of my time with the
chain on the smallest front sprocket and smallest rear sprocket. Feels
fine to me, except when the derailleur is on the way out. I normally
only ever switch to the larger front sprocket when the chain is on the
smallest rear sprocket, and it certainly feels like it is wearing if I
forget to switch back to the smaller front sprocket and have the chain
on the larger front sprocket and one of the larger rear sprockets.

Anyway, bike shop on Saturday ...

Graham

On Mon, 23 Aug 2004 22:01:25 +0100, "Pete Biggs"
<pblackcherry{remove_fruit}@biggs.tc> wrote:
(snipped)
>My guess is: derailleur is not broken or worn out but the chain is a bit
>too long for the gear. It's also just about possible that the chain and
>sprockets are worn out already (perhaps just the smallest sprocket).
>
>Two or three rings upfront?
>
>You shouldn't use the smallest chainring with the smallest rear sprocket
>in any case. Excessive friction is generated from the crossed-over chain,
>causing rapid wear. You'll get the same (or similar) ratio in other gear
>anyway, and it'll be more efficient because of the larger sprockets. Same
>goes for the largest ring with largest rear sprocket (although that's not
>necessarily so inefficient).
>

--
Graham Steel: [email protected]
Web: http://www.steelworks.org.uk