R. Derailer idler pullies

I spent some time cleaned and lubed a 105 rear derailer that I'll
probably use in the new(old) bike. I noticed that the idler pulleys
are extremely loose and wonder whether they should be replaced. The
lower one is probably not too important but the upper pulley is what
derails the chain and I would think that if it wiggled from side to
side it would effect shifting.

Comments ?
--

Cheers,

John B.

On 11/20/2015 5:06 AM, John B. wrote:


I spent some time cleaned and lubed a 105 rear derailer that I'll
probably use in the new(old) bike. I noticed that the idler pulleys
are extremely loose and wonder whether they should be replaced. The
lower one is probably not too important but the upper pulley is what
derails the chain and I would think that if it wiggled from side to
side it would effect shifting.

Comments ?
--

Cheers,

John B.


It's not a bug, it's a feature.
Shimano calls the top roller design 'centeron pulley'. It's
supposed to slide laterally so as to center under the
sprocket without rocking. Various materials were used across
years and models, the most expensive of which have ceramic
liners over a ceramic bush.

It's a contributing part of an index system, which is to
say that several features combine for snappy index shifting
not just the shifter itself.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Friday, November 20, 2015 at 2:31:03 PM UTC+1, AMuzi wrote:
On 11/20/2015 5:06 AM, John B. wrote:


I spent some time cleaned and lubed a 105 rear derailer that I'll
probably use in the new(old) bike. I noticed that the idler pulleys
are extremely loose and wonder whether they should be replaced. The
lower one is probably not too important but the upper pulley is what
derails the chain and I would think that if it wiggled from side to
side it would effect shifting.

Comments ?
--

Cheers,

John B.


It's not a bug, it's a feature.
Shimano calls the top roller design 'centeron pulley'. It's
supposed to slide laterally so as to center under the
sprocket without rocking. Various materials were used across
years and models, the most expensive of which have ceramic
liners over a ceramic bush.

It's a contributing part of an index system, which is to
say that several features combine for snappy index shifting
not just the shifter itself.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

Lateral movement it's OK. It makes the adjusting less critical. I prever pulley that doesn't have lateral play though. If the pulley shows rotational movement along X axes (X is the traveling direction) because of a worn pulley bearing you get sloppy shifting because of the hysteresis. Time to replace the pulleys for me.

Lou

On Fri, 20 Nov 2015 07:30:57 -0600, AMuzi wrote:

On 11/20/2015 5:06 AM, John B. wrote:


I spent some time cleaned and lubed a 105 rear derailer that I'll
probably use in the new(old) bike. I noticed that the idler pulleys
are extremely loose and wonder whether they should be replaced. The
lower one is probably not too important but the upper pulley is what
derails the chain and I would think that if it wiggled from side to
side it would effect shifting.

Comments ?
--

Cheers,

John B.


It's not a bug, it's a feature.
Shimano calls the top roller design 'centeron pulley'. It's
supposed to slide laterally so as to center under the
sprocket without rocking. Various materials were used across
years and models, the most expensive of which have ceramic
liners over a ceramic bush.


I'll look at it again but my initial impression was that the bushing
was work and it wiggled, i.e. tilted back and forth.

It's a contributing part of an index system, which is to
say that several features combine for snappy index shifting
not just the shifter itself.
--

Cheers,

John B.

On 20/11/15 21:06, John B. wrote:


I spent some time cleaned and lubed a 105 rear derailer that I'll
probably use in the new(old) bike. I noticed that the idler pulleys
are extremely loose and wonder whether they should be replaced. The
lower one is probably not too important but the upper pulley is what
derails the chain and I would think that if it wiggled from side to
side it would effect shifting.

Comments ?

Yes.

--
JS

On Friday, November 20, 2015 at 4:06:35 AM UTC-7, John B. wrote:
I spent some time cleaned and lubed a 105 rear derailer that I'll
probably use in the new(old) bike. I noticed that the idler pulleys
are extremely loose and wonder whether they should be replaced. The
lower one is probably not too important but the upper pulley is what
derails the chain and I would think that if it wiggled from side to
side it would effect shifting.

Comments ?
--

Cheers,

John B.

SYNTHETIC BOAT TRAILER BEARING GREASE IS PERFECT FOR IDLERS

buy where you are ?

On 11/20/2015 6:44 PM, John B. wrote:
On Fri, 20 Nov 2015 07:30:57 -0600, AMuzi wrote:

On 11/20/2015 5:06 AM, John B. wrote:


I spent some time cleaned and lubed a 105 rear derailer that I'll
probably use in the new(old) bike. I noticed that the idler pulleys
are extremely loose and wonder whether they should be replaced. The
lower one is probably not too important but the upper pulley is what
derails the chain and I would think that if it wiggled from side to
side it would effect shifting.

Comments ?
--

Cheers,

John B.


It's not a bug, it's a feature.
Shimano calls the top roller design 'centeron pulley'. It's
supposed to slide laterally so as to center under the
sprocket without rocking. Various materials were used across
years and models, the most expensive of which have ceramic
liners over a ceramic bush.


I'll look at it again but my initial impression was that the bushing
was work and it wiggled, i.e. tilted back and forth.

It's a contributing part of an index system, which is to
say that several features combine for snappy index shifting
not just the shifter itself.
--

Cheers,

John B.


in that case, it's worn out. They are cheap and myriad
aftermarket products exists besides a host of Shimano models.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Sat, 21 Nov 2015 09:04:36 -0600, AMuzi wrote:

On 11/20/2015 6:44 PM, John B. wrote:
On Fri, 20 Nov 2015 07:30:57 -0600, AMuzi wrote:

On 11/20/2015 5:06 AM, John B. wrote:


I spent some time cleaned and lubed a 105 rear derailer that I'll
probably use in the new(old) bike. I noticed that the idler pulleys
are extremely loose and wonder whether they should be replaced. The
lower one is probably not too important but the upper pulley is what
derails the chain and I would think that if it wiggled from side to
side it would effect shifting.

Comments ?
--

Cheers,

John B.


It's not a bug, it's a feature.
Shimano calls the top roller design 'centeron pulley'. It's
supposed to slide laterally so as to center under the
sprocket without rocking. Various materials were used across
years and models, the most expensive of which have ceramic
liners over a ceramic bush.


I'll look at it again but my initial impression was that the bushing
was work and it wiggled, i.e. tilted back and forth.

It's a contributing part of an index system, which is to
say that several features combine for snappy index shifting
not just the shifter itself.
--

Cheers,

John B.


in that case, it's worn out. They are cheap and myriad
aftermarket products exists besides a host of Shimano models.

That's what I figured and will replace it :-)
--

Cheers,

John B.