chainwheel wear

Do you determine the status of a chainwheel
by inspection?

Should you do this now and then, or is it safe
to wait for the rear to make unfamiliar noises
and then examine it further?

Is some pointyness to the teeth acceptable?
How much?

And how is it that tho the chain pulls forward,
sometimes there seem to be as much wear
*sideways* on the tooth?

Do they come in different materials which are
better/worse in this respect?

/The hairdresser

--
underground experts united .... http://user.it.uu.se/~embe8573
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On 19/05/2016 1:45 AM, Emanuel Berg wrote:
Do you determine the status of a chainwheel
by inspection?

Should you do this now and then, or is it safe
to wait for the rear to make unfamiliar noises
and then examine it further?

Is some pointyness to the teeth acceptable?
How much?

And how is it that tho the chain pulls forward,
sometimes there seem to be as much wear
*sideways* on the tooth?

Do they come in different materials which are
better/worse in this respect?

/The hairdresser


You can try to determine wear by the "sharking" or flattening of the
teeth but I think it's difficult to know when it's time to replace it.
The sure way to know is when it slips. But a stretched chain can work
with a worn cassette.

I usually check my chain which is easier and replace that as needed.
Usually once you replace the chain, the worn cassette will slip. You
can test this by engaging the brake and pushing down on the pedal.

http://www.artscyclery.com/learningc...settewear.html

On 5/19/2016 12:45 AM, Emanuel Berg wrote:
Do you determine the status of a chainwheel
by inspection?

Should you do this now and then, or is it safe
to wait for the rear to make unfamiliar noises
and then examine it further?

Is some pointyness to the teeth acceptable?
How much?

And how is it that tho the chain pulls forward,
sometimes there seem to be as much wear
*sideways* on the tooth?

Do they come in different materials which are
better/worse in this respect?

/The hairdresser

Please see section #8d.2 he
http://www.faqs.org/faqs/bicycles-faq/part3/

image:
http://www.yellowjersey.org/photosfromthepast/WORN.JPG


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

On 5/18/2016 10:45 PM, Emanuel Berg wrote:
Do you determine the status of a chainwheel
by inspection?

Should you do this now and then, or is it safe
to wait for the rear to make unfamiliar noises
and then examine it further?

Always a good idea to check now and then, but you have a much larger
margin of error with worn chainrings than with worn rear cogs, due to
the larger diameter. (May not apply if you have a 26T ring you use
/all/ the time, but that's hard to imagine.)

Be sure to read the faq Andrew Muzi linked to, to review the standard
chain/cog wear concerns and maintenance.

Is some pointyness to the teeth acceptable?
How much?

You can get away with a /lot/, certainly if the ring is large. Does
your shifting degrade in front? Might be time for a new ring. On our
tandem, the big ring teeth got very very pointy and sharp/narrowed
(maybe "dangerously" so - at least it looked scary sharp), still worked
fine for us.

And how is it that tho the chain pulls forward,
sometimes there seem to be as much wear
*sideways* on the tooth?

I'm pretty sure that's from cross-chaining - if you mean the narrowing
of the teeth into sharp "blades." Avoid outside ring / inside cog and
similar combinations when possible.

Do they come in different materials which are
better/worse in this respect?

Yes. Not sure if there is as much variation today as years ago; Campy
/was/, and maybe still is, the standard for long-lived rings. TA had a
rep of very soft rings. So many rings are proprietary today, with many
cranks you have to tolerate the rings that come with it. With standard
bolt circles (e.g. 110) I'm sure you can find a wide variety. For tiny
rings (26T), steel is a good choice.

Mark J.

"Mark J." writes:

Be sure to read the faq Andrew Muzi linked
to, to review the standard chain/cog wear
concerns and maintenance.

Yes, definitely.

--
underground experts united .... http://user.it.uu.se/~embe8573
Emacs Gnus Blogomatic ......... http://user.it.uu.se/~embe8573/blogomatic
- so far: 34 Blogomatic articles -

On 5/19/2016 5:54 PM, Mark J. wrote:
On 5/18/2016 10:45 PM, Emanuel Berg wrote:
Do you determine the status of a chainwheel
by inspection?

Should you do this now and then, or is it safe
to wait for the rear to make unfamiliar noises
and then examine it further?

Always a good idea to check now and then, but you have a much larger
margin of error with worn chainrings than with worn rear cogs, due to
the larger diameter. (May not apply if you have a 26T ring you use
/all/ the time, but that's hard to imagine.)

FWIW, I got to ride a friend's fat bike (mountain bike) about a week
ago. It had SRAM's 1x11 (?) transmission. I don't know how small that
front chainring was, but it was tiny.

I did wonder how long it would last.


Be sure to read the faq Andrew Muzi linked to, to review the standard
chain/cog wear concerns and maintenance.

Is some pointyness to the teeth acceptable?
How much?

You can get away with a /lot/, certainly if the ring is large. Does
your shifting degrade in front? Might be time for a new ring. On our
tandem, the big ring teeth got very very pointy and sharp/narrowed
(maybe "dangerously" so - at least it looked scary sharp), still worked
fine for us.

I strongly suspect Emanuel is talking mostly about rear cogs, not front
chainrings.

But I did (only once) come across a bike whose front chainring was so
terribly worn that the chain skipped in the front any time I tried to
put serious force into the pedals. The chainring looked amazingly worn.
I don't think it would have passed even Ian's visual inspection.

--
- Frank Krygowski

Frank Krygowski
writes:

I strongly suspect Emanuel is talking mostly
about rear cogs, not front chainrings.

Yes

--
underground experts united .... http://user.it.uu.se/~embe8573
Emacs Gnus Blogomatic ......... http://user.it.uu.se/~embe8573/blogomatic
- so far: 36 Blogomatic articles -