A Cycling & bikes forum. CycleBanter.com

Go Back   Home » CycleBanter.com forum » rec.bicycles » Techniques
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

new chain, slack



 
 
Thread Tools Display Modes
  #21  
Old December 20th 17, 05:28 PM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 6,335
Default new chain, slack


goo.gl/kXV7F5
Ads
  #22  
Old December 23rd 17, 12:53 AM posted to rec.bicycles.tech
Emanuel Berg[_2_]
external usenet poster
 
Posts: 517
Default new chain, slack

Frank Krygowski wrote:

Chain wear happens inside the chain's pivots.
The wear is on the pins, the rollers and any
surface between them.

The wear happens when the pivot is under
tension and the two links connected by that
pivot are either bending or straightening.


OK...? Do you have a picture that illustrates
this or at least identifies the parts refered
to? I have this

http://user.it.uu.se/~embe8573/bike/...erminology.jpg

but "pivot" isn't mentioned...

And how long should you be able to go before
the slack exposes you a fraud mechanic
and/or the owner of crooked gear?


For derailleur bikes, many people recommend
replacing a chain when it's worn (or
"stretched") so it's one half percent longer
than when new. (This is most easily measured
with a ruler marked in inches. Do you have
one of those?)


Eheh... what's next, you going to ask Picasso
if he has a brush? Of course I have folding
rule, ruler, measuring tape, and calipers in
inches as well as cm.

But you have to remove the chain to do this,
right? So it is not so fast after all.
Even less so with a chain guard which is very
common on these bikes.

The method I use is: see if the chain is slack.
If it is, move the wheel back. If it can't be
done, get a new chain. Some people remove links
but chains are so cheap anyway.

--
underground experts united
http://user.it.uu.se/~embe8573
  #23  
Old December 23rd 17, 12:57 AM posted to rec.bicycles.tech
Emanuel Berg[_2_]
external usenet poster
 
Posts: 517
Default new chain, slack

James wrote:

Is it possible the rear axle nuts were simply
not done up quite tight enough and the axle
slipped forward in the drop out slots?


Well, yeah, maybe! Shimano says, somewhere (?),
dome nuts or wheel axle nuts should be
28-32 Nm.

I have my torque wrench permanently at 30 Nm as
this is the only application I found so far,
sadly

--
underground experts united
http://user.it.uu.se/~embe8573
  #24  
Old December 23rd 17, 01:01 AM posted to rec.bicycles.tech
Emanuel Berg[_2_]
external usenet poster
 
Posts: 517
Default new chain, slack

Frank Krygowski wrote:

This has a couple possible implications.
Here's one: sprockets (especially chainrings
on less expensive bikes) are seldom perfectly
round. Usually you can notice the change in
tension (i.e. change in visible slack) as you
turn the cranks with the bike on a stand.
I suppose it's possible that the first
estimate of chain "tightness" happened with
the chain on a high spot, the next one on
a low spot.


That's true! What spot should you choose, then?

I always put the crank vertically, the one
where I can pull the most.

I haven't thought of the possibility of
overstretching at the other end. But you have
to pull really tight for that to happen, right?

--
underground experts united
http://user.it.uu.se/~embe8573
  #25  
Old December 23rd 17, 05:56 AM posted to rec.bicycles.tech
Frank Krygowski[_2_]
external usenet poster
 
Posts: 6,966
Default new chain, slack

On Friday, December 22, 2017 at 6:53:15 PM UTC-5, Emanuel Berg wrote:
Frank Krygowski wrote:

Chain wear happens inside the chain's pivots.
The wear is on the pins, the rollers and any
surface between them.

The wear happens when the pivot is under
tension and the two links connected by that
pivot are either bending or straightening.


OK...? Do you have a picture that illustrates
this or at least identifies the parts refered
to? I have this

http://user.it.uu.se/~embe8573/bike/...erminology.jpg

but "pivot" isn't mentioned...


By pivot, I meant the pin and the plates attached to it. The part that acts as a
hinge. The point is, to get wear in the chain, you need pressure on the surfaces
in contact, and you need relative motion between those surfaces.

And how long should you be able to go before
the slack exposes you a fraud mechanic
and/or the owner of crooked gear?


For derailleur bikes, many people recommend
replacing a chain when it's worn (or
"stretched") so it's one half percent longer
than when new. (This is most easily measured
with a ruler marked in inches. Do you have
one of those?)


Eheh... what's next, you going to ask Picasso
if he has a brush? Of course I have folding
rule, ruler, measuring tape, and calipers in
inches as well as cm.


Well, I didn't know. In the U.S. it's not unheard of for people to have no
ruler that measures in centimeters.

But you have to remove the chain to do this,
right?


Not usually. It's most easily done with the chain on the bike. Just use the
cranks to apply a little tension.

So it is not so fast after all.
Even less so with a chain guard which is very
common on these bikes.


If the chainguard totally encloses the chain, then yes, it's more trouble. OTOH,
if you have a totally enclosed chain, it will probably last as long as the bike.

- Frank Krygowski

  #26  
Old December 23rd 17, 06:01 AM posted to rec.bicycles.tech
Frank Krygowski[_2_]
external usenet poster
 
Posts: 6,966
Default new chain, slack

On Friday, December 22, 2017 at 7:01:07 PM UTC-5, Emanuel Berg wrote:
Frank Krygowski wrote:

This has a couple possible implications.
Here's one: sprockets (especially chainrings
on less expensive bikes) are seldom perfectly
round. Usually you can notice the change in
tension (i.e. change in visible slack) as you
turn the cranks with the bike on a stand.
I suppose it's possible that the first
estimate of chain "tightness" happened with
the chain on a high spot, the next one on
a low spot.


That's true! What spot should you choose, then?

I always put the crank vertically, the one
where I can pull the most.


I set the cranks in the position where the chain is tightest, and make sure
there's at least a tiny amount of slack there.


I haven't thought of the possibility of
overstretching at the other end. But you have
to pull really tight for that to happen, right?


You won't literally stretch the chain no matter what you do. I suppose you
might cause extra wear, though, if you had it excessively tight.

- Frank Krygowski

  #27  
Old December 23rd 17, 02:59 PM posted to rec.bicycles.tech
AMuzi
external usenet poster
 
Posts: 9,126
Default new chain, slack

On 12/22/2017 11:01 PM, Frank Krygowski wrote:
On Friday, December 22, 2017 at 7:01:07 PM UTC-5, Emanuel Berg wrote:
Frank Krygowski wrote:

This has a couple possible implications.
Here's one: sprockets (especially chainrings
on less expensive bikes) are seldom perfectly
round. Usually you can notice the change in
tension (i.e. change in visible slack) as you
turn the cranks with the bike on a stand.
I suppose it's possible that the first
estimate of chain "tightness" happened with
the chain on a high spot, the next one on
a low spot.


That's true! What spot should you choose, then?

I always put the crank vertically, the one
where I can pull the most.


I set the cranks in the position where the chain is tightest, and make sure
there's at least a tiny amount of slack there.


I haven't thought of the possibility of
overstretching at the other end. But you have
to pull really tight for that to happen, right?


You won't literally stretch the chain no matter what you do. I suppose you
might cause extra wear, though, if you had it excessively tight.

- Frank Krygowski


Overly tight chain will destroy hub and crank bearings
before significant chain wear.

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


  #28  
Old December 23rd 17, 04:00 PM posted to rec.bicycles.tech
Sir Ridesalot
external usenet poster
 
Posts: 3,599
Default new chain, slack

On Saturday, December 23, 2017 at 8:59:06 AM UTC-5, AMuzi wrote:
On 12/22/2017 11:01 PM, Frank Krygowski wrote:
On Friday, December 22, 2017 at 7:01:07 PM UTC-5, Emanuel Berg wrote:
Frank Krygowski wrote:

This has a couple possible implications.
Here's one: sprockets (especially chainrings
on less expensive bikes) are seldom perfectly
round. Usually you can notice the change in
tension (i.e. change in visible slack) as you
turn the cranks with the bike on a stand.
I suppose it's possible that the first
estimate of chain "tightness" happened with
the chain on a high spot, the next one on
a low spot.

That's true! What spot should you choose, then?

I always put the crank vertically, the one
where I can pull the most.


I set the cranks in the position where the chain is tightest, and make sure
there's at least a tiny amount of slack there.


I haven't thought of the possibility of
overstretching at the other end. But you have
to pull really tight for that to happen, right?


You won't literally stretch the chain no matter what you do. I suppose you
might cause extra wear, though, if you had it excessively tight.

- Frank Krygowski


Overly tight chain will destroy hub and crank bearings
before significant chain wear.

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


I seem to recall manuals for 3-speed or coaster brake bicycles stating that cthere should be 1/8th of an inch slack in the chain at its tightest point. That was from the 1970s or thereabouts. Does that still hold true?

CHeers
  #29  
Old December 23rd 17, 04:28 PM posted to rec.bicycles.tech
AMuzi
external usenet poster
 
Posts: 9,126
Default new chain, slack

On 12/23/2017 9:00 AM, Sir Ridesalot wrote:
On Saturday, December 23, 2017 at 8:59:06 AM UTC-5, AMuzi wrote:
On 12/22/2017 11:01 PM, Frank Krygowski wrote:
On Friday, December 22, 2017 at 7:01:07 PM UTC-5, Emanuel Berg wrote:
Frank Krygowski wrote:

This has a couple possible implications.
Here's one: sprockets (especially chainrings
on less expensive bikes) are seldom perfectly
round. Usually you can notice the change in
tension (i.e. change in visible slack) as you
turn the cranks with the bike on a stand.
I suppose it's possible that the first
estimate of chain "tightness" happened with
the chain on a high spot, the next one on
a low spot.

That's true! What spot should you choose, then?

I always put the crank vertically, the one
where I can pull the most.

I set the cranks in the position where the chain is tightest, and make sure
there's at least a tiny amount of slack there.


I haven't thought of the possibility of
overstretching at the other end. But you have
to pull really tight for that to happen, right?

You won't literally stretch the chain no matter what you do. I suppose you
might cause extra wear, though, if you had it excessively tight.


Overly tight chain will destroy hub and crank bearings
before significant chain wear.



I seem to recall manuals for 3-speed or coaster brake bicycles stating that cthere should be 1/8th of an inch slack in the chain at its tightest point. That was from the 1970s or thereabouts. Does that still hold true?



At minimum:
http://www.yellowjersey.org/chainchk.html

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


  #30  
Old December 23rd 17, 09:28 PM posted to rec.bicycles.tech
Emanuel Berg[_2_]
external usenet poster
 
Posts: 517
Default new chain, slack

Frank Krygowski wrote:

By pivot, I meant the pin and the plates
attached to it. The part that acts as
a hinge. The point is, to get wear in the
chain, you need pressure on the surfaces in
contact, and you need relative motion between
those surfaces.


OK, but is there a reason why you bring this up
in such detail? Because isn't this just what
one would expect to happen from pulling
something in a chain?

Well, I didn't know. In the U.S. it's not
unheard of for people to have no ruler that
measures in centimeters.


Altho the metric system is completely prevalent
here in general, it seems almost all specific
fields has some or many conventions using the
old English system. Not just bikes: boxing
gloves, downpipes, drums...

--
underground experts united
http://user.it.uu.se/~embe8573
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
OBree uses a slack chain someone Techniques 68 September 16th 09 02:19 AM
OBree uses a slack chain Fred Fredburger[_6_] Racing 0 September 15th 09 08:09 PM
Advice On Slack In Kh-schlumpf? Paulo Unicycling 4 May 18th 08 07:57 PM
Chain side slack Pat and Bob Chambers UK 1 September 8th 05 11:37 AM
Chain Side Slack Pat and Bob Chambers Australia 1 September 8th 05 09:23 AM


All times are GMT +1. The time now is 10:32 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright 2004-2018 CycleBanter.com.
The comments are property of their posters.