Loud noise from single speed chain
dimitris_...@yahoo.com
Hello there,
I just installed a KMC Z510RB 1/8" chain on my bicycle (internal gear
with Shimano Nexus crankset FC-NX 75). The chain makes tremendous
noise when each link disengages (for some reason it snaps) the front
cog (38-tooth). The crankset is new as well and the chain line seems
alright.
Any idea what may be the problem? Would a 3/32" chain make a
difference?
Thank you in advance
Dimitris
Tºm Shermªn™ °_°
Check to make sure the chainring is both flat and parallel to the rear cog.
Also take a look at this article: <http://www.fagan.co.za/Bikes/Csuck/>.
--
Tºm Shermªn - 42.435731,-83.985007
I am a vehicular cyclist.
thirty-six
Too tight. You need some play in the chain in all positions.
thirty-six
I'll rephrase that, the chain is tight, any tightness is "too tight".
landotter
Check your chain tension throughout the rotation. That's a heavy duty
chain, it's gonna make a little noise even if the tension is correct.
Also check chain line. If the noise bothers you, an inexpensive 3/23"
chain will likely be quieter. Some chains are louder than others. I
find a SRAM PC-1 on 3/32 cogs is almost unbearably loud, while a KMC Z
is acceptable. YMMV
(PeteCresswell)
>The crankset is new as well and the chain line seems
>alright.
>
>Any idea what may be the problem?
When it happens to me, it is bc I've stomped on the cranks too
hard and the rear wheel has shifted out of alignment enough to
make the chain tight.
--
PeteCresswell
Lou Holtman
The loudest chain I ever used on my singlespeed. After one ride I
ditched it. Never bothered to find out why it was so ridiculous loud.
Use 8 or 9 speed derailleur chains now and they are all quit.
Lou
Andre Jute
Er, why did you choose this off-road chain; any good 3/32nd inch chain
would be quieter.
The outstanding, purpose designed KMC chain for internal gearboxes on
comfort and touring bikes is the X8, available in two finishes and
prices, -93 plain and -99 nickel plated. I use it myself on all my HGB
bikes (Nexus, Cyber Nexus and Rohloff) and it is a superb, quiet,
longlasting chain. Its only downside is that it is a bit pricey.
Andre Jute
http://members.lycos.co.uk/fiultra/Andre%20Jute's%20Utopia%20Kranich.pdf
John Henderson
> I just installed a KMC Z510RB 1/8" chain on my bicycle (internal gear
> with Shimano Nexus crankset FC-NX 75). The chain makes tremendous
> noise when each link disengages (for some reason it snaps) the front
> cog (38-tooth). The crankset is new as well and the chain line seems
> alright.
>
> Any idea what may be the problem? Would a 3/32" chain make a
> difference?
If this is happening only under load, you may be experiencing
the single-speed version of chain skip.
With a derailleur (or other chain tensioner) fitted, a new chain
on a worn rear sprocket occasionally rides up on the top of
sprocket teeth until it advances one complete tooth and jumps
back into engagement in the new position.
A single-speed with correct chain tension simply can't skip. So
it runs rough and noisily instead.
Try replacing the rear sprocket.
John
AMuzi
Is the chain too tight? Ensure there's half an inch of play
at the tight spot:
http://www.yellowjersey.org/chainchk.html
--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971
dimitris_...@yahoo.com
Thank you all for your comments. To make a couple points clearer:
- The noise is coming from the chainring and not the rear cog. When
each chain link disengages the chainring (at the lowest point of the
ring) it "snaps" outwards.
- The chain ring is brand new. The rear cog is old however it does not
seem to affect the situation.
- There is enough slack in the chain
- The chainline seems ok (no more than 2mm off), and it is definitely
much better than any multi-speed bike I have owned in the past. I
thought that the chainline tolerances where much larger. Please
correct me if I am wrong.
- I got the 1/8" chain because I had read that they are stronger and
more reliable. Now I can see that the chain "floats" left and right on
the 3/32" chainring. This could create the problem.
I guess the easier thing I could do is to replace the chain with a
3/32" one and see what happens. If this does not work, then should I
try a longer bottom bracket to fix the chainline?
Many thanks again for your help
Dimitris
thirty-six
You shouldn't normally use a 1/8" chain unless at least one of the
sprockets is also 1/8"
>
> I guess the easier thing I could do is to replace the chain with a
> 3/32" one and see what happens. If this does not work, then should I
> try a longer bottom bracket to fix the chainline?
Try oiling the chain. 2mm deviation from true is nothing. It is
certainly possible that the chain is temporarily stiff due to the
heavy grease installed by the manufacturer, you could bear with it for
a while until the chain loosens up.
John Henderson
> - The noise is coming from the chainring and not the rear cog. When
> each chain link disengages the chainring (at the lowest point of the
> ring) it "snaps" outwards.
The important thing is whether it's happening only under load.
If your noise happens without a lot of pressure being applied to
the pedals, it's not caused by a worn rear sprocket.
A worn rear sprocket will want to skip under load. If it's
prevented from doing so by fixed chain adjustment, the whole
chain will regularly jerk forwards and backwards as it's forced
to track and accommodate the bad tooth profile on the rear
sprocket.
John
dimitris_...@yahoo.com
John,
The noise happens only under load (even the slightest). When
backpedaling or rotating forward while coasting then there is no
noise. Do you think I should be looking at the rear cog?
Thanks
Dimitris
thirty-six
Check, not only you rchainline (top run) but also the bottom run and
th echainwheel alignment vertically( I mean with th eseatube). A worn
rear sprocket could certainly sound and appear like the problem
occcurs at the leaving of the chain from the crankset
John Henderson
> The noise happens only under load (even the slightest). When
> backpedaling or rotating forward while coasting then there is no
> noise. Do you think I should be looking at the rear cog?
It'd be replacing the rear cog. They wear out just like they do
on derailleur systems, and the result is noise and rough running.
Like "thirty-six" says, the problem will start on the lower run.
That's because a new chain will not be able to feed smoothly onto
the cog at the bottom. Load will move the unstretched chain too
far forwards (into wear pockets at the top of the cog) for the
links to slip past the unworn part of the tooth profile (at the
bottom where the chain feeds onto the cog).
In order to mesh, the chain then has to move backwards
momentarily against the driving load.
On a derailleur system, the chain doesn't have to move back.
Rather it rides up on top of the cog teeth (starting at the
bottom), resulting in skipping.
John
dimitris_...@yahoo.com
I replaced the rear cog and .... problem solved! Pedaling is now silky
smooth. It was amazing how worn the old cog was. Finding the right
part was not that easy (few LBSs stock them) however it was cheap and
the replacement was straightforward (with some help from youtube). It
also gave me the chance to relube and tighten the hub.
Thanks again for your help
Dimitris
On Jan 21, 3:58 am, John Henderson <jhenRemoveT...@talk21.com> wrote: