scored rollers on new chain

Quoted message said:

Hi

Having recently built a wheel for a fixed gear set up, am now onto the
next problem.

Parts ...

new SRAM PC58 chain 3/32",
new 16 tooth cog (supposed to be 3/32" - bought from the same place as
hub),
well-used 42 tooth chainring reversed, put on outer (still needs to be
1 - 2 mm further out).

The idea is that once I've briefly tested the thing out, I'll get a new
chainring.

Got the chain tension correct (I think) after reading various methods
(e.g. tight as it can be without binding).

Spinning the cranks, there's a regular, light, discrete rubbing coming
from around the cog. Didn't think that was too bad but I took the chain
off and there are two sets of scores/marks along every other roller.
i.e. on one roller the mark is near to lhs plate, next roller the mark
is near to rhs plate.

Any idea what's causing this grinding and how to solve it? It's made
quite a mess of the rollers given the small numbers of revolutions.

ccr

Knew from the header a SRAM chain was coming up: they all have
punchmarks on the rollers since they production moved to Portugal. Don't
know if another chain will be quieter.

--
---
Marten Gerritsen

INFOapestaartjeM-GINEERINGpuntNL
www.m-gineering.nl

M-gineering said:

Quoted message said:

Hi

Having recently built a wheel for a fixed gear set up, am now onto the
next problem.

Parts ...

new SRAM PC58 chain 3/32",
new 16 tooth cog (supposed to be 3/32" - bought from the same place as
hub),
well-used 42 tooth chainring reversed, put on outer (still needs to be
1 - 2 mm further out).

The idea is that once I've briefly tested the thing out, I'll get a new
chainring.

Got the chain tension correct (I think) after reading various methods
(e.g. tight as it can be without binding).

Spinning the cranks, there's a regular, light, discrete rubbing coming
from around the cog. Didn't think that was too bad but I took the chain
off and there are two sets of scores/marks along every other roller.
i.e. on one roller the mark is near to lhs plate, next roller the mark
is near to rhs plate.

Any idea what's causing this grinding and how to solve it? It's made
quite a mess of the rollers given the small numbers of revolutions.

ccr

Knew from the header a SRAM chain was coming up: they all have
punchmarks on the rollers since they production moved to Portugal. Don't
know if another chain will be quieter.

That's quite funny. I only have a PC990 and a Sachs PG for comparison
and, of course, they don't have any marks on the rollers so I just
jumped to a conclusion. At least now I know it was already there -
doesn't look very good though.

Wondered what was going on - thought I'd invented a really efficient
pedal-powered grinder!

Cheers for that.

ccr

M-gineering said:

Quoted message said:

Hi

Having recently built a wheel for a fixed gear set up, am now onto the
next problem.

Parts ...

new SRAM PC58 chain 3/32",
new 16 tooth cog (supposed to be 3/32" - bought from the same place as
hub),
well-used 42 tooth chainring reversed, put on outer (still needs to be
1 - 2 mm further out).

The idea is that once I've briefly tested the thing out, I'll get a new
chainring.

Got the chain tension correct (I think) after reading various methods
(e.g. tight as it can be without binding).

Spinning the cranks, there's a regular, light, discrete rubbing coming
from around the cog. Didn't think that was too bad but I took the chain
off and there are two sets of scores/marks along every other roller.
i.e. on one roller the mark is near to lhs plate, next roller the mark
is near to rhs plate.

Any idea what's causing this grinding and how to solve it? It's made
quite a mess of the rollers given the small numbers of revolutions.

ccr

Knew from the header a SRAM chain was coming up: they all have
punchmarks on the rollers since they production moved to Portugal. Don't
know if another chain will be quieter.

And just found the thread 'chain roller pitting/wear' which features a
photo http://flickr.com/photos/vinograd/40539321 . This is exactly the
same as my chain. Again, it's my phrasing that lets me down on the
search-first, ask-second!

Cheers for help.

ccr