Chainrings and cogs number

Hello,

I am restoring a bike with a badly worn transmission, so I will change
both chain, cogs and chainrings. It has a freehub with 8 cogs, and 3
chainrings.

Since these chainrings are replaceable, I prefer to buy them separately
rather than buying an entire crankset. I am not fond of dumping hardware
for no reason, in this case the existing cranks.

I see that chainrings are labelled for a number of cogs, e.g. 7/8, 9 or
more. I assume that this is because, when you have a large number of
cogs, you need a thin chain so it does not touch the next cog, and thin
chainrings to fit into the chain links.

If this is so, using a chainring designated for 9 cogs would not be a
real issue on my bike that has 8 cogs and a chain for 8 cogs as well,
would it?

--
Tanguy

On 9/1/2020 5:33 AM, Tanguy Ortolo wrote:
Hello,

I am restoring a bike with a badly worn transmission, so I will change
both chain, cogs and chainrings. It has a freehub with 8 cogs, and 3
chainrings.

Since these chainrings are replaceable, I prefer to buy them separately
rather than buying an entire crankset. I am not fond of dumping hardware
for no reason, in this case the existing cranks.

I see that chainrings are labelled for a number of cogs, e.g. 7/8, 9 or
more. I assume that this is because, when you have a large number of
cogs, you need a thin chain so it does not touch the next cog, and thin
chainrings to fit into the chain links.

If this is so, using a chainring designated for 9 cogs would not be a
real issue on my bike that has 8 cogs and a chain for 8 cogs as well,
would it?


No problem at all. Campagnolo techs told us clearly that
the Ten and 1st-gen Eleven rings are identical parts until
labeled. (the crank web is smaller on 11).

You'll run into problems running a skinny chain on a 5/6
speed crank as the chain can jam between chainrings. A fat
chain on a modern crank will drag the outer when in low
chainring more annoyingly than the correct chain.

Generally use the widest compatible chain. For an 8 cassette
with 9 or Ten rings, use the Eight chain. Where there's a
big discrepancy (12 speed crank with a five speed system)
expect difficulties but 1 or 2 formats' difference is
negligible for chainrings.

Also any derailleur chain will engage any chainring's teeth
so on a single front ring system this doesn't matter at all.

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

AMuzi, 2020-09-01 14:48+0200:
On 9/1/2020 5:33 AM, Tanguy Ortolo wrote:
If this is so, using a chainring designated for 9 cogs would not be a
real issue on my bike that has 8 cogs and a chain for 8 cogs as well,
would it?

No problem at all. Campagnolo techs told us clearly that
the Ten and 1st-gen Eleven rings are identical parts until
labeled. (the crank web is smaller on 11).

Thank you for confirming my intuition. By the way, the reason I am
asking is because it is sometimes easier to find the chainrings I want
for 9 speeds than for 8 speeds.

I now have to work out a relevant selection of cogs and chainrings, that
would provide regularly spaced ratios.

--
Tanguy

On Tuesday, September 1, 2020 at 8:24:31 AM UTC-7, Tanguy Ortolo wrote:
AMuzi, 2020-09-01 14:48+0200:
On 9/1/2020 5:33 AM, Tanguy Ortolo wrote:
If this is so, using a chainring designated for 9 cogs would not be a
real issue on my bike that has 8 cogs and a chain for 8 cogs as well,
would it?

No problem at all. Campagnolo techs told us clearly that
the Ten and 1st-gen Eleven rings are identical parts until
labeled. (the crank web is smaller on 11).
Thank you for confirming my intuition. By the way, the reason I am
asking is because it is sometimes easier to find the chainrings I want
for 9 speeds than for 8 speeds.

I now have to work out a relevant selection of cogs and chainrings, that
would provide regularly spaced ratios.

--
Tanguy
If you're not jumping right in let me go through the cogsets I have to see if I have either an 8 or 9. I'd give it to you for postage.

Tom Kunich, 2020-09-02 01:03+0200:
On Tuesday, September 1, 2020 at 8:24:31 AM UTC-7, Tanguy Ortolo wrote:
I now have to work out a relevant selection of cogs and chainrings, that
would provide regularly spaced ratios.

If you're not jumping right in let me go through the cogsets I have to see if I have either an 8 or 9. I'd give it to you for postage.

I am not at all in a hurry indeed, since this is one of the bikes I am
setting up at my parent's holiday home, and I am not there at the
moment.

--
Tanguy

On Wednesday, September 2, 2020 at 12:40:18 AM UTC-7, Tanguy Ortolo wrote:
Tom Kunich, 2020-09-02 01:03+0200:
On Tuesday, September 1, 2020 at 8:24:31 AM UTC-7, Tanguy Ortolo wrote:
I now have to work out a relevant selection of cogs and chainrings, that
would provide regularly spaced ratios.

If you're not jumping right in let me go through the cogsets I have to see if I have either an 8 or 9. I'd give it to you for postage.
I am not at all in a hurry indeed, since this is one of the bikes I am
setting up at my parent's holiday home, and I am not there at the
moment.

--
Tanguy
I'll try to go through them today.

On Wednesday, September 2, 2020 at 9:17:40 AM UTC-7, Tom Kunich wrote:
On Wednesday, September 2, 2020 at 12:40:18 AM UTC-7, Tanguy Ortolo wrote:
Tom Kunich, 2020-09-02 01:03+0200:
On Tuesday, September 1, 2020 at 8:24:31 AM UTC-7, Tanguy Ortolo wrote:
I now have to work out a relevant selection of cogs and chainrings, that
would provide regularly spaced ratios.

If you're not jumping right in let me go through the cogsets I have to see if I have either an 8 or 9. I'd give it to you for postage.
I am not at all in a hurry indeed, since this is one of the bikes I am
setting up at my parent's holiday home, and I am not there at the
moment.

--
Tanguy
I'll try to go through them today.
I have four or five 9-speed Campy 9 speed cogsets, but after looking up the mailing costs, you would be better buying them there.

Tom Kunich, 2020-09-02 22:38+0200:
I have four or five 9-speed Campy 9 speed cogsets, but after looking up the mailing costs, you would be better buying them there.

No problem, since I just need a basic cassette, buying a new one is not
really that expensive. :-) Thanks for looking.

--
Tanguy