Does Chainline Matter Much?

I have read of a gearing arrangement (or perhaps it could be called a shifting ideal) called
"nine-in-a-line" from the days of 5 speed freewheels used with a triple crankset. As I understand it
the idea was to use the outer chainring just with the outer 3 freewheel cogs, the middle chainring
with the middle 3 cogs, and the inner chainring with the inner 3 cogs. It makes sense because then
the chainline would never be more than one position off perfectly straight.

Now however a mix of really wide clusters with 8, 9, 10 cogs (and more to come no doubt) combined
with short chainstays makes for chainlines with lots of deflection.

Does chainline matter less than those nine-in-a-line guy thought or have chains gotten better so
they can accept the greater defection (or bending or whatever term you want to use. Lets not get
into a semantic argument about the choice of one word when it's clear what is intended). Or is it
just that we've gotten so obcessed about judging the technical merit of a drivetrain by counting the
number of cogs that we simply ignore chainline?

From time to time I've also wondered what will happen when clusters grow to such a large number of
cogs that even one-tooth jumps result in a largest cog that exceeds the macho limit of say 23 teeth?
Will special cassettes have to be made with the last 3 or so cogs all 23 teeth to avoid the
extra-small-jockstrap stigma that might be a problem for some? But then what about the extra weight
of those surplus cogs (horrors)?

Bob Taylor

 

On Mon, 10 Mar 2003 09:57:03 -0500, Robert Taylor wrote:

> Does chainline matter less than those nine-in-a-line guy thought or have chains gotten better so
> they can accept the greater defection (or bending or whatever term you want to use.

Chains definitely have gotten more flexible than they were back in 5-speed freewheel days.

 

> Chains definitely have gotten more flexible than they were back in 5-speed freewheel days.

Flexible? Or simply larger tolerances to allow for more movement between links? Quite the
difference.

Most competent cyclists only use maybe 15 or 20 of the 27 speeds normally available, at least if
they value their chain.

Divide the rear cog into thirds and use each third with each corresponding chainring in front to
extend the life of ur stuff.

--
Phil, Squid-in-Training

 

On Tue, 11 Mar 2003, Phil, Squid-in-Training wrote:

> > Chains definitely have gotten more flexible than they were back in 5-speed freewheel days.
>
> Flexible? Or simply larger tolerances to allow for more movement between links? Quite the
> difference.

Why is that different? The bits aren't going to bend, so any flex in the chain is due to, designed
in, movement between the links.

> Most competent cyclists only use maybe 15 or 20 of the 27 speeds normally available, at least if
> they value their chain.

Hmm, I've seen quite a few competent cyclists who use 'cross chained' gears. It does reduce chain
and cog life, but not as much as you seem think. The real cause of reduced chain life is grit
getting into the bushings. Then the chain gets 'stretched' because the bushing wear. When the
chain's spacing no longer matches the sprocket's spacing, things rapidly wear out.

> Divide the rear cog into thirds and use each third with each corresponding chainring in front to
> extend the life of ur stuff.

I get 6,000 mile or so from chains, maybe 15,000 from a set of cogs, and more from rings. I also
use almost all gear combinations. Instead of your 1/3, 1/3, 1/3, I use (granny) 7/9, (middle) 9/9,
(big) 6/9. More importantly, I clean and lube my chain when it needs it, and I get long chain,
ring, and cog life.

Mark <http://www.cs.unca.edu/~boyd/bicycling.html

 

Hi Mark- I clean my chain every 1-2 weeks. Doesn't help- by the time it reaches 1000 mi I need to
replace it (I could let it go longer but I don't want to wear out my cogs). Must be all that road
salt and sand up here in New England. And yes, I try to maintain a chain line.- Gary

Mark Boyd wrote:

> On Tue, 11 Mar 2003, Phil, Squid-in-Training wrote:
>
> > > Chains definitely have gotten more flexible than they were back in 5-speed freewheel days.
> >
> > Flexible? Or simply larger tolerances to allow for more movement between links? Quite the
> > difference.
>
> Why is that different? The bits aren't going to bend, so any flex in the chain is due to, designed
> in, movement between the links.
>
> > Most competent cyclists only use maybe 15 or 20 of the 27 speeds normally available, at least if
> > they value their chain.
>
> Hmm, I've seen quite a few competent cyclists who use 'cross chained' gears. It does reduce chain
> and cog life, but not as much as you seem think. The real cause of reduced chain life is grit
> getting into the bushings. Then the chain gets 'stretched' because the bushing wear. When the
> chain's spacing no longer matches the sprocket's spacing, things rapidly wear out.
>
> > Divide the rear cog into thirds and use each third with each corresponding chainring in front to
> > extend the life of ur stuff.
>
> I get 6,000 mile or so from chains, maybe 15,000 from a set of cogs, and more from rings. I also
> use almost all gear combinations. Instead of your 1/3, 1/3, 1/3, I use (granny) 7/9, (middle) 9/9,
> (big) 6/9. More importantly, I clean and lube my chain when it needs it, and I get long chain,
> ring, and cog life.
>
> Mark <http://www.cs.unca.edu/~boyd/bicycling.html