X
Xyzzy
Guest
Where I live I am very happy with a 11-21 cassette... I like having
very small gaps between the sprockets... I do spend quite a bit of time
in the 19 and 21 when I climb seated... We don't have any hills where I
live that I can't climb seated with the 21 or standing with the 17 or
18... None of our hills is more than 200-300 feet tall so we aren't
talking more than a minute or two... I have noticed that the 19 and 21
sprockets show accelerated wear though... I don't mean they start
skipping or anything... They just get real ugly marks on them from the
chain hitting them at an angle... I also noticed I wear out chains a
lot faster... I noticed this because I am temporarily running a 12-25
right now and my chain has lasted easily twice as long as my old chains
did with the 11-21... I'm still using a max of 21 so the 23 and 25
never get touched... With the 11-21 I get around 2000 miles out of a
chain but with the 12-25 the chain is still measuring like new at 2000
miles... I usually replace the cassette at 4000 miles just to be
safe...
I could change the cassette to a 13-26 and have a straight block from
13 to 19, and use the 23 and 26 as spacers to clean up the chain line,
but this seems a bit wasteful, since I would never use those gears and
I really would like to have the 12... I have no use for an 11 but it
does clean up the chain line a bit when I am in the small ring... I
plan to switch to a Chorus cassette next time I buy one and I have
figured out how to make an all steel 11-21 by taking an existing 11-23
Chorus cassette and replacing the last two pinned sprocket pairs with a
10S-78C and a 10S-91C... The 12-25 I have right now works fine but I do
miss the 18...
My questions:
1) Will the steel 17, 18, 19 and 21 wear a lot better than the titanium
versions, or will they still wear out fast due to the chain line not
being optimal? Well, I know they will wear better of course, but will
they wear a lot better? Or am I asking too much from the system with
the crazy chain angles?
2) In the big picture, what "ranking" does chain cleanliness, chain
line, sprocket size and torque applied to the chain affect wear? I have
read that the smaller sprockets wear faster due to having less teeth to
distribute the wear and because the chain has to flex more when it
passes over them... I am guessing that how hard you pedal affects
sprocket wear too... I just wonder if torque is an order of magnitude
more important to chain/sprocket wear than chain line, or vice versa...
Like, would you say the wear breakdown is torque 70%, sprocket size
15%, chain line $10% and cleanliness 5%?
3) Will the spacer effect from a 13-26 be worth the trouble given I
never will use those gears?
There are several reasons why I like a corn cob cassette... It allows
me to run a very short chain (104 versus 108) which makes shifting seem
a bit cleaner, and it keeps the chain from whacking around in some gear
combos when there is some slack... I can also dial in the B screw to
get the upper pulley real close to the cassette which seems to make
shifting even cleaner... I will also admit to liking the corn cob look
better than a pie pan look, and like I mentioned before, a 21 is all I
really need...
PS - I really don't need the 11... I am considering the 12-23 as well,
except it is impossible to make an all steel 12-23...
PPS - I'm not cross chaining from the 53 very much... On my bike the
chainstays are so short I get pretty big angles going from the 39...
And yes, it is set up properly...
Thanks!
--
Mike (Xyzzy)
very small gaps between the sprockets... I do spend quite a bit of time
in the 19 and 21 when I climb seated... We don't have any hills where I
live that I can't climb seated with the 21 or standing with the 17 or
18... None of our hills is more than 200-300 feet tall so we aren't
talking more than a minute or two... I have noticed that the 19 and 21
sprockets show accelerated wear though... I don't mean they start
skipping or anything... They just get real ugly marks on them from the
chain hitting them at an angle... I also noticed I wear out chains a
lot faster... I noticed this because I am temporarily running a 12-25
right now and my chain has lasted easily twice as long as my old chains
did with the 11-21... I'm still using a max of 21 so the 23 and 25
never get touched... With the 11-21 I get around 2000 miles out of a
chain but with the 12-25 the chain is still measuring like new at 2000
miles... I usually replace the cassette at 4000 miles just to be
safe...
I could change the cassette to a 13-26 and have a straight block from
13 to 19, and use the 23 and 26 as spacers to clean up the chain line,
but this seems a bit wasteful, since I would never use those gears and
I really would like to have the 12... I have no use for an 11 but it
does clean up the chain line a bit when I am in the small ring... I
plan to switch to a Chorus cassette next time I buy one and I have
figured out how to make an all steel 11-21 by taking an existing 11-23
Chorus cassette and replacing the last two pinned sprocket pairs with a
10S-78C and a 10S-91C... The 12-25 I have right now works fine but I do
miss the 18...
My questions:
1) Will the steel 17, 18, 19 and 21 wear a lot better than the titanium
versions, or will they still wear out fast due to the chain line not
being optimal? Well, I know they will wear better of course, but will
they wear a lot better? Or am I asking too much from the system with
the crazy chain angles?
2) In the big picture, what "ranking" does chain cleanliness, chain
line, sprocket size and torque applied to the chain affect wear? I have
read that the smaller sprockets wear faster due to having less teeth to
distribute the wear and because the chain has to flex more when it
passes over them... I am guessing that how hard you pedal affects
sprocket wear too... I just wonder if torque is an order of magnitude
more important to chain/sprocket wear than chain line, or vice versa...
Like, would you say the wear breakdown is torque 70%, sprocket size
15%, chain line $10% and cleanliness 5%?
3) Will the spacer effect from a 13-26 be worth the trouble given I
never will use those gears?
There are several reasons why I like a corn cob cassette... It allows
me to run a very short chain (104 versus 108) which makes shifting seem
a bit cleaner, and it keeps the chain from whacking around in some gear
combos when there is some slack... I can also dial in the B screw to
get the upper pulley real close to the cassette which seems to make
shifting even cleaner... I will also admit to liking the corn cob look
better than a pie pan look, and like I mentioned before, a 21 is all I
really need...
PS - I really don't need the 11... I am considering the 12-23 as well,
except it is impossible to make an all steel 12-23...
PPS - I'm not cross chaining from the 53 very much... On my bike the
chainstays are so short I get pretty big angles going from the 39...
And yes, it is set up properly...
Thanks!
--
Mike (Xyzzy)