Dave Thompson wrote:
> [email protected] wrote:
> <snip>.................... And running the big-big or small-small
> > combinations works too. You just might have some accelerated wear on
> > the parts. Not a big deal really.
> Maybe not a big deal, but a *very expensive* deal if you're running the
> top-end Campy or Shimano stuff. I'm still trying to figure out why riders
> are willing to pay so much for such a small return in 'peformance'.
How expensive do you think it is? How much more quickly does the
small-small or big-big combination wear the chain than the others? 1%
more wear? 10% more wear? What about when you use the next to
smallest or biggest cogs? How much extra wear do they cause than using
the perfectly straight chain position gears?
Lets say you use the small-small or big-big combinations whenever that
gear is the one you need. Lets say instead of getting 3000 miles from
a Campagnolo 9 speed chain, the ones I use, I only get 2500 miles.
2500/3000=.8333. 1-.8333=.1667. 16.67% extra wear. Quite a bit.
Lets say I ride 6000 miles a year. So that would be 2 chains if not
using the small-small or big-big combinations. Or 2.4 chains if I use
the small-small or big-big combinations and get the accelerated 16.67%
wear. I buy my 9 speed Campagnolo chains from Nashbar on sale for $20
each. These are the Record 9 speed chains. So the extra wear would
cost me $8 extra per year.
A similar scenario can be done for cassettes. Lets say 9,000 miles use
from a Campagnolo 9 speed ti/steel Record cassette when not using the
small-small or big-big combinations. I had a Record ti/steel 9 speed
cassette in the late 90s and I think it lasted about this long. Lets
assume the same 16.67% accelerated wear. 83.33% * 9,000 = 7,500 miles.
Using the same 6,000 miles riding per year, we use .67 of the cassette
if not using the big-big or small-small combinations. We use .8 of the
cassette if we use the big-big or small-small combinations whenever we
want. An extra .13 of the cassette is used in a year of riding. Lets
assume a price of $200 for a Record ti/steel 9 speed cassette. I can't
find anyone selling them anymore and this $200 is a little less than
the 10 speed ti/steel cassette. So the extra cost per year is $200 *
..13 = $26.
So Dave Thompson thinks an extra $34 of chain and cassette wear per
year is very expensive if using the top end stuff.