12-27 vs 12-25

"Donald Specker" wrote:

I currently have an 11-23 on my Ultegra double and need more range. Should
I go for the 12-27, or are there shifting issues, etc., that would steer me
toward the 12-25. I can ride the 23, but have developed some "over-use"
type injuries from riding the hills around here.

I've got 12-25 on one bike, and 12-27 on another. I don't notice any
gaps on the 12-27, and it's nice to have the 27 when I need it. If
you're going to make a change, go for the 12-27.

The only difference is the last two cogs:

12-....21-23-25

vs.

12-....21-24-27

Art Harris

belij3- So ........ a 46/12 should do the same? BRBR

yes, but I am a freewheel kinda guy and still have a lot of 13-23 7s
freewheels...

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"

On Sat, 26 Jul 2003 11:57:44 -0700, Bill Davidson
wrote:
But too many road bikes are 175mm cranks and a 11-23/53-39...WAY to tall
for most riders...

Agreed. That's a racer's setup for a fairly strong rider.

I agree also, with 39 x 23 being the easiest combo, that's tough.
My Giant TCR2 came with 39-52 x 12-25, and that's pretty darn tall
for the hills around here. I went to a 12-27 recently, and once I
get the new stem on for a better fit, I think I'll find it
significantly easier.

But, regarding this whole thread:

I was thinking while riding today (dangerous combination!), and
here's what I don't understand about this thread:

-People who are against wide-range cassettes, or at least
cassettes with 11 at the tall end, feel that close ratios
are better. This is because they feel that pedalling is
more efficient at a constant cadence.

-Yet, they then go on to say "I go XX mph when in XX x XX
gear, by spinning up to XXX rpm".

Personally, I find that putting a larger cadence range into each
gear before shifting, and having wider ratios, is easier for me.

Instead of constantly going 83.213 rpm through each of the 9
speeds of my cassette, then spinning up to 150 rpm when I want to
go faster down a hill, I prefer to let my cadence vary from maybe
70 to 90 in most gears; then in 53 x 11, I can spin up to 120 rpm
and still be putting some _torque_ into it. [Note: I can almost
spin out my TCR2 with it's 52x12, and I could certainly go faster
with 53x11).

With 48 x 13, I spin out completely. As I get closer to 53 x 11,
I can spin up with some actual results.

My MTB has an 11-34 cassette, and the crankset is something to
the effect of 26-36-48 or 28-38-48 (It's a Deore with the smallest
granny ring that fits). I use every combination that doesn't cross
up, very effectively. This is because I'm a clydesdale, and a weak
one at that.

I wish my road bikes had the same gearing except with the 53 large
ring. I'd be unstoppable! I could tow a car, and hit 50mph downhill!

--
Rick Onanian

On Sat, 26 Jul 2003 11:57:44 +0000, Bill Davidson wrote:

How about a 22-32-42 on the front for a touring bike? I don't it would be
unreasonable to have an 11x34 in the back.

With the 22 on the front, would you really need the 34 in back? Actually,
though, those cranks are quite fine for touring. But you shouldn't need
such a low gear as the 22/34 unless you are going heavily loaded, long
distance, and pulling stumps along the way for extra cash.

I head out on Wednesday, with a 46/30/20 and a 12/23 rear. Plenty low
enough for a lightly loaded tour.

*Deraileurs only have so much
capacity and just because you're loaded with stuff doesn't mean you
necessarily want to coast down every hill.

My top speed in the past year or so was on a trour. I was still
coasting, though, but at 50 mph.

--

David L. Johnson

__o | It doesn't get any easier, you just go faster. --Greg LeMond
_`\(,_ |
(_)/ (_) |

Rick Onanian wrote:
-People who are against wide-range cassettes, or at least
cassettes with 11 at the tall end, feel that close ratios
are better. This is because they feel that pedalling is
more efficient at a constant cadence.

No, I don't - I'm against small 11s because most of the time they're
about as useful as a rubber crutch.

I have a seven-speed 13-34 (not MegaRange) which certainly does not
provide close ratios - close enough for me, but not for the "must pedal at
exactly 85rpm" crowd. I mount a double with as large and as small a
chainring as possible; currently a 52/39, but with a 52/34 on the way.

There's no point in me mounting an 11t - 120rpm in 52x13 on 700x25C is
good for 37.7 MPH, but I would never pedal up to above 30MPH in any case -
but there's a point to the 34t because there's always a steeper hill and a
heavier load.
--
David Damerell Kill the tomato!

On 28 Jul 2003 15:55:35 +0100 (BST), David Damerell
wrote:
There's no point in me mounting an 11t - 120rpm in 52x13 on 700x25C is
good for 37.7 MPH, but I would never pedal up to above 30MPH in any case -

There's no point for you. That doesn't mean that somebody else
doesn't want to chase some thrills at higher speeds.

but there's a point to the 34t because there's always a steeper hill and
a heavier load.

Absolutely, 100% agreed. I wish I could come up with some easier
gearing on my TCR2, but it's just too damn expensive after all is
said and done...

--
Rick Onanian

Rick Onanian wrote:
wrote:
There's no point in me mounting an 11t - 120rpm in 52x13 on 700x25C is
good for 37.7 MPH, but I would never pedal up to above 30MPH in any case -
There's no point for you. That doesn't mean that somebody else
doesn't want to chase some thrills at higher speeds.

These somebody elses could do with considering the very minimal effect of
pedalling at these high speeds - there's a point where flapping your legs
about exerts such an aero penalty as to mean you're not actually doing
any good, and we're definitely starting to talk about those kinds of
speeds.

but there's a point to the 34t because there's always a steeper hill and
a heavier load.
Absolutely, 100% agreed. I wish I could come up with some easier
gearing on my TCR2, but it's just too damn expensive after all is
said and done...

Gearing's dirt cheap, at least at first - a new cassette and a long-cage
derailleur. When you start to break out of the 130mm BCD jail it's a
little more pricy, unless you had the foresight to get a triple...
--
David Damerell Distortion Field!

David Damerell wrote:


These somebody elses could do with considering the very minimal effect of
pedalling at these high speeds - there's a point where flapping your legs
about exerts such an aero penalty as to mean you're not actually doing
any good, and we're definitely starting to talk about those kinds of
speeds.

Here is a case of someone theorizing about something of which he knows nothing.

David Damerell wrote in message ...
Rick Onanian wrote:
wrote:
There's no point in me mounting an 11t - 120rpm in 52x13 on 700x25C is
good for 37.7 MPH, but I would never pedal up to above 30MPH in any case -
There's no point for you. That doesn't mean that somebody else
doesn't want to chase some thrills at higher speeds.

These somebody elses could do with considering the very minimal effect of
pedalling at these high speeds - there's a point where flapping your legs
about exerts such an aero penalty as to mean you're not actually doing
any good, and we're definitely starting to talk about those kinds of
speeds.

more rubbish. Aero has nothing to do with it. You've got your
fundamentals wrong; in this case, the rider's goals.

dkl

On 29 Jul 2003 13:18:39 +0100 (BST), David Damerell
wrote:
There's no point for you. That doesn't mean that somebody else
doesn't want to chase some thrills at higher speeds.

These somebody elses could do with considering the very minimal effect of
pedalling at these high speeds - there's a point where flapping your legs
about exerts such an aero penalty as to mean you're not actually doing
any good, and we're definitely starting to talk about those kinds of
speeds.

This may be true at high cadences, but with a tall enough gear,
some speed could be added.

Absolutely, 100% agreed. I wish I could come up with some easier
gearing on my TCR2, but it's just too damn expensive after all is
said and done...

Gearing's dirt cheap, at least at first - a new cassette and a long-cage
derailleur. When you start to break out of the 130mm BCD jail it's a
little more pricy, unless you had the foresight to get a triple...

I got a new cassette that's compatible with my derailleur; I had
priced, as a whole, new front & rear ders & cassette & crankset,
which I think required new shifters also, but I hadn't seriously
considered just going to a new rear der and a wide-range cassette.

****. I just wasted a pile of money at the LBS just to get a few
more teeth, when I could have have 10 or 15 more teeth...probably
for not much more $$$. I gotta get the tool for the cassette and
fool with it myself, I guess.

Any reason a long-cage rear der wouldn't replace my short-cage 105
easily? I thought my wrench told me I'd need a new shifter, but
that may have only been part of the triple-crankset conversion
discussion.

--
Rick Onanian