Double vs. Compact

Wasatch5k said:

Double tooth count- 53/39
Compact tooth count- 50/34

How big of a difference with the 3 or 4 tooth difference make? I live in
the rockies and tend to climb a lot of canyons. I'm a little timid to
get a double for fear of not being able to climb some hills. The compact
I am looking at is the FSA Energy. It takes 110 BCD rings. The Double
takes 130 BCD rings. I figure a compact gives me more ring configuration
options including really close to the same gear ratio as the standard
double. The standard double will not let you get rings much smaller
because of the bolt spacing. Is a compact a good solution or would a
triple be better.

Thanks,

Wasatch

This link could be useful to compare your current gears with the choice
given by a compact:
http://www.sheldonbrown.com/gears/

In my opinion the compact is a really good solution!

Francesco

Wasatch5k says...

Quoted message said:

Double tooth count- 53/39
Compact tooth count- 50/34

How big of a difference with the 3 or 4 tooth difference make? I live in
the rockies and tend to climb a lot of canyons. I'm a little timid to
get a double for fear of not being able to climb some hills. The compact
I am looking at is the FSA Energy. It takes 110 BCD rings. The Double
takes 130 BCD rings. I figure a compact gives me more ring configuration
options including really close to the same gear ratio as the standard
double. The standard double will not let you get rings much smaller
because of the bolt spacing. Is a compact a good solution or would a
triple be better.

Thanks,

Wasatch

Do yourself a favor and get the compact. Even with a 13 tooth cog, you
will be able to go 25mph at 80rpm. It's flat where I live, and someday I
will be changing out my 12-25 cassette for a 13-29. Lance may need a
53/11, but I don't.

Wasatch5k said:

Double tooth count- 53/39
Compact tooth count- 50/34

How big of a difference with the 3 or 4 tooth difference make? I live in
the rockies and tend to climb a lot of canyons. I'm a little timid to
get a double for fear of not being able to climb some hills. The compact
I am looking at is the FSA Energy. It takes 110 BCD rings. The Double
takes 130 BCD rings. I figure a compact gives me more ring configuration
options including really close to the same gear ratio as the standard
double. The standard double will not let you get rings much smaller
because of the bolt spacing. Is a compact a good solution or would a
triple be better.

Thanks,

Wasatch

I vote get the triple. Because I use one and I love it. You're no longer
limited by not having enough gears, but you're still limited by the engine.

Kenny

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In article <[email hidden]>,

Wasatch5k said:

Double tooth count- 53/39
Compact tooth count- 50/34

How big of a difference with the 3 or 4 tooth difference make? I live in
the rockies and tend to climb a lot of canyons. I'm a little timid to
get a double for fear of not being able to climb some hills. The compact
I am looking at is the FSA Energy. It takes 110 BCD rings. The Double
takes 130 BCD rings. I figure a compact gives me more ring configuration
options including really close to the same gear ratio as the standard
double. The standard double will not let you get rings much smaller
because of the bolt spacing. Is a compact a good solution or would a
triple be better.

_ The big advantage of a triple over a double compact is not the
range of gears, for road use generally you can get a low enough
gear with either unless you want something lower than 34/34,
the big advantage of a triple is more selection of low gears.
Generally, people get compacts to get just one or two lower
gears without having to change the rest of their components.

_ If you're just starting out and there are no other
considerations ( money, parts you already have, etc ),
I would get a triple. It's much better to have gears
you don't need than need gears you don't have. Those
long canyon climbs can be a lot easier if you can have
a "break" every once in a while. However, if you already
have a bike with a standard double and are a fairly
strong climber, then I think the compact would be a
good choice. It gives you a "safety net" without requiring
a large investment in other parts.

_ Booker C. Bense

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Wasatch5k said:

Double tooth count- 53/39
Compact tooth count- 50/34

How big of a difference with the 3 or 4 tooth difference make?

The difference between a 39 and a 34 is significant. Some folks in
the local club have compacts on their climbing bikes. They stand a
lot less than when on their standard bikes.

Quoted message said:

I live in the rockies and tend to climb a lot of canyons. I'm a
little timid to get a double for fear of not being able to climb
some hills.

Roads in the Rockies tend to have moderate grades, so a 39/27 may
be good enough.

Quoted message said:

The compact I am looking at is the FSA Energy.

It's a good choice. I see a lot of them in use, and the owners seem
very happy with them.

Quoted message said:

Is a compact a good solution or would a triple be better.

A triple will give you a wider ratio than the compact double, but a
triple requires different components (shifter, derailleur, bottom
bracket). I have the FSA triple (53/42/30), and I find the 30
useful on grades above about 12%. The 53 is nice in fast pace
lines, also.
--
terry morse Palo Alto, CA http://bike.terrymorse.com/

Wasatch5k <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Double tooth count- 53/39
Compact tooth count- 50/34

How big of a difference with the 3 or 4 tooth difference make? I live in
the rockies and tend to climb a lot of canyons. I'm a little timid to
get a double for fear of not being able to climb some hills. The compact
I am looking at is the FSA Energy. It takes 110 BCD rings. The Double
takes 130 BCD rings. I figure a compact gives me more ring configuration
options including really close to the same gear ratio as the standard
double. The standard double will not let you get rings much smaller
because of the bolt spacing. Is a compact a good solution or would a
triple be better.

Thanks,

Wasatch

I also live in the Rockies and do long rides with lots of canyon
climbs. In the last couple of years, my knees didn't like the big
climbs towards the end of the rides. Last summer I switched from 39-53
double to 34-50 compact. I now use an 11-23 cassette for most rides
(instead of 12-27), and I built an 11-27 for those steep/long rides.
It has worked out great - I get a couple of smaller bailout gears, and
about the same top end. Another advantage of this setup - you can save
weight on both the crankset and the cassette. Seems like a good move
to me.

Alan

Get a triple if you are in the mountains. Get a 135 or 130 mm bcd
double for other parts of the country. Use a 110 mm bcd double if
its given to you free or you have it laying around or just want to
monkey with it to get in on the current fad.

Going from a 39 to a 34 gets you one lower gear roughly. About 4-5
gear inches. A 39x26 is identical to a 34x23. Both right at 39 gear
inches. A 34x26 is 35 gear inches. One lower gear roughly. I've
ridden in the mountains and I wanted more than just one lower gear.
The triple provides many lower gears. A 30x26 is 31 gear inches. A
28x26 is 29 gear inches. A 26x26 is 27 gear inches. You can get much
lower gears with a triple crankset.

The 110 mm bcd double with the usual configuration of 50/34 chainrings
gives terrible gaps between gears. Unless you change to a cassette
such as 11-21. If you use a 13-26 cassette for instance, the 34 ring
produces too low of gears to use unless you are riding about 12 mph.
And the large ring has too big of gaps between gears when riding
around 20 mph. In my everyday riding I use a 42 inner ring with a
13-26 cassette. The 42 with 13 to 17 straight block gives nice 5 gear
inch changes that are just right for riding between 15 to 29 mph. And
then the 19 and 21 cogs are OK changes in gear inches too.

With the compact 110 mm bcd double crank, the outer ring of 50 or 48
gives too large 8 to 10 gear inch changes between cogs. And the 34
inner ring just doesn't give high enough gears for the mph range I
ride in. Unless you go to something like a 11-21 cassette. In which
case the 50 outer ring is then useless for anything except going down
mountains.

Wasatch5k <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Double tooth count- 53/39
Compact tooth count- 50/34

How big of a difference with the 3 or 4 tooth difference make? I live in
the rockies and tend to climb a lot of canyons. I'm a little timid to
get a double for fear of not being able to climb some hills. The compact
I am looking at is the FSA Energy. It takes 110 BCD rings. The Double
takes 130 BCD rings. I figure a compact gives me more ring configuration
options including really close to the same gear ratio as the standard
double. The standard double will not let you get rings much smaller
because of the bolt spacing. Is a compact a good solution or would a
triple be better.

Thanks,

Wasatch

Someone who wisely concealed his or her secret identity said:

Double tooth count- 53/39
Compact tooth count- 50/34

How big of a difference with the 3 or 4 tooth difference make?

That's actually a 5 tooth difference.

The difference in the low gears would be 12.5% according to my trusty
slide rule.

Sheldon "Numbers Are Good" Brown
+----------------------------------------------------------------+
| Anyone who cannot cope with mathematics is not fully human. |
| At best he is a tolerable subhuman who has learned to wear |
| shoes, bathe, and not make messes in the house. |
| --Robert A. Heinlein |
+----------------------------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

Terry Morse said:

Wasatch5k wrote:

Quoted message said:

Quoted message said:

Double tooth count- 53/39
Compact tooth count- 50/34

How big of a difference with the 3 or 4 tooth difference make?

Quoted message said:

The difference between a 39 and a 34 is significant. Some folks in
the local club have compacts on their climbing bikes. They stand a
lot less than when on their standard bikes.

When your cadence dips below about 70 rpm, your muscles are using pre-
stored glycogen (fast-burning body sugars.) There is only a 10-minute
supply that is stored in the muscles of the body. These "fast burn"
carbohydrates cannot be easily replenished during a bike ride.

When you can climb at a higher cadence like 90, 100, or 110 rpm, you
can use glucose, and your body has 2 hrs of this fuel before it needs
to be replenished. More importantly, it can easily be replenished
during a ride by eating bananas or by consuming energy drinks. This
is why a marathon is a 2-hr race and this is why tour-de-france riders
eat continually during their races.

Therefore, with a compact crankset or a triple, you will likely to be
able to climb all day long, no matter what your fitness level. With
the steeper 39/53T crankset, you will likely be limited to 10 minutes
a day of intense climbing.

- Don Gillies
San Diego, CA

In article <[email hidden]>,

Wasatch5k said:

Double tooth count- 53/39
Compact tooth count- 50/34

How big of a difference with the 3 or 4 tooth difference make?

About a cog's worth.

Quoted message said:

Is a compact a good solution or would a triple be better.

It depends on how high you want, how low you want, how many cogs you have,
and what sort of gear spacing you like.

Play with the numbers.

39x28 is about the same as 34x24 or 30x21. You can go lower or keep the same
ends and add more gears in the middle.

I weigh about 150 pounds, live in Boulder, and think a 42x28 is as low as
I want for everything except Magnolia Road or if I have a couple days of
hard climbing in a row. I think a 52 x 14 is plenty on the high end.
I also like tight gears although pushing the 42x21 up the hills on
a 13-21 six speed freewheel wouldn't be pleasant.

With 8 speeds and a 135mm/74mm bolt circle I could have my preferred
big, small, and middle gears : 50-40-30 x 13-14-15-16-17-18-19-21.

I really like having the 16 and 18 cogs, and a nice side effect when going
down to the next ring I can move both shifters at the same time and get to
what's essentially one gear lower.

When forced to upgrade to 9 speeds I added a 23 to the end with the same
crank. It improves the chainline on my bigring but doesn't get used with the
little ring.

34x23 is close enough to 42x28 so I've decided to try a 50-34 compact
double - the bottom bracket shows up today. Campy rear ergo shifters can only
go up three notches at once so I'll essentially drop two gears when changing
rings and cogs like that.

Once my 13-23 wears out, I'll probably try 50-36 x 13-26 to get the same
double-shifting behavior and a bit lower gear.

If you don't care about the 18 you could just run 50-39 x 13-29.

YMMV. 53-39 really only makes sense when have a 6 speed corncob
and want tight gears with minimal overlap. With 9 or 10 cogs it's a
bit silly.

--
<a href="http://www.poohsticks.org/drew/">Home Page</a>
Life is a terminal sexually transmitted disease.

In article <[email hidden]>,

Donald Gillies said:

When your cadence dips below about 70 rpm, your muscles are using pre-
stored glycogen (fast-burning body sugars.) There is only a 10-minute
supply that is stored in the muscles of the body.

Do you have a reference for this? Doesn't intensity level factor into
that somewhere?

Wasatch5k said:

Double tooth count- 53/39
Compact tooth count- 50/34

How big of a difference with the 3 or 4 tooth difference make?

Quite a lot. It's like going from a 25 to (almost) a 29 on the back. A
12-25 cassette will still give you a 110" top gear, which is good enough
for anything.

Wasatch5k said:

Double tooth count- 53/39
Compact tooth count- 50/34

How big of a difference with the 3 or 4 tooth difference make?

The difference between the 53 & 50:

Quoted message said:

Quoted message said:

StepSize = 100*geomeanstep([53 50])

StepSize =
5.8277

The difference between the 39 & 34:

Quoted message said:

Quoted message said:

StepSize = 100*geomeanstep([39 34])

StepSize =
13.7309

How you judge these percentage differences is related to what *you* decide to
call a "gear step." If you call a gear step 8% difference, then you get the
idea. Under that definition, the change between the 53 & 50 is a "under one
gear step." The difference between the 39 & 34 is about 1.5 gears, according to
the given definition.

Quoted message said:

I live in
the rockies and tend to climb a lot of canyons. I'm a little timid to
get a double for fear of not being able to climb some hills. The compact
I am looking at is the FSA Energy. It takes 110 BCD rings. The Double
takes 130 BCD rings. I figure a compact gives me more ring configuration
options including really close to the same gear ratio as the standard
double.

You can get *exactly* the same, not simply "close" if that's what you want.
There are more options with the 110, should you decide to try something else.
Primarily, the difference between the 110 and the 130 is the lower available low
(again, about 1.5 gear steps lower). Other than that, I don't think there is a
sharp difference.

Quoted message said:

The standard double will not let you get rings much smaller
because of the bolt spacing. Is a compact a good solution or would a
triple be better.

Really, it is whatever works for you. Triples have some good points too.
But... they cost a bit more, weigh a bit more, and have a necessarily higher
Q-factor. Doubles have the binary shift advantage if you use friction for the
front. If you have indexed front, then you probably won't care about the binary
advantage, since indexing washes it out.

On 10 Nov 2004 10:32:21 -0800, [email hidden] (Donald

Gillies) said:

Terry Morse said:

Wasatch5k wrote:

Quoted message said:

Quoted message said:

Double tooth count- 53/39
Compact tooth count- 50/34

How big of a difference with the 3 or 4 tooth difference make?

Quoted message said:

The difference between a 39 and a 34 is significant. Some folks in
the local club have compacts on their climbing bikes. They stand a
lot less than when on their standard bikes.

When your cadence dips below about 70 rpm, your muscles are using pre-
stored glycogen (fast-burning body sugars.) There is only a 10-minute
supply that is stored in the muscles of the body. These "fast burn"
carbohydrates cannot be easily replenished during a bike ride.

When you can climb at a higher cadence like 90, 100, or 110 rpm, you
can use glucose, and your body has 2 hrs of this fuel before it needs
to be replenished. More importantly, it can easily be replenished
during a ride by eating bananas or by consuming energy drinks. This
is why a marathon is a 2-hr race and this is why tour-de-france riders
eat continually during their races.

Therefore, with a compact crankset or a triple, you will likely to be
able to climb all day long, no matter what your fitness level. With
the steeper 39/53T crankset, you will likely be limited to 10 minutes
a day of intense climbing.

- Don Gillies
San Diego, CA

Dear Donald,

A smaller front chain ring may encourage a higher cadence,
but dropping from 39 to 34 teeth won't raise many all-day
climbing cadences from less than 70 to 90-110 rpm.

For the same speed, dropping from 39 teeth to 34 teeth
raises a 70 rpm cadence to only about 80 rpm (70 x 39/34)

For example, at 12 mph on a 2124mm circumference 700c tire,
a 39 x 18 spins at 70 rpm, while a 34 x 18 spins at 80 rpm.

At 9 mph, a 39 x 24 spins at 70 rpm, while a 34 x 24 spins
at 80 rpm.

At 6 mph, a 39 x 34 spins at 66 rpm, while a 34 x 34 spins
at 76 rpm.

The 34-tooth ring spins faster, but without larger rear
cogs, it spins only about 15% faster.

Raising 70 rpm to 90 rpm takes a 28% increase, dropping from
a 39-tooth sprocket to roughly a 30-tooth.

Raising 70 rpm to 100 rpm takes a 43% increase, dropping
from a 39-tooth sprocket to about a 27-tooth.

And raising 70 rpm to 110 rpm takes a 57% increase, which
would require trading a 39-tooth front ring for a 25-tooth.

Carl Fogel

Quoted message said:

A smaller front chain ring may encourage a higher cadence,
but dropping from 39 to 34 teeth won't raise many all-day
climbing cadences from less than 70 to 90-110 rpm.

Except nobody climbs with that high a cadence. 85 seems to be the
high end for steady state climbing.
--
terry morse Palo Alto, CA http://bike.terrymorse.com/

Terry Morse said:

Quoted message said:

A smaller front chain ring may encourage a higher cadence,
but dropping from 39 to 34 teeth won't raise many all-day
climbing cadences from less than 70 to 90-110 rpm.

Except nobody climbs with that high a cadence. 85 seems to be the
high end for steady state climbing.

Dear Terry,

I think that you're replying to Donald, who was the one who
suggested the beneifits of a rise from 70 to 90-110 rpm in
connection with smaller front chain rings.

Me, I chug along at a glacial 50-66 rpm in a 53 x 11 on the
flats, rising to what my spreadsheet suggests is a sizzling
68 rpm while climbing a 400-foot ridge.

No wonder the Fury RoadMaster's impressively compact 48 x 14
gearing leaves me breathless. With its smaller new 1975 mm
slicks, I'm spinning at a frantic 80-95 rpm.

Carl Fogel

My wife and I cycled in Europe this summer, including Alpe d'Huez. We
had both been riding 53/39 with 12/25 and 13/29 respectively. Seattle
is hilly but not the Alps. We both wanted lower gears for the trip. I
went with an FSA compact 50/34 with 12/25 and 12/27; she went with a
triple.

The gears were plenty low enough for both of us. She really did not
like the triple though. She found it finicky and not as second nature
as the double she was used to, so she has since switched to the same
FSA 50/34.

We went back to France in September and cycled in Provence for a week,
including Mont Ventoux. She loved the compact.

We like it so much, we just kept it on our bikes instead of switching
back to the 53/39.

I put on a Campy Centaur triple last Spring in preparation for some
riding in Northern Georgia. If I had it to do all over again, I would
do the same thing. I needed the 30 X 26. Campy's front Ergo shifter
allows you to trim the front derailer (Sheldon Brown spelling)
precisely.

[censored] Durbin

Wasatch5k <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Double tooth count- 53/39
Compact tooth count- 50/34

How big of a difference with the 3 or 4 tooth difference make? I live in
the rockies and tend to climb a lot of canyons. I'm a little timid to
get a double for fear of not being able to climb some hills. The compact
I am looking at is the FSA Energy. It takes 110 BCD rings. The Double
takes 130 BCD rings. I figure a compact gives me more ring configuration
options including really close to the same gear ratio as the standard
double. The standard double will not let you get rings much smaller
because of the bolt spacing. Is a compact a good solution or would a
triple be better.

I have many bikes. One of them has an Ultegra triple 52/42/28 (I
swapped the 30 for a 28) and a 13-34 9 speed cassettes
(13-14-15-17-20-23-26-30-34). That is, I have tightly spaced cogs at
one end and widely spaced cogs at the other. Th intention was that
when I was on the flats I could enjoy the tightly spaced gears. But I
find that on the flats I am usually in the 17-20 area.

Another bike has a Dura Ace 53-39 double. With the same cassette on
this bike it works out better but I am still not using the 13-14 too
much.

A third bike has a 110 bcd double. With a 36 tooth chainring I get
what I want out of this cassette. On the flats I am constantly
spinning in the 13-15 range.

If I had to do it over again I would have outfitted my triple bike
with a compact 26-36-48 triple.

Another advantage (to me) of the 110 is the assortment of gearing
available. I have 34, 36, 40, 42, 44, and 52 tooth 110 bcd chainrings
and I am constantly swapping things around.

Speaking only from my own experience,
Tom