dura ace triple crank gearing question

How about a double that thinks like a triple. Ritchey, TA, and FSA
are all announcing compact doubles in the 50/34 size category. I
can't wait to try this combo after using both DA and Ultegra triples.
They work fine, but 12-25 or 12-27 in the rear with 50/34 up front
sounds like efficient fun to me.




"Me" wrote in message ...
Hi, I'm thinking about converting my road cranks

I mainly want a triple set up so that in the few hills I have (short and
sharp) I can spin rather than stand (my 35 year old knees!), but I also like
to put the hammer down on the flats when riding in a group and don't want to
be undergeared.

My question:

why does shimano offer ultegra in triple as 52/42/30t

but dura ace only in 53/39/30? campy record has a 52/42/30 combo as well
dont they?

does any one find that having a 39 middle ring with say a 12-23 seem to be
too easy to spin out on the flats?

I love the fact the road compact, aka touring or mtb standard, crank is
becoming popular but want to say to everybody you know it is not a new
thing. A few intelligently spec'ed cross bikes for the last few years used
110 or 110/74 cranks. What about the first generation RSX stuff?



"eflayer2" wrote in message
om...
How about a double that thinks like a triple. Ritchey, TA, and FSA
are all announcing compact doubles in the 50/34 size category. I
can't wait to try this combo after using both DA and Ultegra triples.
They work fine, but 12-25 or 12-27 in the rear with 50/34 up front
sounds like efficient fun to me.




"Me" wrote in message
...
Hi, I'm thinking about converting my road cranks

I mainly want a triple set up so that in the few hills I have (short and
sharp) I can spin rather than stand (my 35 year old knees!), but I also
like
to put the hammer down on the flats when riding in a group and don't
want to
be undergeared.

My question:

why does shimano offer ultegra in triple as 52/42/30t

but dura ace only in 53/39/30? campy record has a 52/42/30 combo as well
dont they?

does any one find that having a 39 middle ring with say a 12-23 seem to
be
too easy to spin out on the flats?

The Ultegra is a very much better design, and you can replace the silly
30 tooth ring with something more reasonable. We commonly swap these
out for 26 or even 24 tooth rings.

This lets you use a tight cluster in back, and still have a decent
climbing gear.

Sheldon "Most Expensive Isn't Always Best" Brown

Are there problems with the Ultegra triple front derailleur using 26 or 24
tooth chainrings if you only change the small ring, and keep the 42 and 52?

L. D. Lide

I wrote:

The Ultegra is a very much better design, and you can replace the silly
30 tooth ring with something more reasonable. We commonly swap these
out for 26 or even 24 tooth rings.

This lets you use a tight cluster in back, and still have a decent
climbing gear.

Sheldon "Most Expensive Isn't Always Best" Brown

L. D. Lide asked:

Are there problems with the Ultegra triple front derailleur using 26 or 24
tooth chainrings if you only change the small ring, and keep the 42 and 52?

If you go with a 24, it's usually a good idea to add a $12 chain
deflector, such as a Chain Watcher or Jump Stop.

See: http://www.sheldonbrown.com/harris/d...tml#deflectors

This isn't normally needed with a 26. Upshifting to the 42 requires a
wee bit more skill than with the stock setup. You need to be prepared
for the cranks to suddenly slow down when the chain engages the 42.
It's not difficult, and not nearly as hard as shifting, say, a '90s bike.

Sheldon "Gears" Brown
+----------------------------------------+
| When I am grown to man's estate |
| I shall be very proud and great, |
| And tell the other girls and boys |
| Not to meddle with my toys. |
| -R. L. Stevenson |
+----------------------------------------+
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

"eflayer2" wrote in message
om...

How about a double that thinks like a triple. Ritchey, TA, and FSA
are all announcing compact doubles in the 50/34 size category. I
can't wait to try this combo after using both DA and Ultegra triples.
They work fine, but 12-25 or 12-27 in the rear with 50/34 up front
sounds like efficient fun to me.

I'd rather have (and I do have) the triple. But the wide-doubles are a great
solution when you need the range, but you're stuck with a double STI front
shifter. The cost of upgrading an STI system to a triple can be prohibitive. A
wide-double crank accomplishes the same thing, at much lower cost.

The triple is ultimately better -- smaller gaps, and better chainlines. I'm
glad I have the triple, but I'd be happy either way.

Matt O.

"rosco" wrote in message
ink.net...

What do you mean by a optimized triple rather than a double + granny? I ask
because I've only used doubles on road bikes, and as I age I'm considering
going with a triple on my next road setup. My natural inclination is to
think about a triple as a double with a bail-out granny addition. With an
optimized triple do you think about your gearing in a different way?

First, as Peter suggested, chainline is better overall. The 42T ring is more
universal than a 39, and since it's in the middle you get a good chainline
across the whole cassette. For lower or higher gears, the inner and outer rings
are better aligned with their corresponding cogs.

As I just mentioned, the gaps in the front shifts are smaller, so you can use
them more freely -- an upshift won't stall your cadence. You can use the rear
for little shifts, and the front for bigger ones. Having a smaller gap between
the middle and big rings seems more useful than between the small and middle.

The other triple I thought was interesting is the more difficult to find
(but apparently available) Campy 50-40-30.

That would be a good choice, if it has the range you need. A 50/12 is plenty
tall for me, and a 30/25 low enough. YMMV.

To Sheldon's point, a third
party chainring could always be substituted for the 30 to make a more
effective granny and still stay close to the 23 tooth max differential for
the front.

Most people would probably benefit from that. My stock Ultegra is fine for me,
but for an extra long ride or carrying some baggage I'd probably go a little
lower. Again, YMMV.

Sheldon seems to think stock triples are overgeared, and he's probably right.
Most higher-end bikes probably *are* overgeared for most people. Bike makers
sell us racer image and racer gearing, whether it's suitable for us or not.

Matt O.

Thank you for the detailed explanation. It makes perfect sense. A LBS is
trying to locate one of these Campy 50-40-30s for me (with some trouble),
and the owner of the shop was trying to convince me that I might spin-out if
I only get a 50 big ring. I wish I was that fast and strong. A 50-12 @90
rpm cadence equates to 29.6 mph while a 52-12 @90 rpm gives you 30.8 mph. I
could live with the 50 just fine, and if I ever need that extra speed, I'll
just pedal faster.


"Matt O'Toole" wrote in message
...

"rosco" wrote in message
ink.net...

What do you mean by a optimized triple rather than a double + granny? I
ask
because I've only used doubles on road bikes, and as I age I'm
considering
going with a triple on my next road setup. My natural inclination is to
think about a triple as a double with a bail-out granny addition. With
an
optimized triple do you think about your gearing in a different way?

First, as Peter suggested, chainline is better overall. The 42T ring is
more
universal than a 39, and since it's in the middle you get a good chainline
across the whole cassette. For lower or higher gears, the inner and outer
rings
are better aligned with their corresponding cogs.

As I just mentioned, the gaps in the front shifts are smaller, so you can
use
them more freely -- an upshift won't stall your cadence. You can use the
rear
for little shifts, and the front for bigger ones. Having a smaller gap
between
the middle and big rings seems more useful than between the small and
middle.

The other triple I thought was interesting is the more difficult to find
(but apparently available) Campy 50-40-30.

That would be a good choice, if it has the range you need. A 50/12 is
plenty
tall for me, and a 30/25 low enough. YMMV.

To Sheldon's point, a third
party chainring could always be substituted for the 30 to make a more
effective granny and still stay close to the 23 tooth max differential
for
the front.

Most people would probably benefit from that. My stock Ultegra is fine
for me,
but for an extra long ride or carrying some baggage I'd probably go a
little
lower. Again, YMMV.

Sheldon seems to think stock triples are overgeared, and he's probably
right.
Most higher-end bikes probably *are* overgeared for most people. Bike
makers
sell us racer image and racer gearing, whether it's suitable for us or
not.

Matt O.

"rosco" wrote in message
ink.net...
Thank you for the detailed explanation. It makes perfect sense. A LBS is
trying to locate one of these Campy 50-40-30s for me (with some trouble),
and the owner of the shop was trying to convince me that I might spin-out
if
I only get a 50 big ring. I wish I was that fast and strong. A 50-12 @90
rpm cadence equates to 29.6 mph while a 52-12 @90 rpm gives you 30.8 mph.
I
could live with the 50 just fine, and if I ever need that extra speed,
I'll
just pedal faster.


Agree, a 50t big chainring is more than enough for most riders. As for
finding a 50/40/30 triple, does your LBS do business with QBP? If so, its
listed in the QBP catalog, for example:

Centaur (polish):
http://aebike.com/site/page.cfm?PageID=30&SKU=CR9320

Centaur (Century-Gray):
http://aebike.com/site/page.cfm?PageID=30&SKU=CR9416

Record (polish)
http://aebike.com/site/page.cfm?PageID=30&SKU=CR9372

I'm sure Oschner has them too...

Capt Bike- You've made this assertion before, and I still don't get it. How
can
anybody make a "triple only" front shifter? BRBR
As far as I know, _all_ current Shimano front shifters (except Dura-Ace
10 sp) work with doubles or triples. BRBR

According to shimano's literature and from my experience, the DA for triple
front shifter will not shift a double shimano or any other front der...try
it...

..Capt I must admit I haven't tried using a Dura-Ace triple shifter on a
double
crankset (we hardly ever sell bikes with double cranksets) but I don't
see how it would be possible for any shifter to be able to work with
three rings, but not to work with two. BRBR


Due to the throw and trim clicks they install on it. It's like putting a triple
MTB front der with road triple shifters..The 'work around' is using a triple DA
front der with the double crank.

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

phausner- hopefully, someone will now write that the 9spd double da stis will
shift
triples and if thats the case I'll save myself $80! BRBR

Nope, the DA double is double only...

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