Compact Crank Compatibility Questions

On Aug 3, 5:19*pm, RS wrote:
In article ,
says...



Thanks for the replies. *One question, did you have to adjust the position
of the front derailleur downward on the seat tube? *I had heard this might
be necessary, but mine is a braze-on, so I wouldn't be able to.
"RS" wrote in message
...
In article ,
says...

I'm recovering from a hip replacement, and am considering changing to a
compact crankset to achieve some lower gearing on my Waterford. *My
current
set-up is a Dura-Ace 9-speed group, with a Truvativ Roleur GXP carbon
crankset (Gigapipe BB) and a SRAM chain. *I'm looking to get another
carbon
crank, and the one's that keep popping up are the Truvativ and FSA brands
(in a reasonable price range). *Any issues with compatibility that I need
to
be aware of? *Will my DA front derailleur handle the compact crank? *Any
suggestions for carbon compact cranksets that you're sure WILL or WILL
NOT
work would be appreciated ... it'll just make my search easier.

Thanks!

I use DA7700 shifters and a DA7700 front derailleur with an FSA Energy
ISIS
compact crank, the crank is not carbon (it was cheap on ebay, I went for
it, it
works fine). *I'm using a pretty wide range cassette in the rear 11-28 and
rarely
have problems shifting the front. *It does have to be adjusted correctly.
I had
tried the FSA compact specific front derailleur on essentially the same
setup on
another bike, same exact crank except Shimano BB type. *The derailleur
worked
no better than the standard DA front derailleur. * You should be fine.

There is some play minimal play allowable up or down, even with a braze-on. *
You'll have to lower it, try to get it 2mm-3mm above the large sprocket. *You
may have to experiment with the vertical distance a bit, as I recall I tried a very
close tolerance at first but found it shifted better leaving a bit more space. *I do
have a clamp-on so it was possible to get more vertical movement. *

Actually, closer that that because the 'arc of a 53/39 FD makes the
tail a little high so 1mm or so of clearance will ensure good FD
operation. Most frames with a brazeon tab will allow it to get low
enough(just did a cervelo) and if it doesn't file the slot to get it
lower.

In article
,
Qui si parla Campagnolo wrote:

On Aug 3, 9:29*am, Ryan Cousineau wrote:
In article ,

*"tlarwa" wrote:
I'm recovering from a hip replacement, and am considering changing to a
compact crankset to achieve some lower gearing on my Waterford. *My
current

This may help: I have a Truvativ Rouleur GXP carbon compact crank on my
cyclocross bike. Using a Shimano 9 drivetrain (Tiagra shifter up front?
It was what I had in The Pile) it works acceptably well, though I'd
recommend a chain watcher.

If it was me, I'd just use your current front derailer. If it's too
crappy, then Shimano makes a compact-specific fder.

Actually, shimano doesn't make a compact FD. When some shimano setups
started coming on Treks, they used a 50/36 combo, now a 50/34 combo
but shimano never had a compact specific FD, don't need one, BTW.

That's right, Shimano made a big deal about how their special rings
didn't need a special derailer.

For the record, my compact crank is shifted by a bog-standard Tiagra
fder.

--
Ryan Cousineau http://www.wiredcola.com/
"In other newsgroups, they killfile trolls."
"In rec.bicycles.racing, we coach them."

On Aug 6, 4:44*am, Qui si parla Campagnolo wrote:
On Aug 3, 8:02*am, "tlarwa" wrote:

I'm recovering from a hip replacement, and am considering changing to a
compact crankset to achieve some lower gearing on my Waterford. *My current
set-up is a Dura-Ace 9-speed group, with a Truvativ Roleur GXP carbon
crankset (Gigapipe BB) and a SRAM chain. *I'm looking to get another carbon
crank, and the one's that keep popping up are the Truvativ and FSA brands
(in a reasonable price range). *Any issues with compatibility that I need to
be aware of? *Will my DA front derailleur handle the compact crank? *Any
suggestions for carbon compact cranksets that you're sure WILL or WILL NOT
work would be appreciated ... it'll just make my search easier.

Thanks!

Compact is a plug and play option. Lower your FD, perhaps take a link
out of your chain. In my experience, Truvativ(Sram) and FSA don't have
the best bearings and chainrings tho. I think a R600/700 shimano or
Campag compact would be a better choice. Both would work fine with
your setup.

Another option for crank is the Sugino Alpina/Cospea sold by VO:

http://www.velo-orange.com/sualcr.html

It takes a square taper bb, but the polish is fantastic and at $165,
very reasonably priced too! What's not to like?

In article ,
John Forrest Tomlinson wrote:

On Tue, 05 Aug 2008 22:11:39 -0400, Doug Taylor
wrote:

On Sun, 03 Aug 2008 21:26:41 -0400, "David L. Johnson"
wrote:

tlarwa wrote:
Thanks for the replies. One question, did you have to adjust the position
of the front derailleur downward on the seat tube? I had heard this might
be necessary, but mine is a braze-on, so I wouldn't be able to.

You should adjust the position of the front derailleur downward, so that
it is as close as can be to the big ring. It shifts better that way.

And yes you can adjust the derailleur height with a braze-on mount.
That bolt hole is slotted.

I'm not so sure. If the braze- on is designed for 53/39, and riveted
to the frame, it seems intuitive that the derailleur can't be mounted
low enough to achieve the "recommended" clearance on a 50 tooth ring.
This may or may not affect optimum shifting.

You've intuited it, and Johnson has reported (I believe) his
experience. Which should we follow?

I used a 50 tooth front chainring on a traditional racing bike with a
braze on and it worked fine for me. I just lowered the front
derailleur a bit within the braze on. Most or perhaps all front
derailleur braze ons allow some vertical adjustment.

Difference in radii of the chain rings is
[53/(2.pi) - 50/(2.pi)](1/2) inch = 0.24 inch = 6 mm.

--
Michael Press

On Wed, 6 Aug 2008 04:46:07 -0700 (PDT), Qui si parla Campagnolo
wrote:

Actually, shimano doesn't make a compact FD. When some shimano setups
started coming on Treks, they used a 50/36 combo, now a 50/34 combo
but shimano never had a compact specific FD, don't need one, BTW.

Actually, the Shimano DA 9sp/7700 seems to be the best shifting front
derailleur for the various compact cranks/rings. I don't know why.
The most problematical front derailleurs for me were the Campy CT.

In article ,
says...


On Wed, 6 Aug 2008 04:46:07 -0700 (PDT), Qui si parla Campagnolo
wrote:

Actually, shimano doesn't make a compact FD. When some shimano setups
started coming on Treks, they used a 50/36 combo, now a 50/34 combo
but shimano never had a compact specific FD, don't need one, BTW.

Actually, the Shimano DA 9sp/7700 seems to be the best shifting front
derailleur for the various compact cranks/rings. I don't know why.
The most problematical front derailleurs for me were the Campy CT.
Hmm, its what I'm using with a 50/34 cheapo FSA Energy ISIS compact and it
works fine.

On Aug 7, 5:09*pm, Paul Kopit wrote:

The most problematical front derailleurs for me were the Campy CT.

I'll agree with that. Had a Centaur model and it never worked well.
Finally put the regular double front derailleur back on.

On Aug 8, 7:55 am, "
wrote:
On Aug 7, 5:09 pm, Paul Kopit wrote:

The most problematical front derailleurs for me were the Campy CT.

I'll agree with that. Had a Centaur model and it never worked well.
Finally put the regular double front derailleur back on.

Really weird experience for me - I had a Veloce QS CT that I was using
with Veloce QS shifters (Escape mechanism) and It was the worst front
shifting I've ever experienced, period. I replaced both the shifters &
the FD with pre-QS Centaur, with a regular double FD, and that setup
works well.

However, I saw a NIB Record carbon QS CT on ebay for $40 and I
couldn't pass it up. I paired it with pre-QS Centaur levers on the
Schwinn I'm building up, and it shifts BEAUTIFULLY.

I have a feeling it's EXTREMELY sensitive to proper setup, and I
lucked out with a good height and angle on this one.