Compact cranks and Q factor

Hallo. I write from Ravenna, Italy, I read this ng for its
interesting technical contents.

Quoted message said:

My questions are: does anyone know if FSA CFJ compact cranks have a Q
value nearer 147 mm,

[...]

Quoted message said:

Also, can I stick with a short rear mech even if I use a 12-25 with the
50/34 of the FSA chainrings?

I replaced few weeks ago an Ultegra 2003 crankset with a FSA Energy,
preserving Shimano Octalink BB I had. Q factor is the same (should be
143 mm, not 147, AFAIK), and I didn't noticed any difference with
Ultegra. Just climbing is easyer now :-)

12-25 should work very well with short-cage rear derailer, I have a
13-25 and works perfectly. I just replaced chain with a new one 2 links
shorter.

Unluckyly, it seems that octalink FSA crankset are out of order, so
probably you should replace also BB.
BTW, an FSA Gossamer Compact with MegaEXO BB is reasonably cheap and
should work for you.

Cheers.

--
Massimo Bacilieri AKA Crononauta
ICQ:4005815

Hi--
I was quite concerned about this when I switched a bike to compact from
Ultegra, especially as the main reason not to use a triple on a backup
bike is to maintain the same Q-factor.

As far as I recall, all the FSA doubles were at 147mm, which is exactly
the Ultegra (and probably all other Shimano road groups) standard.

The Q-factor feels exactly the same on my Gossamer compact as it does
on my Ultegra double.

BTW, they are great, and everyone should use them. I have an XT
long-cage rear derailleur hooked up to my ultegra shifter, so it's
50x34 in the front and 11-32 in the back. I'd ideally like to compact
the rear cluster a bit, a 13-14-15-16-18-21-24-28-32 instead of the
11-12-14-16... that is standard XT. Range _greater_ than a standard
triple, with superior front DR performance and narrower Q-factor of a
double.

--Shayana kadidal

Quoted message said:

My questions are: does anyone know if FSA CFJ compact cranks have a Q
value nearer 147 mm, or are there any other reasonably priced compacts
out there that would do the job? Note that due to being fairly long
legged I really need 175 mm cranks. I can't find any info on FSAs
website on CFJ cranks.

Also, can I stick with a short rear mech even if I use a 12-25 with the
50/34 of the FSA chainrings?

Look for an old crankset 110 like a Sugino V/P, G/P, AT, or Mighty
Tour. They use a 113 bb as a compact double. The Q is very narrow.
I know, because I switched from my Mighty Tour to FSA compact, I could
feel the difference. BTW, I prefer wide Q. FSA chainrings are great.
You can get their twins on a set of Nashbar compact cranks and throw
the arms away. The Nashbar ones say 'RPM' instead of "FSA". If you
are looking at the reverse side of the ring, you can''t tell the
difference. Booth 7000 series aluminum.

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In article <[email hidden]>,

Quoted message said:

I want to replace my standard road double Shimano 105 crankset (52/42)
with a compact for light touring. I have tried the Stronglight Impact
compact double but the Q factor is 11 mm greater (158 mm, previously
147) than my old 105s and this causes real pain in my left knee. Both
LH and RH Stronglight cranks curve out further than the 105s and
neither crank goes on the 107 mm Shimano UN71 BB as far as the old
ones, exacerbating the problem.

_ You might just need a different BB. It sounds like the Impact
cranks need a Campy or ISO taper. Measure the chainline on your
current setup, if it's not somewhere near 43mm, then you might
be able to solve the problem with the correct BB.

http://www.sheldonbrown.com/gloss_ca-m.html

_ Phil Wood makes ISO taper BBS in 102 and 110 widths.

_ Booker C. Bense

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