Crank with lowest Q-factor?
James Wagner
Does anyone have an idea of which crankset/bottom bracket produces the
narrowest profile measured between the outside crank surfaces at the
pedal hole? A few years ago when I was in the market for a new
crankset, I measured all of Shimano's groups and Campy's Veloce and
Athena group. I ended up buying the Dura Ace low profile crankset which
measured to be the narrowest, but I never got used to it. I had been
using an Ultegra crank with a Shimano 107mm BB and that produced the
narrowest profile though the chainline became a bit skewed. Usable
enough. Anyone have any ideas about the new Dura Ace and Ultegra groups
or the Record or Chorus groups(or any others for that matter)?
James Wagner
Baird Webel
I believe the Ritchey has a very low Q-factor, but I haven't measured
it.
baird
James Wagner <alp...@cpcug.org> wrote in article
<34CFA9DE...@cpcug.org>...
Doug
In article <34CFA9DE...@cpcug.org> James Wagner, alp...@cpcug.org
writes:
>(or any others for that matter)?
( 1-800-627-6664) and see if they can give you the Q.
Hans-Joachim Zierke
James Wagner schrieb:
> Does anyone have an idea of which crankset/bottom bracket produces the
> narrowest profile measured between the outside crank surfaces at the
> pedal hole?
TA cyclotouriste.
hajo
Robert Perkins
Do they use a 110/74 mm bolt circle?
Are they cold-forged or melt-forged?
I'm considering new cranks, and the Ritchey/Sugino cranks
have the lowest Q-factor I've seen in a cold-forged 110/74 crank.
Rob
Mark A
In article <34D05E...@nortel.ca>
Robert Perkins <no_spam_...@nortel.ca> writes:
> Are they cold-forged or melt-forged?
Melt forged? Next thing ya know they'll be coming out with "CNC
forged" cranks. ;-)
Hans-Joachim Zierke
Robert Perkins schrieb:
> > TA cyclotouriste.
>
> Do they use a 110/74 mm bolt circle?
When the TA Cyclotouriste was developed, propably in the 1950s, such a
recent development like 110/74 did not exist.
> Are they cold-forged or melt-forged?
AFAIK cold-forged.
> I'm considering new cranks, and the Ritchey/Sugino cranks
> have the lowest Q-factor I've seen in a cold-forged 110/74 crank.
Including Stronglight? I do not know about the Q-Factor of recent models.
On the other hand, I do agree that the Ritchey/Sugino cranks are among the
best made.
hajo
--
"Diesen URL gibt es nicht auf diesem System."
Antwort von www.bundeswehr.de auf "Suche: SFOR"
tabula
Mark A (Lo...@the.sig) wrote:
: Melt forged? Next thing ya know they'll be coming out with "CNC
: forged" cranks. ;-)
How 'bout CNC'ed forged cranks?
http://www.raceface.com/components/techinfo.html
Helps sell cranks, I'm sure.
-Ray
tab...@speakeasy.org
http://www.speakeasy.org/~tabula
Hans-Joachim Zierke
Mark A schrieb:
> Melt forged? Next thing ya know they'll be coming out with "CNC
> forged" cranks. ;-)
If you forge first, then CNC, the crank might even be usable!
hajo
Henrik Münster
Hans-Joachim Zierke <spam...@quijote.Huellhorst.Zierke.com> wrote:
> Robert Perkins schrieb:
>
> > > TA cyclotouriste.
> >
> > Do they use a 110/74 mm bolt circle?
>
> When the TA Cyclotouriste was developed, propably in the 1950s, such a
> recent development like 110/74 did not exist.
Does TA really still exist? Do they make other things? Where can
I get some info?
--
__o Med venlig hilsen
-\<, Henrik Münster
(_)/(_) <http://home4.inet.tele.dk/munster/>
Hans-Joachim Zierke
Henrik Münster schrieb:
> Does TA really still exist? Do they make other things? Where can
> I get some info?
They make all sorts of 7075 chainwheels, from Suntour Microdrive to Campy,
a nice modern road crank, a nice modern MTB crank, and sure they make these
modern cranks in lengths from 150 to 185 mm.
But you will have expected THAT.
Info? I always ask Hanrahan in Augsburg, they ask TA, since I do not speak
French. AFAIK, there is no DK importer. They sit in Clamart, F.
hajo
Robert Perkins
> Does TA really still exist? Do they make other things? Where can
> I get some info?
>
The Bicycles Raeder AG print catalog has a good selection.
http://www.bicycles.de
THolland63
To get the lowest Q-factor, the crank should be slim, straight and
perpendicular to the BB between the large chainring and pedal eye, and must end
up close to the chainstays (with proper chainline). Note that none of those
criteria deal with "low profile," which allows cranks to use a shorter BB, but
often splays the arms outward.
Minimum Q is determined by clearances from the chainstays and front derailleur.
In general, modern cranks are designed for more clearance for a variety of
seatstays. I have a TA Cyclotouriste on a Klein, and I had to chamfer the ends
so they wouldn't strike the stays. Don't underestimate the importance of
derailleur clearance -- it can create a notch in the crankarm where I've seen
them break.
TA - straight, slim, forged. Nice units with a low Q, it's just getting awful
tough to find rings for them, I've about done in my 54 . . .
TRH
THoll...@A0L.com (change A0L to AOL)
Bruce Frech
Q factor is determined by chainstay width where the cranks clear plus
crank arm thickness at the pedal hole. You can take any crank and use
shorter BB axles to reduce the Q factor until the cranks hit the
chainstays.
One side-effect is you also change the chainline - the distance from the
center of the bike to the center of the chainrings. This should be
around 44mm for road cranks. To keep that dimension and minimize Q
factor the crankarm must minimize the distance between the outer ring
and the arm. Straight cranks (old style) have about the same clearance
as low profile cranks since most of the change in shape is not near the
area which determines clearance. Low profile cranks add clearance for
your ankles which is different from Q factor.
Note that chainline does not match the center of the cluster, so that
dimension is already off from ideal (assuming you use all the gears the
same amount. who does?!). And MTBs with 135 mm hub widths are worse
than road bikes, but then they typically use the lower gears resulting
in less chain deflection.
So... get the crank with enough ankle clearance and then match the BB
to minimize Q while maintiaing enough chainline for your needs. Good
luck. If needed get a frame with narrower chainstays and use only the
inner cogs (the bigger ones) or live with misaligned chain.
-Bruce
James Wagner wrote:
>
> Does anyone have an idea of which crankset/bottom bracket produces the
> narrowest profile measured between the outside crank surfaces at the
> pedal hole? A few years ago when I was in the market for a new
> crankset, I measured all of Shimano's groups and Campy's Veloce and
> Athena group. I ended up buying the Dura Ace low profile crankset which
> measured to be the narrowest, but I never got used to it. I had been
> using an Ultegra crank with a Shimano 107mm BB and that produced the
> narrowest profile though the chainline became a bit skewed. Usable
> enough. Anyone have any ideas about the new Dura Ace and Ultegra groups
> or the Record or Chorus groups(or any others for that matter)?
>
> James Wagner
--
============== One of "The People Behind MicroStation" ==============
Bruce Frech Phone: (610) 458-5000
Bentley Systems Fax: (610) 458-1060
690 Pennsylvania Drive
Exton, PA USA 19341-1136 Bruce...@bentley.com
=====================================================================
Hans-Joachim Zierke
THolland63 schrieb:
> Don't underestimate the importance of
> derailleur clearance -- it can create a notch in the crankarm where I've seen
> them break.
Yes.
> TA - straight, slim, forged. Nice units with a low Q, it's just getting awful
> tough to find rings for them, I've about done in my 54 . . .
Don't know about the website, but they have it in their printed catalog.
hajo
Hans-Joachim Zierke
Robert Perkins schrieb:
I think you remember wrong. Bicycles has a good selection of Stronglight.
hajo
tabula
Hans-Joachim Zierke (spam...@quijote.Huellhorst.Zierke.com) wrote:
:
: If you forge first, then CNC, the crank might even be usable!
RaceFace in Canada does exactly this. They have a blurb on their Web
site. www.raceface.com. Any better than other current construction
methods? Who knows?
-Ray
tab...@speakeasy.org
http://www.speakeasy.org/~tabula
Dave Blake
tab...@speakeasy.org carefully typed:
>Hans-Joachim Zierke (spam...@quijote.Huellhorst.Zierke.com) wrote:
>:
>: If you forge first, then CNC, the crank might even be usable!
>
>RaceFace in Canada does exactly this. They have a blurb on their Web
>site. www.raceface.com. Any better than other current construction
>methods? Who knows?
Usable cranks are made using virtually all standard construction
methods. Cold-forged, hot forged, CNC billet.
But not all cranks made in a certain way are equal. There
are good CNC cranks and crappy ones. The same can be said
of melt-forged cranks and cold-forged.
If you melt-forge and CNC the crank does it make it any
better than a simple melt-forged crank ? Ceteris paribus,
yes, but that is rarely the case.
--
Dave Blake
dbl...@phy.ucsf.edu
Hans-Joachim Zierke
tabula schrieb:
> RaceFace in Canada does exactly this. They have a blurb on their Web
> site. www.raceface.com. Any better than other current construction
> methods? Who knows?
Sure not. Any good manufacturer forges first, CNCs then, Campy, Shimano,
Sugino, TA... They CNC the axle hole after forging.
But in traditional engineering, the engineer gets fired if the crank form
has to be CNCed after that as well - good engineering has always meant to
minimize material use and tool costs, the crank should come out of the form
very close to "finished".
_IF_ people accept high tool costs for fashion reasons, bad engineering is
no problem.
hajo