how low can I go?
04-17-16 | 05:07 PM
#1
Thread Starter
feros ferio
Joined: Jul 2000
Posts: 22,417
Likes: 1,880
From: www.ci.encinitas.ca.us
Bikes: 1959 Capo Modell Campagnolo; 1960 Capo Sieger (2); 1962 Carlton Franco Suisse; 1970 Peugeot UO-8; 1982 Bianchi Campione d'Italia; 1988 Schwinn Project KOM-10;
how low can I go?
This is aimed at Chas., or anyone else who wants to jump in.
My Capo Sieger has its original Campag. Gran Sport derailleur, and I have nice aluminum Simplex 49, 47, 46, and 45 (minimum size for the 3-to-6-bolt mounting adapters) tooth chainrings for the original Agrati cottered crankset. I have attached a photo to give an idea of the derailleur mounting tab length and rear derailleur orientation.
Option 1 (guaranteed to work): 49-45 / 14-17-20-24-26.
Option 2 (low gear - jockey pulley cram job): 49-45 / 14-17-20-24-28.
Option 3 (12-speed, using an ultra-6 freewheel): 49-46 / 14-16-18-21-24-26.
Option 4 (12-speed, lower bottom end, also ultra-6): 49-46 / 14-16-18-21-24-28.
Question 1: Will I be able to set the wheel position and chain length to make Option 2 work? This gives me about the same bottom gear as the 42/26 I run on the Bianchi and the Peugeot.
Question 2: Will the (option 3) ultra 6-speed work w/ this derailleur? I tried a test fit, and it looks like I need about 2mm of drive side spacing on the rear axle.
Question 3: How about going for the home run, with option 4? Now I am looking at both the 6 speeds and the 28T low gear cog.
My Capo Sieger has its original Campag. Gran Sport derailleur, and I have nice aluminum Simplex 49, 47, 46, and 45 (minimum size for the 3-to-6-bolt mounting adapters) tooth chainrings for the original Agrati cottered crankset. I have attached a photo to give an idea of the derailleur mounting tab length and rear derailleur orientation.
Option 1 (guaranteed to work): 49-45 / 14-17-20-24-26.
Option 2 (low gear - jockey pulley cram job): 49-45 / 14-17-20-24-28.
Option 3 (12-speed, using an ultra-6 freewheel): 49-46 / 14-16-18-21-24-26.
Option 4 (12-speed, lower bottom end, also ultra-6): 49-46 / 14-16-18-21-24-28.
Question 1: Will I be able to set the wheel position and chain length to make Option 2 work? This gives me about the same bottom gear as the 42/26 I run on the Bianchi and the Peugeot.
Question 2: Will the (option 3) ultra 6-speed work w/ this derailleur? I tried a test fit, and it looks like I need about 2mm of drive side spacing on the rear axle.
Question 3: How about going for the home run, with option 4? Now I am looking at both the 6 speeds and the 28T low gear cog.
__________________
"Far and away the best prize that life offers is the chance to work hard at work worth doing." --Theodore Roosevelt
Capo: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger (2), S/N 42624, 42597
Carlton: 1962 Franco Suisse, S/N K7911
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1982 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069
"Far and away the best prize that life offers is the chance to work hard at work worth doing." --Theodore Roosevelt
Capo: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger (2), S/N 42624, 42597
Carlton: 1962 Franco Suisse, S/N K7911
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1982 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069
04-17-16 | 07:06 PM
#2
Senior Member
Joined: Nov 2011
Posts: 7,955
Likes: 705
From: Port Angeles, WA
Bikes: A green one, "Ragleigh," or something.
Every RD hanger is a little different, and it might be comparing apples to potato skins, but my Nouvo Gran Sport derailleurs are shifting a 6-speed 14-30 cog set out back with a 52-40 up front, easy-peasy. Quite a bit more range than you're contemplating. Your option 4 Home Run sounds like a bloop single to me 
With a such a tiny jump between the the chainrings, I can't imagine any of your options not working, provided you're willing to mess with the chain length.
With a such a tiny jump between the the chainrings, I can't imagine any of your options not working, provided you're willing to mess with the chain length.
__________________
● 1971 Grandis SL ● 1972 Lambert Grand Prix frankenbike ● 1972 Raleigh Super Course fixie ● 1973 Nishiki Semi-Pro ● 1979 Motobecane Grand Jubile ●1980 Apollo "Legnano" ● 1984 Peugeot Vagabond ● 1985 Shogun Prairie Breaker ● 1986 Merckx Super Corsa ● 1987 Schwinn Tempo ● 1988 Schwinn Voyageur ● 1989 Bottechia Team ADR replica ● 1990 Cannondale ST600 ● 1993 Technium RT600 ● 1996 Kona Lava Dome ●
● 1971 Grandis SL ● 1972 Lambert Grand Prix frankenbike ● 1972 Raleigh Super Course fixie ● 1973 Nishiki Semi-Pro ● 1979 Motobecane Grand Jubile ●1980 Apollo "Legnano" ● 1984 Peugeot Vagabond ● 1985 Shogun Prairie Breaker ● 1986 Merckx Super Corsa ● 1987 Schwinn Tempo ● 1988 Schwinn Voyageur ● 1989 Bottechia Team ADR replica ● 1990 Cannondale ST600 ● 1993 Technium RT600 ● 1996 Kona Lava Dome ●
04-17-16 | 11:52 PM
#3
Not lost wanderer.
Joined: Jan 2013
Posts: 3,688
Likes: 1,434
From: Lancaster, Pa
Bikes: Cambodia bike,2012 Fuji Stratos...
the 28 option works better for both setups as it gives a good half step all the way to the end and doesn't have any duplicate ratios.
I used 28mm 622 because he dropped all 27/635 ERTO wheels
here is the layout of gears from the web, HTML5 Gear Calculator
I would go with the 49-46 six speed
I used 28mm 622 because he dropped all 27/635 ERTO wheels
here is the layout of gears from the web, HTML5 Gear Calculator
I would go with the 49-46 six speed
__________________
72 Geoffery Butler, 72 Gugificatizion Witcomb, 72 Raleigh Gran Sport SS, 74 Raleigh GrandPrix dingle speed, 74 Raleigh international, 81 Centurion Pro-Tour, 85 Gazelle Primeur, 29rBMX, Surley Steamroller 650b
72 Geoffery Butler, 72 Gugificatizion Witcomb, 72 Raleigh Gran Sport SS, 74 Raleigh GrandPrix dingle speed, 74 Raleigh international, 81 Centurion Pro-Tour, 85 Gazelle Primeur, 29rBMX, Surley Steamroller 650b
... whoa. Suddenly my "stick it on, see if it works" method doesn't seem so bad.
Thread
Thread Starter
Forum
Replies
Last Post
RhodeRunner
Bicycle Mechanics
15
06-24-14 05:33 AM
