SunTour Grand-Prix (type 3)
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Category:  Rear Derailleurs
Name:  SunTour Grand-Prix (type 3)
Brand:  SunTour
Model:  2300
Years:  1964 - 1970
Country:  Japan
Weight:  303 grams (avg)
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Added By: Catnap on 05/12/11
Updated By: peterbman on 05/09/18
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SunTour Grand-Prix (type 3)SunTour Grand-Prix (type 3)SunTour Grand-Prix (type 3)SunTour Grand-Prix (type 3)
Outer Plate MarkingsSunTour Grand-PrixInner Plate MarkingsMAEDA IRONWORKS LTD. JAPAN
MaterialSteelDesign CategorySlant parallelogram
Attachment Bolt SizeCable Attachment Bolt Size
Shifting SystemsFrictionCable AdjusterNo
Cage LengthShortMax Cog Size28
Max Chain Wrap  
General Information

The Suntour Gran-Prix introduced the slant parallelogram to the world. It is the most famous of the many brain-children of Nobuo Ozaki, SunTour’s legendary chief designer. The idea is brilliantly simple - as the pulley cage moves inwards, it also moves downwards, following the shape of the freewheel and maintaining a reasonably constant chain gap. Virtually every modern derailleur of any quality uses this design. The 1964 patent on this design  (US patent # 3,364,762) allowed SunTour to gradually dominate the derailleur industry, until it ran out in 1984.

The SunTour Gran-Prix was also notable in a number of other ways: 

It fits a Campagnolo hanger (and has an adjustment screw) - starting the Japanese move away from Huret (SunTour’s original choice) and Simplex (Shimano’s original preference). The hanger plate on this example is particularly unusual with two holes for drop-out bolts - but it has the tell-tale Campagnolo tag position. The Gran-Prix is low-normal (‘Rapid Rise’ in Shimano-speak). And, in addition, it uses SunTour’s unique single spring design - the same spring operates the parallelogram and also tensions the chain. These last two features are a touch too mad for my tastes - and I have never found low normal gears to be very positive - whether they are the ancient, cheapo, SunTour Skitter or the ultra-modern, fantastically refined and expensive Shimano XTR.

Text from: http://www.disraeligears.co.uk/Site/SunTour_Gran-Prix_derailleur.html
Quality:Rarity:
 
 
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Brand Information(click to expand)

SunTour (Maeda)

SunTour derailleurs have a two-letter date code. On rear derailleurs the code is stamped on the back side of the inner parallel arm. On front derailleurs it is stamped on the back side of the inner cage.

The first letter represents the year. Larry Osborn and I believe O (Oh) is 1972, V is 1979 and A is 1984. As with Shimano, the second letter is the month code, where A is January and L is December.

SunTour Year Code

N
O
P
Q
R
S
T
U
V
W
X
Y
Z
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
 
A
B
C
D
E
F
G
H
I
1984
1985
1986
1987
1988
1989
1990
1991
1992

SunTour Month Code

A
B
C
D
E
F
G
H
I
J
K
L
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

The earliest Suntour derailleur I have found with a code is marked OF. A rear derailleur marked OD (corresponding to April of 72) was reported by Leighton Walter. I have a bike that dates from between 1970 to 1972 that has the original SunTour derailleurs. These derailleurs do not have date codes on them, so I believe the coding started sometime between 1970 and April of 1972.

(source: vintage-trek.com)

 
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WeightSourceNotesAdded By
289 GramsUnknown Catnap
317 GramsSpec peterbman
Spidel
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