Diamond Back Large Pro Specifications
|Finish||Chrome (with blue components) or flamboyant red or blue (with gold components).|
|Frame||Diamond Back 4130 chrome-moly. ( Koizumi )|
|Fork||Diamond Back 4130 alloy. chrome-moly. Dual position (leading axle and centerline) dropouts. ( Koizumi )|
|Handlebars||Diamond Back chrome-moly, butterfly.|
|Grips||OGK, Mach model vinyl.|
|Stem||Diamond Back by Sugino, chrome-moly shaft and bolt, forged alloy head.|
|Rims||Araya 7C side-polished (on chrome bike); Araya 7X gold, no side-polish (on red or blue bike)|
|Brake calipers||Dia-Compe, front and rear.|
|Tires||Diamond Back Skinwall Knobbies (by IRC).|
|Pedals||Diamond Back BM10 (by MKS).|
|Cranks||Sugino, forged chrome-moly one-piece,175mm.|
|Front Sprocket||44T Sugino alloy, chrome spider.|
|Rear Sprocket||16T SunTour, easy-off freewheel.|
|Chain||1/8 inch, Chrome (HKK)|
|Seat||Diamond Back by Kashimax.|
|Seat Post||7/8″ Fluted aluminium alloy.|
|Seat Post Clamp||SunTour, aluminium alloy.|
Diamond Back Large Pro Frame and Forks
The large pro came in 2 colours and chrome. Described as flamboyant red and blue, the paint has a metallic finish to it. The large pro came with double drop-out forks which comprise of dropout that has a forward and centre position.
The centre position provide unpopular and was discontinued when the next generation of Diamond Back pro models, the Pro Kit, was brought out.
Large Pro Identifying characteristics
|Identifying characteristic||Looks like|
|Large gusset, diamond cutout|
|Serial numbers are found on the rear, non-drivemdropout and are in the Koizumi standard 6 digit format followed by a Kanji (baseball).|
Serial numbers will begin 9, 0 and 1. This means 1979, 1980, 1981
- Serial number are found on the rear, non-drive dropout and are in the Koizumi standard 6 digit format followed by a Kanji (baseball).
- Serial numbers will begin 9, 0 and 1 – 1979, 1980, 1981 only
- 1981 models will have a 1 followed by A, B or C, for January, February, March.
- By April 1981 the model was replaced with the Senior Pro.
- Original bikes came with double drop out forks, as seen above.
- See details on that page for more.
- Loop tail
- Large gusset (3 TIG welds)
- Model production run was from 1979 to April 1981
Serial number tools
Our serial number checker can identify most Japanese Diamond Back between 1979 and 1983. New bikes are being added regularly.