Shimano 105 Crankset FC-1050 170mm Double 53/39. Good used condition. Chainrings are non-biopace. From velobase.com: Introduced in 1987 (first appearing in August 1986 Catalog for the 1987
Year) Shimano 105 would introduce alot of new technologies that year.
that would not be seen on Shimano 600 for another year. Technologies
such as SLR (Shimano Linear Response) Brake systems in 1989 The grouppo
was updated for 7 speed and it was replaced by the 105SC group in 1990. Chainring Count Double BCD 130mm BB Style Square Taper (JIS) Pedal Threads 9/16" x 20 (English) BB Length 113mm (BSC), 115mm (Italian) Flutes None Length 170 Arm/Spider Material Aluminum Alloy Front Markings Shimano 105 Back Markings FC-1050 [length] Extractor Threading 22x1mm (Standard)