Concord is a bike brand that I believe started in the early 1970s and ended sometime in the 80s. The brand was owned by Columbus Cycle out of Columbus, OH and were originally imported from Japan. Kuwahara is the Japanese company I most see mentioned as the manufacturer for Concord. Sometime during the 80s they moved to made in Taiwan. During the 80s they had a full range of bikes, check out this early 70s Deluxe road bike:
Concord Deluxe
Nice mid-level road bike with lugged steel frame and Shimano Titleist GS rear deralleur, Shimano Dura-Ace brakes, Sugino crankset, Sakae handlebars, and Araya wheels.
Concord Sport XT
I believe this model to be from the late 80s.
Here is the owner’s manual from Columbus Cycle that came with the Concord Sport XT:
Many thanks to Brian at Retro Glow Cycles for donating the Concord Sport images.
Models
Bentley – 5-speed cruiser
Black Max 24 – large BMX 24” wheels
Casper – kids 16” convertible bike
Champion – road bike
Cheerleader – girls Stingray style bike
Crusader – kids 20” convertible bike
Deluxe – mid-level road bike
Demon – BMX bike
Demon DX – competition BMX bike
Freedom – entry level road bike
Freedom Delux – mid-level road bike
Lil’ Casper – 12” kids bike
Mini Cross – 16” BMX kids bike
New Yorker – single speed coaster or 3-speed cruiser
Nitro – kids road bike 24”
Pacer – entry level road bike
Royale – mid-level road bike
Silver Bolt -competition BMX bike
Sport XT – entry level road bike
Trailmaster – mountain bike
Venture – mid-level road bike
Frugal Average Bicyclist 
An ancient Bike.
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Concord Bicycle! Very old!
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