Shimano's 7710 model track crank uses the same splined attachment as found with their Octalink V1 9-speed road cranks. The photo above shows the Keirin certified "7710" splined bottom bracket model which is available only in English threading and uses a sealed cartridge bearing system with steel cups.
For those with Italian threaded bottom brackets, the alternate selection is the "7700" (same as road double) unit, which uses a combination of needle and ball bearings housed in alloy cups as depicted below. If you care, the 7700 unit is not NJS approved.
|Pictured below, the 7610 bottom bracket is the match for Shimano's previous generation track crank: the 7600 series with traditional square spindle tapers. Available in English or Italian threading (the English one is Keirin approved), it has a symmetrical 109 mm. spindle and sealed cartridge bearings.|