The spec list i was able to find on line (no thanks to the OP for letting us know what brand of bike we're talking about) doesn't list the BB size. only that it's a tapered square in a 68mm shell. There's a good chance that the spindle length is about 103mm as this is a common size for track cranks these days. With this assumption you can search for cranks that are suggested to be used with this spindle length and style. But until you actually fit the new cranks to the bike it's hard to be certain if the current BB will work/position things well. Andy.