I need some replacement brake cables. The levers I have need an unusually large barrel on the end. The "normal" barrel end is too small. The cable is also quite large in diameter but that is not a necessity. The existing cables look almost as if they were intended for a motorcycle, that's how large they are. The levers are Shimano.

Does anyone stock these?

Should I go to a dirt bike shop (off-roading parts place)?