If it's a current model Inbred with extrawide bridgeless stays then, as Nuke says, you'll need a 50mm chainline to get anything like enough chainring clearance (IMO it's a real minus point for the On-One frames). The correct axle length for a 50mm chainline depends on the cranks. On my 853 Inbred with an XT Octalink crankset I need a 118mm axle but it can differ between cranksets (I'm fairly sure that there was an old LX chainset that needed a 121mm axle to give a 47.5mm chainline). Someone was asking about Deore square tapers a while and I think that they needed a shorter axle than their Octalink counterparts to give the same chainline. From the link that hopster has put up it looks like a 113mm axle will give a 50mm chainline but it might be worth checking with Middleburn in case your older model cranks were different.
