To be honest the actual building is really quick and easy although I couldn't give you an exact number of hours, I bolted stuff on as it arrived in the mail

What took a long time was all the research. About 6 months of digging through every source of info. Mostly on the internet but also talking to bike shops, manufacturers, comparing design, etc. Quickly realised that 99% of bike shops have no idea what they're talking about beyond what's in the product brochures of what they sell. A lot of places have 'mechanics' that shouldn't be allowed within 100 feet of a bike. Very dissapointing. But when you find the other 1% treat them like gold