There is a fair bit of potential around Cusco I would say. I was there last year as part of a guided group with a company called Red Spokes.
Although I was on a mountain bike tour, the riding was largely on road sadly so I personally got a bit frustrated looking up at all these amazing hills and tracks etc and passing them by on roads while getting nearly killed by buses etc… 😥
Anyway, yes I would say there is definitely potential, it’s just finding it that’s the problem. Maybe talk to a couple of companies. Red Spokes may be able to put you in touch with Eduardo who led our group. Really cool bloke who seemed keen to do more actual mountain biking. He lives south of Lima though.
Brilliant country though… I’m sure you’d find lots of riding.
You could always pop down the road to Bolivia and do the Road of Death. It’s fun with stunning scenery but ultimately, still a road…
I’m not a roadie….can you tell?….. 😀