In reply to Lynsety:
For the rear rack the one thing to check is the location of disk brake; is the brake caliper mounted on the seat stay, or the chain stay? If its mounted on the seat stay, you need a 'disk specific' rack.
If your bike is the same model as the link below, then the brake is on the chain stay, and pretty much any rack should fit ok.
https://www.evanscycles.com/norco-threshold-a2-2015-cyclocross-bike-EV21181...
I've got a Pinnacle Arkose with is very similar, and I've used several generic racks without issue. They all fit in a similar way, bolt onto the two bosses at the top of the seat tube (via extendable metal straps on the rack), and the ones at the rear drop outs. They are usually supplied with relevant bolts, or the bolts will be already fitted to the bosses on your bike.
I think my current rack is a Blackburn Expedition, about 25 quid and bomb proof.