I’ve seen this mentioned a few times, do you have any more info or a previous thread on it?
It’s nothing too complicated – I’d just been busily designing a custom hardtail when the Zero AM was launched and realised that a -2 deg headset and shorter fork would make it near identical to what I wanted (but alloy, not steel). This was it when freshly built up with my parts:
Since then the cranks have changed from 175mm SLX to 165mm XT and the pedals to Vaults, I’ve raised the bars by 5mm and the saddle height’s gone up a fair bit. There’s a Works Component -2 deg headset in there and the fork is a 130mm Pike. The tweaks add about 10mm to the reach, take 10mm off the BB height, steepen the seat tube by 1.4 deg and slacken the head tube by 1.1 deg.
Bird offer up to -1.5 deg anglesets when you buy direct from them (I already had the Works one) and the Zero TR is longer in reach and chainstay if you want an even longer bike (the XL being 495mm and 440mm respectively). Nicely built frame, great value (especially if you need a full build) and a good platform for doing interesting hardtail things! Great service too.