I reckon it's going to increase the bending moment on the head tube by about 6 and a bit percent. So I'm not too worried about the head tube breaking off - I'd hope someone 6 and a bit percent heavier than me could ride it OK.
What are people's thoughts on the handling effect of it? I reckon 1.8 degrees difference (ignoring extra sag), which I don't think I'll waste sleep on. Should I waste sleep on it? 66 and a bit degrees is pretty slack for a 29er, and the BB will be a bit higher...
Basically I fancy a set of Yaris, it's over £100 more for the 120mm travel than the 150mm ones, and as far as I can see no replacement air shafts are available yet to put them down to 120mm. I don't think I'll mind the extra travel, except perhaps the increased height of the bars (better budget for some flat bars I guess). The 150mm ones might be more versatile if I get a new frame at some point in the future, too.
Go for it.... If you don't like it i'll try them on mine 🙂
Both X Fusion Slide with 32mm stanchions and Trace with 34mm can be bought new quote cheaply off eBay
Got mine lowered to 120 by 18 bikes.
Trace are great forks if you weigh a bit more or are an aggressive rider.
Couldn't tell you for definite, but the last bike I had designed around a certain fork length felt like an absolute pig with a fork 20mm too long fitted. Completely threw the geometry off, and wouldn't steer properly. It's not all about HA's!
I know it's not quite the same but my 650b Parkwood feels great with 140mm X Fusion forks in it. I may try the 150mm Pike from my fs just to see what it's like.