Would you for any reason desire to match a 5in 2010 or later trance x with a fork longer than 125mm? If you upped the travel to 140 or 150 you would raise the bars (compensate by slamming, no rise bar, small stem?) slacken the headangle by a degree or two and raise an already very low bb. The aim would be to make it a trail centre playbike; the travel adding confidence on the descents (which in Europe tend to be much less smooth and somewhat techy) and give you more bb space (avoiding the problem with bikes like the trance and, say trc, which is that in the UK you'd spend your entire life hitting shit on rocks). Thoughts?
Lots of people, including myself, run a 140mm fork on the trance. It works quite well and would do exactly what you are looking for. I believe 140mm is the max you can go without voiding the frame warranty and making it too big of a difference in travel. Hope that helps.
I run a 150mm revelation on mine and I love it. The only drawback is on really steep climbs sometimes the front end feels a little light - I am also running a really short stem so that is part too - but as far as descending goes it really changes the character of the bike and makes it a much more capable and aggressive ride.
i have 140mm but went for 2012 fox 36 float rlc fit (dropped to 140 mm ) for the extra strength up front, the trance can do a hell a lot more than people think