A couple months ago I got a Giant Anthem 29er, which has a full XT group including a long-cage rear derailleur (non-Shadow), 11/36 cassette, and a 26/38 crankset. The lower climbing gears work well for me, but I'm finding myself pedaling around on the big ring a lot and I'm spun out at around 24-25 mph, so I keep wishing for more top speed. So the question is: Can I swap the 38t big ring for a 40t, or is that too big a jump for the front derailleur to shift well? (Or is there such thing as a 10-36 mtb cassette?) I've dug around the interwebs and asked one or two folks in bike shops, but I keep getting different answers. Can anyone point me to a definitive source on this, or better yet, have any of you actually done this exact change? Thanks in advance for your input!