Yes...9-10s cranks have the same space between rings...so you can convert. Another option to consider which is cheap...is lose the front derailleur completely...and LH shifter....or keep it as a brake lever and just don't run a cable to it. Run a single ring in front with outboard bash guard and inside chain retainer. I run 1 X 9 with 11-34 cassette on my 29er and honestly the bike is just about as fast as a std road bike with skinny tires. If you do a lot of climbing however...2 rings in front makes more sense if you must have short gear inches. I run a 38t front single ring on my middle position of triple SLX crank. The only reason why I don't run a 1 X 10 set up on my roadbike btw, isn't about the riding I do...1 X 10 would be fine. I run a compact in front so I can keep up with friends for the fastest gearing including descending. For just general flatish riding 1 X 9 is fine in my experience.