You said you're transitioning from a 29'er to the road bike. If you are keeping the 29'er, why not just move the pedals back and forth until you're ready to go fully clipless? You have the shoes and the pedals you're used to, so there won't be a major problem getting used to them. All you need is a $15.00 pedal wrench and the off-on process takes three minutes or less. Just be sure you have the correct wrench.