I'm a mountain biker, but about to purchase my first drop bar road bike. Last time I rode a drop bar bike was when I was a kid in the 70's. I'm using my hybrid more than ever to go on long road rides, so figured it's time to try a full road bike.

I tried clipless pedals with my mountain bike in the past. I hated them. My problem is forgetting to clip out while I rode my bike on the street. Took a couple of falls. And on the trails, I just couldn't get rid of the fear of being locked in during a downhill or uphill single track next to a large drop-off. So I went back to flat pedals after a couple of weeks.

I imagine it's easier on the street (if I can remember to clip out). So I'm gonna try it again (last time was years ago on the mountain bike). I have found roads without that go 7+ miles without a stop sign or traffic lights. This would probably work great with clipless (for someone getting used to them).

First, I see "road" pedals and "mountain" pedals. What's the difference? And I see the Shimano 105 PD-5800 pedals on sale for $73 and the Shimano PD-A520 on sale for $20. Other than the weight, what's the difference and which would be better for a newbie?

Thanks for any advice.