So as I get ready to descend, the first thing on my mind is trying to decide how much harder gearing I need. Because this descent coming up I've ridden before and I know it's pretty short, and I start going uphill after it, I probably am only going to change gears in the rear. So, I'll shift down two or three gears for my climbing gear, just to have a little bit of extra purchase when I'm on the descents, to create some more speed, and take it from there. So, one, two, three, shifts, and boom, I'm there. If it was a considerably longer descent, where I knew I'd be descending for seven or eight minutes, I'd probably also take this now as an opportunity to shift into the bigger chain ring up front. Right side's the rear for both the brakes and the shifting, left side's the front, so I would shift myself into the harder chain ring up front. It's like, there's a two or three tooth difference between each cog in the back of your bike, there's a ten tooth difference in the front. So, depending on how much your speed is going to be changing, that's how you decide which gear to use. One nice thing about putting it into the bigger, harder gear up front is that it puts more tension on the chain, so it rattles around less when you're descending -- makes less of a clanking noise and everything like that as you can see here right now my bike is in the little chain ring, so there's a lot of potential for the chain flapping around, but as I put it into the larger chain ring, you'll see that there is considerably more tension on the chain. The chain's farther from the chain stays, less likely to slap around and everything like that, so you're more likely to have your chain when you get to the bottom of the descent, if you put it into a harder gear.
