Comments on: Gear ratios http://mihai.ibanescu.net/gear-ratios Mihai's few cents Sun, 02 Oct 2011 17:24:20 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: Joseph Tate http://mihai.ibanescu.net/gear-ratios/comment-page-1#comment-163 Joseph Tate Sun, 07 Dec 2008 03:15:22 +0000 http://mihai.ibanescu.net/?p=62#comment-163 Two things: First, as Mr. Katz mentioned, to get a clean chain line, you really shouldn't use the the largest sprocket on the front and the largest on the back (i.e, 2:0), similarly for the smallest and the smallest (0:7). It puts too much strain on your derailleurs and chain. So a 24 speed is a misnomer. It's really more like an 18 or 20 speed. Typically the largest and smallest gears on the back have the same number of teeth whether you have 6, 7 or 8 sprockets, so it's really gradation between low and high that you get when you add sprockets. To trained riders, it probably matters. For amateurs, it's a way to get you to want to upgrade your gear, and reduce the integrity of the back wheel so you have to buy more of them when you hit that log or rock and bend your rims. Second, notice that the gear ratios overlap. When on a trail, where you really need to be able to shift gears quickly when moving from one terrain type to another, you pick the front sprocket for the trail you ride, and then you don't touch it. You use low for very hilly terrain, middle for a trail with some speed and not much climbing, and high for road riding. I'd love to show you a few trails. There's one at Lake Crabtree that's pretty good, some at Harris Lake, Falls Lake, and several other places in the Triangle. It's a lot of fun, and very different from road biking. Two things: First, as Mr. Katz mentioned, to get a clean chain line, you really shouldn’t use the the largest sprocket on the front and the largest on the back (i.e, 2:0), similarly for the smallest and the smallest (0:7). It puts too much strain on your derailleurs and chain. So a 24 speed is a misnomer. It’s really more like an 18 or 20 speed. Typically the largest and smallest gears on the back have the same number of teeth whether you have 6, 7 or 8 sprockets, so it’s really gradation between low and high that you get when you add sprockets. To trained riders, it probably matters. For amateurs, it’s a way to get you to want to upgrade your gear, and reduce the integrity of the back wheel so you have to buy more of them when you hit that log or rock and bend your rims.

Second, notice that the gear ratios overlap. When on a trail, where you really need to be able to shift gears quickly when moving from one terrain type to another, you pick the front sprocket for the trail you ride, and then you don’t touch it. You use low for very hilly terrain, middle for a trail with some speed and not much climbing, and high for road riding.

I’d love to show you a few trails. There’s one at Lake Crabtree that’s pretty good, some at Harris Lake, Falls Lake, and several other places in the Triangle. It’s a lot of fun, and very different from road biking.

]]> By: Jeremy Katz http://mihai.ibanescu.net/gear-ratios/comment-page-1#comment-164 Jeremy Katz Sun, 07 Dec 2008 00:52:26 +0000 http://mihai.ibanescu.net/?p=62#comment-164 It all depends on the type of riding you're doing. If you're doing much hilly riding, having the low gears are nice for making it up a long climb. And similarly, high gears are good for going fast. That said, a triple crankset isn't inherently better than a double -- you can usually get similar gearing ratios with the double and then you get some advantage in terms of cleaner chainline. N.B. I'm pretty much entirely a road rider at this point. It all depends on the type of riding you’re doing. If you’re doing much hilly riding, having the low gears are nice for making it up a long climb. And similarly, high gears are good for going fast. That said, a triple crankset isn’t inherently better than a double — you can usually get similar gearing ratios with the double and then you get some advantage in terms of cleaner chainline.

N.B. I’m pretty much entirely a road rider at this point.

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