Speed is made out of power, mostly. The people who really train look at watts they can sustain per kg of body weight. So that's basically the same thing as fitness. A curly handlebar road bike can be a few mph faster by design but it's not the gearing that makes it that way. It's the aero posture, the weight, the skinny tires, some subtler things. You might be able to find a little more power in a lower gear / faster cadence, or just shifting more, or better position over the pedals, but it may not be a big change.
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Genesis 49:16-17