My inclination would be to just use a ready-built accelerometer IC. I'm a fan of buy over make, if the right thing is commercially available.
You know, you could experiment with an iPod or iPhone. Strap it to your bike and ride around with an app that gives access to the accelerometers. (I have fun with this free one, but I'm not sure it would suit your need.) Before long I think you'd get a good feel for the physics and numbers involved. Would be good for testing your prototype, too.
BTW, be careful to keep your eyes on the road, too.
You know, you could experiment with an iPod or iPhone. Strap it to your bike and ride around with an app that gives access to the accelerometers. (I have fun with this free one, but I'm not sure it would suit your need.) Before long I think you'd get a good feel for the physics and numbers involved. Would be good for testing your prototype, too.
BTW, be careful to keep your eyes on the road, too.