||03-28-14 10:23 AM
Originally Posted by caloso
15" means 15 seconds. Sorry for the shorthand. Note that these will put a fair amount of stress on both the bike and the rider so make sure both are in good working order first.
I also neglected to mention that these are meant to be done out of the saddle and in the drops. If you don't have drop bars, just get as low as reasonably possible.
"...And oh how they danced
The little children of Stone'enge..."
I think you are having a Spinal Tap moment...unless you are really slow getting off the line. My grandmother was faster than fifteen inches
in 15 seconds...and she was using a stroller!;)
You are off on the distanced covered in 15 seconds. It would depend on the rate of acceleration and time. Consider: If you were crossing a 4 lane intersection, that's about 60ft. If the final speed is 15mph, the acceleration is 4 ft/sec and the distance is covered in 3.7 seconds. That's a leisurely pace. Assuming that you stop accelerating once you hit 15mph, in 15 seconds you will have reached 112 feet. If you accelerate at 7 ft/sec to 20 mph, you'd cover that distance in around 2 seconds and you'd have reached 150 feet in 15 seconds.
Originally Posted by cogdriven
You can do it that way on a geared bike, but that's not how most people accelerate with gears. On a single speed you are in that situation all the time and are going to be faster than you would be with gears. This is especially true on a fixed gear. You never spin out until you're going a lot faster than you'll get in an intersection. There is always resistance to your pedal stroke and you don't get that chain slap that you might expect if you tried this on a geared bike in too low a gear.
Don't take my word for it. See if you can borrow a fixie and try it yourself. The advantages really show in traffic, when you need to get from 20 to 30 ASAP.
mstraus has it right. A single speed bike has no advantages over a multigeared bike in terms of acceleration or speed. A single speed is limited to what speed you can get out of that single gear. Once the rider hits a maximum rpm at the cranks, they don't have any more ability to accelerate. On a geared bike, I can change gears and accelerate even further. I could do the same as you can on a single speed and not shift but why would I want to do that?