Bumps, Humps and Jumps
So you’ve made it this far, you know 1. that you love pump, 2. that you love tracks, and 3. when you put one and two put together it fits in your backyard.
As you begin the design stage consider what kind of bike you will be riding on the pump track. As you can see from the diagram below you don’t want to be stuck with rollers that are too big or too small for your bike.
*While the Penny Farthing does have the highest bottom bracket (because it has not bottom bracket) it is not recommended for pump tracks
Let’s break down our terminology before we continue. A bump is to small to use in a pump track, it just slows you down. Think of speed bumps, or as James May calls them “sleeping policemen”. Then there is the hump, also known as the roller. This is the most useful of the three, which you will use the majority of the time. A hump helps you gain speed while you “pump” off of it. Lastly is the jump, which is like a roller/hump but with a lip on the end of it. Observe the diagram below detailing the differences.
Still confused when you should use each of the three. Check out this diagram.
Now that that is squared away pull our you pencil and start drawing is hump and jumps (no bumps) that will help make your track faster, (or if you like start digging and if it doesn’t work move the dirt to the next hump attempt). A well designed track can be ridden without pedaling after the initial start. Here is what we did to gain the most speed from our track.
We determined that three rollers across the long straight would help us gain the majority of our speed with just a couple of extra humps through out to keep speed. The most important thing to consider when implementing a hump is the speed loss to awesomeness ratio.
As you can see the perfect speed loss to awesomeness ratio is 7.
Building the Dream
Your track is all designed now it is time to implement. Now lets lay down some ground rules before you start digging.
Rule #1 – Always add more dirt. Not sure if you hump is good enough? Add more dirt, just remember your speed loss to awesomeness ratio when deciding where to put the dirt. I know what you are thinking, but what if my yard is flat? I’ve got you covered.
Rule #2 – Make sure your significant other approves of your pump track plans. If they don’t wait until they are gone, rather to work or visiting family to implement your brilliant plan. Trust me they will love it once it’s in.
Tomorrow we will cover building and saftey on your pump track in Pt. 3. Until then enjoy this.