Powerisers are a type of spring-loaded stilt that allow you to take 9ft strides and jump 6ft in the air. They were designed by Alexander Bock and the sport is usually known as bocking or power-bocking. The stilts are also known as PoweriZers, Power-Skips (The original design), 7 league boots, pro-jumps, or velocity stilts. I will refer to them as Bocks.
Unfortunately some versions can be lacking in their quality and durability. In this instructable i will be showing you 4 ways of making them more comfortable and durable.
None of these ideas are mine and have been documented on several other web sites, but i have decided to collate a few on here. If you do not agree with your idea being shown here please contact me and i will remove it.
As far as i can tell the first people to document these ideas are:
Tyre socks: Bill C of http://www.powerbockresources.com (A great site with all these tips and more).
Inner tube spring cover: Ray from New York City.
Webbing knee wrapping: Matt J., Centereach, NY USA.
This is my first 'ible so please give constructive criticism and point out any mistakes. Please post your own ideas too.
DISCLAIMER: I am not responsible for you damaging your powerisers or yourself whilst modifying them. This is only accuate for my pro-jump brand Bocks. Yours may be different.
Step 1: Tools and Supplies.
Size 10 spanner.
Size 13 spanner.
Adjustable spanner or another set of spanners.
Allen key set.
Awl or other pointy object.
A Phillips screwdriver.
You may want to wear gloves. The spring is a fibreglass composite and splinters are really annoying.
-An inner tube for a 26 inch wheel. One suitable for a mountain bike. Not a very thin road one. I got mine from ASDA for Â£1.80ish.
-A tyre. Mine is a 20' bmx tyre for road use. This is better than an off road one as it lasts longer. Try to collect old tyres when you get the chance. Free tyres are free booties.
-Tape. Mine is gaffer tape. Â£1 from ASDA, but if you can get a fabric tape like "hockey tape" use that instead/as well.
-2/4 Hose/jubilee clips. (see second picture) I got mine from Wickes, B&Qs selection was very poor. I got the largest supplied (30-40mm), but still needed to link two together so needed four in total. Cost: Â£1.19 for two.
-Webbing. I have two 11 foot strips of webbing. This allows three wraps and copious knots at the back. You may find different configurations more comfortable. Cost: quite cheap, but i used some from an old slack line so don't know the exact cost.
I have heard that the nylon lock nuts used on Bocks should only be used once as they lose their effectiveness when removed. If this is true, you may want a supply of each type of nut. I have chosen not to change them, but i give my bocks the once over before rding them and usually tighten each nut if needed.
Step 2: Parts and Dissasembly.
The first picture shows a pre-modded Bock. the relevant parts are labeled. The whole process is in one step with the pictures showing the order.
The disassembly process is quite straight forward, but some parts have to be removed in a specific order. Please only take one Bock apart at a time. This way you will not confuse parts and will have model to look at if you get confused later on during reassembly.
I tend to put the removed modules back together so i can keep track of all the parts.
Firstly you must remove the knee bar. To do this you have to take out the four screws on the back rest. Note that the front two screw have washers and that the back rest is not symmetrical (pic 2). Use the size 10 spanner and an allen key to undo each one (pic 3). After which it can be taken apart (pic 4). I put the assembly back together finger tightening the nuts so i don't lose any (pic 5).
Two size 13 bolts have to be undone before you can remove the spring and hoof (pic 6). Close ups (pic 7 & 8). Spring and hoof removed (pic 9). Again, try to keep each bolt with its fixings. You don't want to muddle which one has washers etc. Note The spring is not under tension so do not worry about it flying at your face when you take out the bolt.
Now you must remove the hoof assembly from the spring. Use the size 13 spanners to remove the black A shaped bit from the bushing (pic 10). This can be taken off of the spring using the size 10 spanners (pic 11). Note the two tabs which shield the spring from the bushing and the metal. Do not lose these.
The other black fixing can be removed from the top end at this point too (pic 12).
Your Bock is now ready for modding.
Step 3: Protecting the Spring.
As the spring is arguably the most important part of your bocks. Without it, you ain't got no bounce. It is also quite fragile. You will knock your springs against things and drop your bocks every now and then. Each time you do will chip and fragment your spring causing weakness. If you do it too much, the whole thing can snap.
Wrapping your spring will help protect it and can also be used to decorate it.
In this step i will be covering the spring in an inner tube. The rubber provides an excellent barrier.
I pull the inner tube over the spring, but some people prefer to cut the tube and wrap it around, taping it in place. Doing this means you don't have to remove the spring, but i feel it's good to take your bock apart every once in a while to check them. It also mean you can protect the tabs properly. Mine used to slip out and rattle around inside the hoof assembly. Now they are firmly in place.
Firstly, Cut the inner tube next to the valve Cut as close as possible to minimise waste.
Now, begin to pull the inner tube over the spring from top to bottom (Pic 2). It will become more difficult to pull the tube over the closer you get to the middle as the spring gets thicker. The most efficient method i found was to bunch the material up and then pull each bunch out (Pic 3). This means you are only trying to stretch a small portion of the whole tube at a time.
I stopped at the point shown in pic 4. The first time i did this mod, i covered the whole spring only to find out that it wouldn't fit under the bushing of the hoof assembly. By all means try it on yours (i hope it works for you), but it doesn't work on mine.
The plastic tabs are useful, but mine kept being forced out of their position. Usually with scary noises. A cracking noises is not good whilst bounding along. I now tape them in place (Pic 5). This has stopped it from happening on mine again.
Cut the inner tube off at the top end in line with the top of the spring (Pic 6). There Should be enough left over to do the other spring.
Step 4: Attaching the Tube and Taping the Spring.
It is now time to put the spring back together and tape it up. A few layers of tape will help protect the spring and allow you to decorate it. It also helps hold the inner tube in place.
The top attachment goes on first. Make sure you use the top attachment on the top of the spring and orientate it correctly. It is the attachment with the hook at the end. The top end if the spring is the one furthest away from the plastic tabs. The attachment should be on the outside edge of the spring.
You will notice that the tubing covers the holes in the spring. Use the Awl (or another pointy object) to make holes in the tube (Pic 1). Enlarge these with scissors to about the same size as the bolts.
It gets a little tricky here so i didn't take enough quality pictures, but the process is easy to understand.
You have to place the bolt through the attachment, the tubing, the spring, and the tubing again.
If the holes in the tube aren't perfect you will have trouble getting through the first layer. I use the scissors or needle nose pliers to push the tubing against the inside of the attachment allowing the bolt to pass though (Pic 2 & 3). Do the bottom first otherwise you find it much harder later.
When the bottom bolt is all the way through, use only the slightly tightened nut to hold it in place, not the washer and nut. the reason being that it is difficult to hold it all in place and fight the washer and nut on as not much of the bolt protrudes.
now put the top bolt through. This is easier if you stretch the rubber tube from the inside enlarging the outside hole. When this is all the way through, use both the washer and the nut. The other bolt should make it easier to fit both on. Then redo the bottom nut with both.
Tighten with the size 10 spanners. Only turn the outside edge of the bolt. If you twist both or the inside one, the inner tube will twist with it. Holding the inside and tightening the outside gives a much neater appearance and should make it stronger (Pic 4).
You can now start to tape up your spring. I used gaffer tape, but any tape will do. Fabric tape is strongest which is best for this. I go from the top to the bottom stopping at the end of the tube (Pic 5).
It is now ready to put the spring back on the rest of the bock.
Step 5: Reassembly
This is basically the reverse of the first step, but i'll guide you through it with pictures anyway.
Force the hoof assembly back over the spring and onto the plastic tabs (Pic 1). It will be quite a tight fit.
Attach the bottom spring assembly onto the inside of the spring using the two bolts and the nuts and washers. This is also quite tricky and it is again best practice to do the one farthest from the end first (Pic 2). Try not to damage the springs too much whilst fitting the bolts. That would go against the whole purpose of this 'ible. Try to put the bolts straight through, not on an angle.
Bolt the bottom assembly onto the hoof (Pic 3).
The middle bolt will need to be placed onto the main body of the Bock. Put the washers in the correct place (Pic 4). One on each side of the metal body.
Now bolt on the top assembly. Washers will only fit on the outside between the bolt head and the bushing(Pic 5).
Reassemble the knee bar and back rest on to the main body. Remember that the back rest is not symmetrical and that only the front bolts have washers(Pic 6). Before fully tightening, move the bar to the correct height for you in your regular bocking shoes. Should be just below the knee. Fully tighten.
Step 6: Adjusting the Bindings
The regular bindings are usually below par. I want to get some decent snowboard bindings, but can't afford it yet.
One thing that made them more comfortable was use the second hole in the strap (Pic 2). This made them smaller and they now sit on my shoe comfortably. They can also be tightened further.
It's a very simple process of unscrewing the strap and moving it over to the other hole. The back screw has a nut which can revolve. Hold this still with the pliers. Te front one has square thing hat is held in place by shaped plastic.
Step 7: Tyre Sock Booties.
The hoofs on your Bocks look like they'll last for ages. Unfortunately, they do not. A few weeks of use on asphalt can wear them down to the metal.
Buying replacements is expensive and sometimes there are none to be found online. Booties are a cheap and easy way to increase the life of your hooves and increase traction.
You can also get new rubber glued on at a tyre repair place, if you know the right people. I do not, so booties it is.
Step 1. Take your tyre and cut of enough to wrap around the hoof and go a little way up the arm (Pic 1).
The wire that runs along the inside of the tyre is not needed. Removing it (or bypassing it as i did) makes the tyre easier to manage and gives a tighter fit around the hoof.
Wrap tape a couple of times around the arm above the hoof (Pic 2) and then tape on one side of the hoof (Pic 3).
Now is the time to put the hose/jubilee clips around the hoof arm (Pic 4). I had to put two together to make them fit.
Now pull the rest of the booty over the hoof. Make it as tight as possible. Ideally it is a two man job. Start tightening the clips (Pic 5). If you use two, try to tighten both equally. Make them rather tight. You do not want that booty to slip (Pic 6). Do not tighten so much that the frame starts to bend. that would be really bad.
Now, sharp edges are bad for business, so wrap the clip in more tape (Pic 7). I ran out of tape so only one is done.
You may want to cover up any other sharp edges with hosing and tape if you have it.
Step 8: New Knee Wrapping.
The method for tying your knee to the knee bar on my Bocks is not the best thought out. You can't really get it tight enough and the thin strap can cut into your leg. Using leg armour does help (and should always be worn), but using webbing to lace your knee to the bar is a very comfortable and stable addition.
Tie your existing straps out of the way (Pic 1).
Take one of your straps and find the middle point (Pic 2), place that behind your leg and bellow the knee bar. Pull both straps in front of your leg and cross them over (Pic 3). Pull tight and bring them behind you leg (Pic 4), cross them over here to bring them back around to the front (Pic 5). Repeat and keep pulling tight. When you run out of webbing, tie it off (Pic 6). I use a series of reef knots (Pic 7), but any will work. A water knot is the best one to use on a loop of webbing, but I've never had a problem with my knots loosening. Keep an eye on it anyway. Just to be safe.
Step 9: Do It All Again.
Fix the other Bock. This time should be much faster.
Now, be more like tigger and get bouncing.
Remember to maintain these mods and the rest of your Bocks. You will need to change your boots when they wear out and wash your traps when they get sweaty. Also, change the tape every once i a while to give your bocks a new look.
Most of all, have fun.