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Mountain Lion - Section 2

Section 1   |  Section 2


To install the seat base, and allow it to be removable, a small stump of seat post tube was welded to a plate which is in turn welded across the fork legs (Photo 16). This will hold the back of the seat base into the original seat tube, and the front will then be bolted to the frame using the fork dropouts.
Photo 16 -Installing the seat base.


This chopper was going to have a seat with a backrest as well - when you are climbing those steep mountains, you wouldn't want to fall off the bike. The other pair of spare forks was cut up as shown in Photo 18. The legs were cut from the crown on whatever angle you need to recline your seat. Don't worry about the exact angle when cutting, you can always grind the forks later to get them the way you want.
Photo 17 - Parts for the seat back.


Once the four fork legs have been welded together to create your seat frame, insert the seat post stub into the seat tube as shown in Photo 18 then center the dropouts to the middle of the top tube on the frame. Make a hole where the bolt will be placed on the frame in order to connect the seat to the frame.
Photo 18 - Joining the fork legs to create a seat frame.


The bolts are either welded to the frame on each side, or a long bolt is used through both holes (Photo 19). Once installed, the seat frame will be hold solidly in place, yet be easy to remove.
Photo 19 - Bolting the front of the seat frame in place.


To try something a little different, the seat padding will be made from three small blocks. The blocks are made by gluing some 2 inch foam to a few squares of 3/4 inch plywood (Photo 20). Although the padding will be minimal, it still beats a typical bicycle seat which has an even smaller surface area, and almost no padding at all. "Wedgie" seats are evil!
Photo 20 - Making the seat pads.


The seat covering is made from the highest quality vinyl material money can buy - in this case $3 worth. Because the seat blocks are square, you will have to wrap the material around as if you were wrapping a boxed gift. Stretch the material as tight as possible and staple it on two sides, then fold over the other two corners and do the same (Photo 21). This method is not as nice as a fully sewn seat cover, but I don't have a sewing machine in my garage, do you?
Photo 21 - Staple material around the padding.


To complete the seat, bolt the foam pads to the forks by drilling holes and using woodscrews (Photo 22). Any number of pads can be positioned in whatever placement you like, just make sure the seat is at least a little bit comfortable for those long back road hauls.
Photo 22 -The completed and mounted seat.


The Mountain Lion has a large rear fender, cut from some scrap sheet metal of approximately 12 gauge. Photo 23 shows the three pieces that will be welded together in order to form the fender. The two side pieces were cut from the same pattern using a jigsaw, and the center strip is wide enough for the rear tire, and long enough to frap around the round part of the fender.
Photo 23 - making a fender from sheet metal.


To make the center strip conform to the curve on the fender, it is first tack welded to the end, then bent along the curve, placing tack welds at about every half inch (Photo 24). Just keep tack welding and bending until the entire length is completed.
Photo 24 - Bending the steel around the curve.


Once you are done tack welding and bending the center strip, it should form a perfect curve along the top of the fender (Photo 25). At this point it is easy to manipulate the sides to ensure the entire fender is aligned properly.

To ensure that your fender will be solid, and for that professional look, the entire length of the joint on both sides of the center strip should be welded. It's best to weld with the amperage a little low, even though the weld will be chunky, we are going to grind it all away anyhow. Better to do a bit of extra grinder work than to have to fill in a burn through on this part of the build.

Photo 25 - Tack welding the fender together.


If you have some patience, the finished fender will look factory pressed after you grind the welds (Photo 26). I always do the rough grinding with a heavy disc, taking the weld area almost flush with the metal, then I switch to a cut off disk for the fine work. Once the fine work is done (this includes re welding pits and holes), I use a sander disk to clean it right up.

Welding the small missed areas and pin holes usually takes two or three attempts to get right, so have patience and you will be able to make a perfect fender. Your grinder is your best friend when doing this kind of work.

Photo 26 - Completed fender, welded and ground smooth.


The rest of the components were installed on the bike, so it could be taken for a test ride before painting (Photo 27). It's always a good plan to do this, as any adjustments or additions will wreak havoc on your painted frame. Don't worry about cables, and shifter, just get the core components together to make sure everything fits, and nothing was left out of the design.
Photo 27 - Assembled bike ready for test ride.


Here is the completed and painted Mountain Lion chopper (Photo 28). The ends of the forks, head tube and rear triangle were sprayed black just like the original frame - the rest of the bike is red. Although this bike is a radical departure from the original bike, it still shares some of it's heritage - working suspension, 18 speeds, and off road capable frame. A chopper for hill lovers and mountaineers everywhere!
Photo 28 - Mountain Lion painted and ready.


Overall ridability of the chopper was good, the suspension still worked over rough terrain, and the seat pads picked up the rest of the road shock - better than the original seat. The front forks felt a little loose at first, but that was only because of the front suspension having a little play side to side. The original bike suffered from this as well. Notice the cool red tail lights installed on the rear fender sides (Photo 29).
Photo 29 - Adam poses with the Mountain Lion.


Adam rips down the back lane, heading for the deep wilderness bike trails (Photo 30). If you're going to hit the back trails and venture where no bike freak has ventured before, then at least do it in style - do it on a chopper!
Photo 30 - Head to the hills!


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