This page is... UNDER CONSTRUCTION
WARNING: I am not an expert on cars, automotive engineering, VW Beetles, beach buggies or anything else discussed in these pages. What I have written is my current understanding of the issues involved in building MY buggy. These opinions are based only on my own research in books and on the web. They, therefore,have no basis in fact, may well be wrong and potentially downright dangerous if taken to be gospel truth. If you intend to use any of this information for any purpose other than pure entertainment, then please get its validity confirmed by someone who knows what they're talking about! You have been warned...
This page contains the following sections:
My design aim for the front suspension is to increase the ground clearance, wheel travel, damping control, width (to match 3x3 rear trailing arms) and strength beyond what the stock VW Type 1 is capable of. I'm aiming for around 18 inches of ground clearance, 12 inches of suspension travel and a track width that is 6 inches wider than stock.
Having already decided to go with a ball-joint chassis (see the 'Design Detail - Body' section of this site), my front suspension choices are limited, as virtually all after-market suspension upgrades are aimed at king-pin front suspension.
The available options for improving my front suspension performance are as follows:
This involves cutting the centre section, that locates the torsion leaves, rotating it and then re-welding it back in place. The effect of this is to increase the load on the torsion leaves, which in turn raises the front suspension.
This is very similar to the cut & turn method described above but instead of re-welding the centre section in a fixed location, an adjuster is welded in to enable further adjustment without the need for more cutting. Adjusters commonly come in two forms; namely the Sway-Away and the Avis type adjusters. Of the two types, the Sway-Away adjuster is better, as it is less likely to move whilst in use.
This method is again similar to the cut & turn method described above but requires two beams and two sets of torsion leaves as a starting point. The result is that you end up with a single wider beam with four adjusters and four half sets of torsion leaves.
As the VW Type 181 was designed as an off road vehicle but was based on the Type 1, it has significantly improved front suspension both in terms of its strength and its ground clearance over the Type 1. This type of beam can be used with any of the above techniques to increase the ride height, adjustability or width, as required.
Whilst the above techniques can be used to improve the ground clearance, adjustability and width of the ball-joint front beam and a good set of shock absorbers will improve the damping control, none of them will improve the amount of wheel travel available, as this is fundamentally limited by the ball joints themselves. Even though long-travel ball joints are available and are used widely on street driven cars to lower the suspension, they are not strong enough for off-road use, as they are weakened by the amount of material that has to be removed from them to give the increased movement.
The only way to overcome this limitiation is to ditch the ball-joints completely and one way of achieving this would be to cut off the ball-joint frame head and to mount an after-market king-pin front beam by fabricating tubular mounts that tie it into the roll cage.
Whilst this is a fairly common technique, in order to achieve the increased suspension travel, the after-market king-pin beams use much longer shock absorbers which, in turn require much taller shock towers to support their upper ends. Even though I have an 80mm body lift kit on my buggy, it would be necessary to cut holes in the front wings to enable the taller shock towers to fit. I don't want to do this, as the Doon has an opening bonnet and has the headlights mounted on the front wings and the cut-outs would interfere with either, or both of these.
As well as not wanting to cut the body, there is another reason why I chose not to use this method. With after-market king-pin beams, the increase in travel is achieved by using longer and wider trailing arms, which in turn moves the wheels backward. This is usually overcome by moving the beam forwards by at least the extra length of the trailing arms. However, on the Doon, the front beam is already only just behind the front of the body, therefore, moving it forwards would put it in front of the body, which would look very strange!
Until recently, use of an a-arm front suspension set-up would have involved a great deal of custom fabrication work and since I am neither a suspension designer or welder/fabricator, it would have been prohibitively expensive to commission an a-arm set-up for my buggy. However, a bolt-on a-arm front suspension kit is now available for either a king-pin or ball-joint chassis from A-Arm.Com. This kit is designed to work with a 3 inch body lift, it widens the front track by 6 inches and moves the wheels forward 2 inches from their stock location. It gives 12 inches of suspension travel and significantly increased ground clearance.
I will, therefore, use an a-arm front suspension kit on my buggy.
Click here to see a video of front and rear suspension on a Baja Bug working well.
Click here to see a slide show of the a-arm kit as it was when it arrived.
Frame Head Modifications.
Click here to see a slide show of the frame head modifications required to fit the steering rack.
The spherical rod end bearing was developed by the Germans in World War II. When one of the first German planes to be shot down by the British in early 1940 was examined, they found this joint in use in the aircraft's control systems. The H.G. Heim Company was given an exclusive patent to manufacture these joints in North America, while in the UK the patent passed to Rose Bearings Ltd. The ubiquity of these manufacturers in their respective markets led to the terms heim joint and rose joint becoming synonymous with their product. After the patents ran out, the common names stuck although "rose joint" remains a registered trademark of Rose Bearings Ltd. Originally used in aircraft, the spherical rod end bearing may now be found in cars, trucks, race cars, boats, industrial machines, and many more applications.
High Misalignment Bushings.
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