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If ever I was to sit down and design a kite buggy, that was reasonably simple in design, therefore economical to make, which had good balance coupled with a rigid chassis and scope for upgrading, I feel like I would end up with something not too dissimilar to Rob Hills' Flexifoil, by that I mean it is difficult to improve on his basic design. In practice any design of this nature is going to be about not how good it is, but how long it stays good! Before I bought mine I had a go on just the Flexi and a couple of Peter Lynn's. With my budget being what it was at the time I figured pretty soon that the extra money spent on the Flexi would pay dividends, even before sitting in one. From a construction point of view in was clear that, in my view, the Flexi was far superior to the PL's. Generous tube sizes coupled with joints that allow all around welding were clear to see. The use of plastic inserts where the rear axle meets the side rails indicated that any movement between them would be reasonably free of metal to metal contact which helps the longevity of the joint. And allows wider tolerances which won't manifest them selves as creaks and moans. Whilst ball raced bearings may seem to be a good idea in the headstock bearing their introduction means fussier, therefore more expensive, manufacturing tolerances and something else prone to expensive replacement. The Flexifoil uses simple plastic bushes, possibly PTFE, and this ever so simple approach has survived hundreds of miles of use without any problems. The forks for the front wheel are, again, of simple design, and permit the fitting of wider wheels without modification, but the standard wheels still look as if they belong there, with no visually poor gaps between the wheel and the fork legs. The seat is a very well stitched tough fabric with a backrest at a height which suits me well for trick buggying, which is fitted with a removable stiffener retained by a Velcro flap. There is virtually no adjustment in the seat though, but I have had virtually no reason to adjust the seat apart from when a wide axle was fitted! The footrests have turned up ends, which prevent your feet from sliding off, and provide some ground clearance when you're up on two wheels. Provision for fitting foot straps is there in the way of flattened, drilled and turned up tips. The 'finish' of the buggy is what a surveyor I know would call 'speculative', that is it's good enough to show that it could be better. The buggy is made from polished stock Stainless Steel tubing, and the only re-polishing that has been carried out is to remove the surface discolouring after welding. In most places this means that the welded areas are shinier than the rest. I'll come to that later. Unfortunately the packaging was not all it could be, and on opening the box it was clear that some cosmetic damage had occurred as the various bits rattled around in the box. Probably the least attractive areas of the stainless bits are where the tubing had been bent. Stresses from bending show themselves as a matting of the surface on the outside of the bend, this is particularly bad on the forks, as this is one area where the bends are not masked by other fittings. The ends of the foot pegs have been linished to remove burrs from the drilling for the foot straps and appeared comparatively dull to most of the rest of the buggy. The welds are of reasonable standard, but because of the design of the joints they are 'all around' welds, where on some buggies the design limits access to allow full welding which is not something I'm comfortable with. Where the side rails meet the down tube they are terminated in plates with folded top and bottom edges which comply reasonably well around the square section to which they fit. Shear marks from this bending process are quite deep, which is disappointing because they are in direct line of sight when sitting in the buggy. The seat is very well stitched with no loose threads and a pair of embroidered Flexifoil logos fixed front and rear of the backrest display the, often hallowed, manufacturers name. Wheels are standard fayre. Robust, tough, basic mouldings fitted with 'barrow' tyres and inner tubes provide simple and proven contact with the ground. Assembly of these is less than straightforward. Fortunately the supplied instructions are very well laid out with quality photographs showing how it all goes together. The fitment of the seat is a bit of a challenge as it is important that the straps are all in the right place before the fitting of the rear axle, otherwise disassembly is needed to correct it all. The rearmost seat straps are fitted via a double wrap around the side rails, then routing to the back axle, and it is here that the instructions need to be closely looked at. Many times I have seen misassembled straps on Flexis. I found that the loose ends of the straps once tensioned on the buckles can be wrapped and tucked it in a neat manner to stop things flapping about. When fitting the side rails to the rear axle attention is needed to ensure the bolt holes in the plastic sleeves stay in alignment with the holes in the axle tube. A little judicious 'podging' with a large screwdriver can finalise the alignment before inserting the bolts supplied. Flexi provide a small tube of copper grease to apply to the threads of the nuts and bolts, definitely a good idea. My experiences in Marine Engineering have shown me that stainless fasteners can 'pick up' and literally weld together under the friction of even hand tightening. Often the only way to remove such welded bolts is to cut them off! The copper grease makes this problem far less likely to occur. Two small adjustable spanners of low but operational quality are provided for tightening these bolts, though I did not use them, as adjustables are a serious compromise on any bolt unless they are of the best quality. Nice thought though. Some plastics swell when they get wet, and the reasonably close fit of the fork stem into the headstock directed me towards using a heavy silicone grease for the bushes, the type of grease intended for the assembly of plastic push fit plumbing. The footrests are quite a loose fit in the fork sockets, but as I had no plans to remove them in a hurry I tightened them enough to squash the sockets down slightly to stop them rocking. Having fitted the wheels the final job was to put the splash guard on. The rear centre of this is retained by a tab which just tucks into the open end of the down tube, but as I had the buggy set to it's maximum length I found that the rear side rail bolt could be passed through this tab for far better retention. The splash guard is tensioned on its rear corners by an elasticated line which, via plastic hooks, are connected to dedicated loops sewn into the seat. It was here that a problem occurred. Both the hooks on this line came off as soon as the elastic was tensioned. No amount of refitting would allow them to stay there. It was clear that the cam lock fitted hooks were intended for a bigger diameter line than that used. An email to Flexifoil resulted in a prompt delivery of a fresh pair of hooks, which unfortunately made no difference to the problem. I resorted to applying epoxy resin to the ends of the elastic to provide a solid 'ball' on to which the cam locks could grab. They have been there ever since. I then went through all of this again! Having learnt about the wide axle accessory another standard buggy was bought with the wide wheel option with a view to making up a wide axle myself. Reality dictated that this was going to be difficult to arrange, so I bought in a Flexifoil wide axle with which I must say I was quite disappointed with when I first saw it. It would appear to have been transported without any protection at all. The surface was damaged with quite deep scratches, and whilst it was clearly a new one, I thought £100 for this was a bit of a let down. But it got worse! Assembling this WA version was fraught with frustration. The side rail element of the axle has sockets for the seat rails that are much deeper than the standard one. It was here that manufacturing tolerances showed themselves to be a little on the slack side in that some effort was needed to get the seat rails into the sockets whilst keeping the longer than standard plastic sleeves in alignment, needing loosening of the side rail to down tube. A twisting action to help then in is difficult with the seat having to be in place. This was a little frustrating, but worse of all was that having fitted it all together it was apparent straight away that the seat was higher then the standard, arguably the opposite to what one would desire in a conversion intend to improve lateral traction and therefore speed. The reason for this appear to be two fold. The bend in the axle side rail is not quite of a steep enough angle, and the side rails do not fit into these deep enough to allow them to adopt the same position as the standard buggy. The result is a 40mm increase in seat height which is very noticeable when sitting in it. I'll come back to this. In use the standard buggy move along quietly with no creaks and squeaks which is reassuring. The only thing to be heard is the tyres on the ground and the wind. Lovely! The buggy is geometrically balanced with good steering head angle correct for the operation of turning. Some under steer is apparent if you're weight is too far back when applying big steering input, but a shift of body weight forward improves this no end. This body action also improves the lack of lateral grip if your flying powered up, though it's the WA version which gets the best out of this buggy in higher winds if speed is your aim. The longer and wider axle places the kite pull more into the centre of the buggy resulting in a better distribution of load to the wheels, and increased lever advantage to prevent break out of grip. Whilst pulling two wheeled stuff in the WA is quite easy to achieve in spite of the extra width, in the standard one it's a joy. The standard buggy rises up without effort and can be kept there with ease by applying corrective input via the steering. The turned up ends on the foot pegs mean high angles are available and the airborne wheel can be gently lowered to the ground without thumping it down and risking the bending of either the axle or the wheel bolts. Heading backwards makes the steering super sensitive, with careful and tight control needed over the steering to prevent spin outs. Conversely this means spins are there to be had with the appropriate left right application of steering input to the front end as the rotation is in progress. I would suggest that the WA is worth about 8 - 10 MPH straight out of the box as more of the kites pull is transmitted into forward motion, rather than being lost in a constant rear end slide with counter steering having to be applied to keep the buggy tracking straight. Me being me leaving the buggy as it is was never on the cards. The down tube has a 'speculative' brushed finish which I covered up with some carbon fibre effect vinyl. The need for fitment of some form of padding to the side rails was made obvious after a few elbow dings. With the method used to fit the seat tube type padding was not an option without much cutting out of clearances to fit around the seat webbing loops through which the side rails are fitted. I was able to secure a number of roof bar pads, which have a 'saddle' type method of fitting which have proved to be a good way of overcoming this problem. On the WA version I have fitted the more usual tube type roof bar pads in addition to completely cover all areas prone to me smacking hands arms and control handles onto them. Home made foot straps soon followed on both. A simple cycle speedo has been fitted, and a back rest was added to the WA for chilled out runs, a belly pan made up to provide some protection from impact from below, and plans are afoot to deal with the seat height problem. The methods available to me here are: To lower the seat within the frame by remaking the loops, or adding extension pieces. To drop the rear axle, by making up a couple of bolt on pieces to fit to the ends of the axle. To fit Peter Lyn XR seat, and to adjust the depth to which the seat side rails are fitted into the axle sockets. In reality I think it's going to be a combination of two or all of these options. In addition I figure a swan neck in the down tube would all help towards getting the seating height, therefore the centre of both gravity and pull lower down to aid that aim of transmitting more power from the kite into motion. Or I may just buy a Libre Hardcore and have done with it. I've started a process of mirror polishing the buggies, because I like shiny things, including linishing off the bruise marks from the bending processes and removing the stamp marks on the bolt heads. It's my way :. A seat belt has been fitted to the standard, and a stiffened rear axle is in process for impending attempts at getting airborne. After a pretty intensive season on both buggies I think they are in as good a condition as they were to start with. Apart from a need to replace the wheel bearings on the rear of the WA there are no signs of fatigue in any areas and the indications are they will continue to give good service for some years to come. No perceptible wear has occurred in the steering head bushes and the tyres are still in sound condition. Some compression of the ends of the tubes which space out the bearings within the wheel has occurred which may require a thicker walled tubing to be used to prevent reoccurrence. It is possible that bearing failure can be induce prematurely if this tube loses length as it is compressed by repeated tightening of the wheel bolts. This places a side loading on the bearings which is not desirable. In conclusion then the Flexifoil buggy is a solid and simple machine, which has proved itself over a serious battering during the first year of use. As I said, it is difficult to think of any ways of improving the fundamental design, at least not without adding considerably to the cost. So hats of to Rob Hills and Flexi for a sound product, which has become a firm favourite. By : Jerry

I have been jumping "badly" in my buggy for about a year and its starting to show as you can see in the pic the front wheel is skewed and the rear axle is bent slightly. I have decided to modify a second buggy in these areas in an attempt to stop the buggy getting damaged from bad/heavy landings. After doing some research into the different ways other people modified there buggies it became apparent that most people do there own thing. If you look at other buggies on the beach or in the forums this becomes obvious quite quickly. So it really is a bit of an open book as far as what is the right way to do this. This is the way I have chosen. Time will tell me if it's a good way or not. Before I continue a word of caution. One school of thought says you should never modify the buggy at all. The logic behind this is that if your buggy is being damaged due to impact it is absorbing forces that could potentially damage "you". Also by strengthening the buggy in various areas you might just cause the next weakest part to fail. Taking this into consideration I decided to continue any way as I am heavier than the average buggy jumper. I decided that I wanted a brace over the rear axle and to put strengtheners across the side rails. Rear Axle. I wanted to have a single brace over the total width of the axle. I made it using 38mm OD stainless 316 tubing. I wanted the contact points to be almost to the end of the original axle so that it gave me the strongest fixing and was therefore welded onto both threaded bosses. Some axles are supported further in from the ends on the tube wall. This can still allow the original axle to bend at the weld points. The tubes were purchased at a local steel merchant. I also bought a 90degree bend. Which I then cut onto two 45 degree sections to provide me with the equal bends either end. Before the tubes can be welded I needed to prep the tube ends so that there was a minimal gap for the welder to fill. This is quite straight forward around the bends where straight butts are all that are required. Not quite so easy around the area where the brace sits on the original axle. You have to allow for the removal of the material when you cut it to length. If you mess this up then the brace could end up to short. I used a hack saw, various round and half round files and a protractor to prep the joints. This is quite time consuming but the results are worth the work. I wanted to have the axle brace welded in a position where it would give the optimum support, but not be right behind my back when I landed. I decided to weld the brace with a 60 degree angle between the brace and the side rail connections. This would leave the brace leaning slightly back in the finished buggy. Side rail strengtheners. I took the basic idea from a document that Stupid Dave (Flexi Pro Rider) had of his trick buggy mods. Highly recommended if you can get hold of this as he also shows other potential mods. The strengthener consists of a bar and two posts that effectively tie the two side rails together. This should provide extra rigidity that will help to stop the front end twisting. The materials I used were from an old damaged Radsails buggy. I basically cut up the rear axle to provide me with parts that I needed. Again the forming of the tube ends is quite tricky here as you have to ensure that all the butts are good for welding. I found that using some electricians tape here was very helpful to keep things together. Once the joints were prepped I was ready for the welding. As I did not have any access to suitable welding gear (MIG or TIG) I needed to find someone who could help me out. A friend of a friend came to my rescue and I managed to get the job done for a few quid. I was lucky, but there are many small workshops that could have done the job for me. Price is usually quite high for welding though. Again here is where the prepping of the welds can save a lot of money as the welder can work quickly. Once back from the welders, the frame was stripped and welds polished off to give a nice clean finish. The weld form was left visible and not polished out as I want it for strength. A basic drill, polishing discs and polishing soap were used to achieve the required finish. Warning; do not press to hard when using the drill as it can burn the motor out. (I found out the hard way) I had a little help in this area from one of the buggy polishing maestros. Guess who? One of the problems with welding the side rails is the welding causes the frame to buckle as the weld is forming. This means that some force is required to get the side rails and rear axle back together. It also meant that the down tube is now very tight into the front clamp. The buggy is now effectively one piece as far as transporting to and from the beach it is concerned. Seat mods. The Flexifoil seat is designed to fit over the side rails before the buggy is assembled normally. This gives you a problem when the side rails have been welded. The seat will not fit because the front two loops are to narrow. In order to get the two parts to fit modification of the front loops is needed. I machine and then hand overstitched two lengths of webbing onto the loops this allowed me to fit a plastic buckle to each side of the seat. Now the seat can be fitted to the side rails. Do this before fitting the down tube. With the frame of the buggy assembled the seat buckles can be tightened. I wasn't sure about the plastic buckles at first but they do seem to holding up during use. If they prove to be a weak point they can be upgraded to steel or the strap could be stitched together. I have also made a single lap strap for my bug as I prefer this over the three belt system. With the addition of the barrows and a belly pan the buggy is ready to fly. Note: jumping buggies and using lap belts will hurt. Maybe sooner, maybe later. But it will happen. You have been warned.