"Theoretically, according to the manufacture and my engineering training"

If I could choose between a team of metallurgists / engineers or a team of an experienced welders and buggy riders to build my buggy. I would choose the welders / buggy riders every time. They simply KNOW what works and what doesn't.

You might back off from disagreeing so much with others that have years and thousands of miles of experience. Your arguments don't even address the purpose or benefit of the jam nut. The only time I've had a wheel come loose is with a bolt without a jam nut. The purpose of the jam nut is to let you separate the torque of the bolt to the buggy, from the torque placed on the bearing races.

If you bend a 20mm bolt, it will likely happen when loading/unloading a buggy without the wheel mounted, during transport, or if you hit an immovable object with some force. However likely or unlikely it is, I'd rather be able to fix it with a wrench and a borrowed axle bolt than needing a shop to fix a bent bolt or damaged thread.

Quote: Originally posted by OffAxis

Can anyone confirm that PL or Flexi does not use a shim between the bolt head and the bearing on the rear axle?

Yes.
Outside to inside: bolt head, bearing, spacer, bearing, axel. (If you make it to the other end of the axel, reverse the order ) No other metal, just the wheel and tire (and a little anti-seize on the 20mm bolt).

Quote:

Yes. Outside to inside: bolt head, bearing, spacer, bearing, axel. (If you make it to the other end of the axel, reverse the order ) No other metal, just the wheel and tire (and a little anti-seize on the 20mm bolt).

Perfect, Thanks.

How bout you put your years of experience to use and build a buggy. After you figure out FROM USE your next question, you won't be asking why a mouse trap works.
WHY ARE THE PL AND FLEXI BUGGY's MADE THE WAY THEY ARE? Really? It's all about making money.
How do you make a bit of money with a kite company? Start with a LOT of money.

Quote:

How bout you put your years of experience to use and build a buggy.

Working on it.

Not trying to be an a$$, as we have Heard all of this stuff before. If anything else we've all thought it, and done it. Not to say that you're any better or dumber than we are as everyone is an expert in their own field, but it isn't until you've actually sat in a buggy that you built or someone else built, and traveled A crossed a surface of some type while powered by a kite that anything begins to make sense and you have some good questions.
Every buggy company in the world has built more than a dozen buggies before they came to some type of idea of how, what, why, that this one will be the production model.
If you want to improve on another design, then you have to understand why that design doesn't work that you're going to improve on. Or not improve on. Just saying sometimes we over Think things. As to the reference of the mouse trap, if it works why change it? But if you haven't tried it then?
We've all seen and read about carbon fiber buggies built by boat individuals, aircraft designers, and those who are exceptionally smart engineers. Sad to say they've all come and gone with nothing to show for themselves.

I did a comparison a few years back on tires and wheels on two different buggies. At the time the two buggies were top-of-the-line. Sad to say they both did exactly what they were designed to do, they only difference between the two were cost and wheels/tires. It wasn't the buggies that were better or worse, it was the tires and wheels that made the difference. I received is so much flack from one of the buggy manufacturers that they more or less Quit making that particular buggy.
Not sure as to how many buggies have been built by the average person, but I will step out on a limb and say that it wasn't there last buggy and that another one is in the works.

Go ahead and build your buggy. Then tell us all about it. We all want to hear your story of your success and failure. Until then you're going to get 1 million reasons why and just as many reasons why not to do this or do that. For me it was easier to improve on another design and rebuild one that I bought than just start from scratch and reinvent the mouse trap. Just my opinion.
So when are you going to start your buggy?

The Master's Degree in Counseling I just earned tells me that you are more interested in us confirming what you already think is right (in spite of it being excessive and/or not so right) because like many young people, you appear to be convinced that your education supersedes the experience of the great many people from who you are seeking advice.

My experience in rebuilding and modifying my own buggy tells me that you are really making this much much much too complicated in almost all aspects. Listen, I'm (like BigKid) not trying to be a jerk, but you would do much better to actually listen to the advice (which you posted here seeking!) than to be convinced of your right-ness... its called humble pie,... eat some.

I WILL agree with you on the point of axle bolt size being changeable with the ID of the inner race of the bearing. I use bearings with an OD that fits the standard PL hub (which I use) and a 3/4" ID and a 3/4" Grade 8 bolt. My wheels bolt through a 1/2" thick plate on either end of the axle and are held in place with a spacer between the wheel and the plate all held on with Nyloc's... VTT style, ...IMHO, it is the absolute most simple solution to the bolting the wheels on question:

More info here about bearing spacers.

http://www.extremekites.com.au/topic/12001-buggy-transport/?...

Jam nuts are just a solution to poor spacer manufacture. :barf:

Yep just build one and try it as there is no perfect solution to suit everyone's needs.

soliver, that looks way faster than a 28.5mph bug...even on the bench

I wonder if you have had the talk with Van that I advised ? He is somebody who came in with similar ideas to you but with tools, experience and a budget. If he had the educational background he didn't brag on it like it was important! ( but I suspect he does? ) I really think He can give you a balanced perspective and probably answer some of your questions. If you are setting out to fish in the ocean it's always good to talk to + LISTEN TO the seasoned fishermen.

Van did this the right way! He built some proto types and then took them to NABX. He encouraged everybody to pick them apart and humbly took their advice. Sort of your goal with WBB. He did a bang up job of building solutions for manufactured buggies drawbacks. For reasons I can't explain the adventure has soured for Him. Knowing the reasons he withdrew going in seems real valuable to me. But I am just a simple tradesman.

I suggest that you start on something if you want to have it set to be inspected this fall!

P.S. How does your engineering experience lead you to want to copy a PL comp? Possibly the most uncomfortable buggy made. Until Van and AWOC made after market stuff for them!

Information for future reference.

The purpose of the jam nut is to keep the bolt from coming loose from the Axle. You can NOT properly load the torque on the bearings AND load the proper torque on the axle with one bolt being torqued. The other problem is that when your bearing starts to get a little abused (dirty, heated up) it will begin to drag. No problem on the right side, but the left side will unscrew unless you use a reverse thread on it, which will be very difficult to find replacements for. The jam nut fixes all of these issues.


And NO, peter lynn does not use any spacers on the outside of their wheels/bearings, just one internal spacer between the two bearings. One bolt goes through everything into the axle.

Information for future reference.

Quote: Originally posted by abkayak

soliver, that looks way faster than a 28.5mph bug...even on the bench

... Thanks! it sure feels faster!!! and it sure does hold me in when my "Glorified beds sheets" get a little twitchy. I've redone so much of it that that I'm probably responsible for 80% of it myself... following Van's model of course!

Quote: Originally posted by OffAxis

Well this wasn't quite to feedback I was expecting. Regardless, I'm still interested in features or designs of buggies that you guys like. Also it was mentioned that weight distribution, rake and trail are important. Any input on those parameters?

Hey...

I am way late into this but...

As someone who has made their own buggy I will add what I learned.

PL and flexi geometry is good for one specific adjustment. As soon as you adjust the down tube length the geometry changes. That is why many others don't clamp the down tube as much of an angle at all.

Their seats are not deep enough for good bracing for the side pull.

Don't worry about wheels so much. There have been good ideas on attaching different wheels. Bottom line is if the spacer in the hub is good, nothing else really matters. I prefer my wheels to be tight! The proper sized spacer in the hub means you can torque up the bolts and you are not side loading the bearings. If you look at the shoulder on the nuts and bolts, you will see why a spacer is not needed. Nice bit of built in space like they were made just for us so bearings can run free!

Rake and trail will depend on the kind of buggy you are trying to build... Small sporty unit or an all out race machine will be different.

Look at what has been used previously and start there. Make changes and then... make more changes till you are happy.

Ron

Well said Ron

I'm slowly constructing the 3d model. Mocked up the front fork finally. I've also been digging around the internet for a supplier that can bend and flatten tube just to see what their price would come in at.

Before you lock yourself into a front fork, you could source your wheels first then make the fork to fit. ie: a set of wheels with midi tyres might pop up at a good price, or you find similar at a market and they may not fit a std barrow type fork. I keep the bigfoot fork on my Vmax whether I run midi's/bigfoots or 17" rims - it doesn't matter if it's larger than the midi's but it obviously doesn't work the other way round.

And keep in mind a decent mudguard - home made or bought from an atv/bike shop, it would be good to have the attachment points ready to go on the fork rather than try to add something afterwards.

I adjusted the front fork to fit these tire sizes.

Tire Sizes:
Standard Ribbed and Smoothie tires: 4" wide x 16" tall x 8" wheel.
Wide Tires: 6" wide x 16" tall x 8" wheel.
Big Foot Tires: 6" wide x 21" tall x 8" wheel.

The clear green wheel is the big foot tires. The gray wheel is a midi wheel.

you need to go buggy and stay off the computer a bit......jusayin

It would be best to get hold of some wheels with tyres to see the different sizes,
The midi is considerably larger than the barrow wheel. and the bigfoot is very much larger than the midi.

Here is a photo of my midi next to a bigfoot, i will be able to measure them properly if you wish.



From the looks of your buggy, it seems you are copying a peter lynn buggy. i own one, and i find the seats are not supportive enough, and way to shallow, There is no back support in them.
and your legs are typically up around your ears in them.

Have you had much experience riding in a buggy for long periods of time ?

In the PL (and flexi) low rails make it difficult to hold power down against those low rails. This kind of buggy is fine for cruising and fields. but for long rides it can become quite uncomfortable.

Higher (longer) side rails for a deeper seat, swan neck vs downtube for better rider position, and definitely some kind of backrest.

The european buggies are built much longer and the rider sits lower to the ground with side rails up under the armpits further,
this allows you to hold more power and a more secure ride.

sorry i can't explain it better, i am just not got at 'words'

Peter lynn, good for a giggle in the park, but lower, longer, wider for the reel cruiser feeling. a buggy you are sitting 'in' rather than 'on'

i figure if you are going to go to all the trouble of making your own, make it a good one :) and not just another PL/flexi clone

good luck with your build :)

Quote: Originally posted by igeighty

It would be best to get hold of some wheels with tyres to see the different sizes, The midi is considerably larger than the barrow wheel. and the bigfoot is very much larger than the midi. Here is a photo of my midi next to a bigfoot, i will be able to measure them properly if you wish. From the looks of your buggy, it seems you are copying a peter lynn buggy. i own one, and i find the seats are not supportive enough, and way to shallow, There is no back support in them. and your legs are typically up around your ears in them. Have you had much experience riding in a buggy for long periods of time ? In the PL (and flexi) low rails make it difficult to hold power down against those low rails. This kind of buggy is fine for cruising and fields. but for long rides it can become quite uncomfortable. Higher (longer) side rails for a deeper seat, swan neck vs downtube for better rider position, and definitely some kind of backrest. The european buggies are built much longer and the rider sits lower to the ground with side rails up under the armpits further, this allows you to hold more power and a more secure ride. sorry i can't explain it better, i am just not got at 'words' Peter lynn, good for a giggle in the park, but lower, longer, wider for the reel cruiser feeling. a buggy you are sitting 'in' rather than 'on' i figure if you are going to go to all the trouble of making your own, make it a good one and not just another PL/flexi clone good luck with your build

i80 nailed it. Many of us own PL buggies and pretty much wish we didn't. I've gotten part way towards what i80 is very correctly referring to with a VTT rail and seat upgrade kit for my otherwise stock PL Bigfoot+. Well not quite stock as I did upgrade to Sysmic rims and new tires that I bought from the venerable Utahtami (speed demon extraordinaire), but the wheels were a pure pimp-my-ride upgrade and had nothing to do with form or function. I've thought long and hard about upgrading to a swan neck front end and may pull that trigger someday for the functional reasons noted by i80.

Memory serves that early on in this thread it was suggested that you contact Van for insight as he went through an evolution of sorts along exactly these lines. Having gotten to know him a bit over the past year I too can join the long and distinguished list of folks that are very glad they know Van. Dude knows his stuff and you would be well served to reach out to him in the event you haven't already done so. At the very least, consider working towards designs more akin to his buggies than standard PL or Flexi styles.

Please trust what you are hearing; the sitting "in" versus "on" stuff is real. The side pull you experience for long periods of time such as during beach runs or long shots on dry lake beds really put a strain on your body after a while. Why go to all the trouble of a build and then a long ride only to be unnecessarily uncomfortable?

I've enjoyed this thread from afar. I hope your build goes well. This does look like a fun project! Good luck.

igeighty: those tires are rediciclous. What size is that?

This process is definitely an evolutionary process. Thanks everyone for providing feedback about various buggy feature pros and cons, keep the ideas coming. I do need to mock up the more finalized design to verify seat shape, comfort and ergonomics. The next few weeks are crazy for me so i suspect progress to be slow. So stay tuned. I want to make sure the design is "finished" before I fabricate version 1.



Digging around the interwebs I was able to find some further information about buggy backrest mods:
http://www.powerkiteforum.com/viewthread.php?tid=8822
http://www.powerkiteforum.com/viewthread.php?tid=8698

Has any every tried making a hammock style seat? Thoughts?

you get dirty, wet, whatever covered in enough when riding as it is...i wouldnt go w/ any open weave
although the 1st bugs kinda did...but in essence all my seats are slung hammock like, just solid fabric
would like one of those for my front porch

Hi Offaxis

The large wheel is a Kenda beach racer 21x12-8 on a Sysmic 8x4 inch alloy rim.
The wheel next to it is a Kenda Midi Tire 16x6.5-8 on a Peter Lynn 8x2.5 inch rim.

I started life in 1995 on a Peter Lynn Mk1. It was a tiny thing with a webbing seat, i would always get mushed up bluebottles spraying of the front wheel on my balls with the webbing seat. It was a great little buggy. but at the time there were not any other designs out there.

After a break i returned to kiting and bought a Peter Lynn Comp XR+ (pictured below) just because it was what i knew. but being nearly 20 years older i found it had no back support and i always felt like a hunchback riding it. although an improvement over the mk1, it still felt like i was sitting 'on' it rather than in it with my knees around my ears.

I then bought a GT race buggy after sitting in some of the other guys bigger buggies that where so much more comfortable. There are a few peter lynn's down under. However most guys have bigger buggies.

Peter Lynn comp xr+ with larger front fork. and midi wheels


Front to back,, my GT-Rapide++ (beach racers) Roblukins GT-Radical (midi wheels), john holgate's libra vmax (beach racers)


GT-Race rapid ++ with beach racers


Notice the low sitting position with straighter legs ?


Johns Vmax,it has a very low body centre, much more comfortable for long rides. He uses beach racers and midi's depending on the surface. Robs radical is essentially a smaller GT-Rapide, same thing, low body centre, very stable, very comfy. He is usually first on the beach and last off. (most of the time the quickest)

There are many many different designs out there. But i my opinion (others may not agree) i feel you dont need to 'race' in a race buggy, but they make VERY good cruisers with a deep seat, good back support and longer distance to the pegs via the swan neck. the tradeoff is that they are inherently larger. I used to get very exhausted in the peter lynn, but in the GT i can ride it all day and still much it up the sand dunes at the end of the day.

Sysmic made a great buggy that was not as large as a racer, the S1. it maintained the low centre of gravity and length, while still keeping it relatively small. A fellow we buggy with, Michael has one, as it is a real rocket.



I love my peter lynn, don't get me wrong. I think they are a great buggy for ratting around a park or oval and before getting my bum into Clives libra majestic, i would never have known the difference. however once i did park my ass in race buggy. i was amazed at the difference in the comfort, not to mention the control. and how much extra speed i can hold down. I'm not sure i could go back 60 kph in a peter lynn is a bit of a brown pants moment, but 60 in a larger race buggy just feels good.

As for your hammock seat design, peter lynn and flexi used to do this method, as did land lizard and other 'vintage' bugs. Its what we had back in the day. Everyone had seats made of webbing, but they are a bit sketchy when compared to a fully protected nut sack in a nice firm cordura seat

Deep seating position with firm back support is fantastic. unfortunately my peter lynn even with its newer style seat just doesn't give me that support. Nearly all the guys who have one extend the side rails and make back rests. and for the cost of a peter lynn or flexi or zebra, a few extra dollars gets you a lower sleeker and more comfy ride.

Get your ass parked into as many different buggies as you can, and you will see the pro's and cons of the many different designs.

If i was welding my own, it would definitely be something more 'race'

good luck with it man. i am envious of anyone who has the smarts to build there own

regards.
Doug

igeighty is spot on with his input!

Webbed seats didn't last for many good reasons. Sort of like wheel barrow wheels.

As I mentioned at the top, you are trying to copy about the most uncomfortable buggy I have ever used. Getting some seat time will show you what we are all saying.

If you don't get started building soon I don't see you making your goal of having it for WBB this fall? Maybe the best thing you can do is hold off until you have been to WBB. Folks there will be happy to let you try some more beefy models. This is of course assuming you have your kite skills down? If not, You are putting the cart before the horse!

What does Van think about your ideas?

I have the xr and with a simple backrest its very comfortable. I'm only 5'9". I would not recommend it to anyone taller than that. I agree, in it's stock form it's barely usable, but with a couple simple mods it's very comfortable as long as your short.