Bal gewig

Ek het nou weer so vlugtig deur dit gelees en afgesien van die bal gewig het dit net weer vir my duidelik geword wat my Ingenieur (Eric Essmann, Duitser en 100m naloop kampioen) destyds vir my gesê toe ons gepraat het van woonwa sleep. 

Kyk na vliegtuie, die stadige groot Jumbo's het 'n groot neus en 'n klein agterkant, waar die hoë spoed stralers weer andersom gebou word.

Dit wil sê hoe stadiger hoe hoër is die "drag" daarom die klein gat, wat hy bedoel is ons moet eerder kyk mo die "drag" te verminder om sleep gemakliker en stabiel te maak.

Hier is informasie wat ek in 2014 op daai ander forum geplaas het.

Re: AIRTAB

I have recently attached the Airtab vortex generator solution on my Gypsy Gold Caravan in order toreduce the amount of ‘drag’ experienced due to wind turbulence.Having had the caravan for 4 years I always found that it was difficult to maintain a constant speedon relatively flat roads where there are slight undulations. It is very frustrating to have the powerbleed away resulting in having to change gears where there is only a small increase in the roadgradient.I have found that there is a marked improvement having put on Airtabs and the improvedaerodynamics has noticeably improved my straight line speed and in so doing reduced my fuelconsumption.I would recommend Airtabs to all my caravanning colleagues.

Regards,
Gary Fraser

Sou jy belangstel hier is die Airtab web en die skakel na my draad op die ander forum.

Môre Chris, lyk ky ek het jou verkeerd verstaan wat die koppeling betref, ek sit met dieselfde probleem, my kar is baie laag en die neus van die wa is naby die grond.

Ek het al "air springs" (High Lifters) oorweeg, maar die kar is nog onder waarborg, dus mag ek niks verander nie.

Ek hoop jy kom reg met goeie advies hier want ek sal ook moet plan maak vroeg in 2021 as die waarborg verval het.

My plan is om na 4 x 4 Mecca te gaan vir die taak.

Wat my egter verbaas, is dat jou Ford so laag is agter?

Ek het van daai air bellows in die coil op my Ford laat in sit by LA Sport in Voortrekker want hy het het so 25mm traveling gehad dan rus hy op rubbers, nou pomp ek daai rooi ballone so 1 Bar en dit werk.

Daai gewig verspreider is seker maar die selfde as die Tando en die ou Jurgens arms wat gebruik was ?

Dankie Chris, die 395 mm is omtrend standaard👍

Wildehont, With my Landy, I got A pair of “spring-assist” air-bags...

Completely different kettle of fish to air suspension, which, thankfully, has been exchanged for coil springs.

They fit inside the coils of the spring, and the thin pipes (kind of festo air pipe) are connected through a T connector to a tyre-valve fitting that get’s mounted through the rear bumper.

The purpose of them is to assist the springs with loading, and prevent rear-end sag. You can inflate them or relase then as per the loading on the back.

This may be a 4th option, if there is something available for your Everest.

I’d offer them to you (freebee) but you are in Wouster, and I’m JHB...

The THIRD option would be to have 2 new springs coiled up for your Everest, but that would obviously make the ride harder.

To make a spring stiffer, you have 2 options: -

(One), to make the diameter of the wire thicker and (Two) to remove wire from the spiral, IE reduce the number of coils, but keep the free length the same. That’s also not that much, you would be surprised at how much three-quarters of a coil on a spring makes... (it’s more about the  percentage of wire in the spring, not so much the empirical length)

If you go the route of thicker wire, (and it’s only a small amount, again, not as much as one may think), ensure that the MEAN DIAMETER remains the same and that OD and the ID will fit on the mountings  There should be a fair amount of room on both the ID and the OD, but just check.

Unfortunately, the spring design program I had was RDP’d when the company got knocked a couple of years ago over Christmas, so I can’t give you guidance, so if you choose that route just a few things to bear in mind so that your upgrade is successful, a good spring making company would be able to see you right, it's pretty basic basic calculations

NOTE: - If you choose this route ENSURE that the spring maker understands that the free length of the new spring MUST be the same as the existing spring AFTER SCRAGGING.

SCRAGGING  when a spring is coiled from new it will collapse a percentage SCRAGGING is they press the spring to solid height, a minimum of 3 times THEN the free length is as per the original spring.

You don’t want to make a stiffer spring, then it “sets” and the rear of your vehicle lands up being lower anyway so you get back to square one with the vehicle lower at the rear.

OK so that’s the new spring’s route.

There used to be a device that you inserted in between the coils of the spring, which connected the coil above with the coil below, thus “removing” a coil – portion of a coil out of the spring thus making the spring stiffer... Don’t know if you can still get them or how effective they where, so I won’t comment on them

Any help?

Warren, that is what I have fitted to my Territory, but Chris Everest does not have coil springs.

My Everest het bladvere agter.

but Chris Everest does not have coil springs.

My Everest het bladvere agter.

Ah-Ha.... Problem's easily solved... There is a device for this, I'll try and find a pic, but shortly, its a strong tension spring, connected to a rod at each end that sits above but in line with the blades, and connects the front and the back pivots of the leaf spring. You are able to adjust the tension of the spring..... Let me browse around....

Not exactly the one I had in mind, the one I know works between the 2 ends of the spring but same thing....... There was a discussion on 4x4 south africa forum on these

Any help?

Hi W

We got EISH-kom power back.

It's always better to tow weight than to carry weight. From what I gather, your vehicle is heavily loaded, (the suspension's on the soft side) and the additional force of the noseweight of the van + the load in the back of the car is causing your car to sag at the back, (bum-sag) and you are 100 % correct, that takes weight off the front which could well compromise your steering / roadholding at the front. 

100 % in agreement

But here is where I get controversial, and 1000 forum members will screech blue bloody murder at me... If you can't reduce the weight in the vehicle, consider a Venter trailer towed behind the van... IE Tandem tow.

Going back to the principal that it is much better to tow weight, than to carry weight, That is the principal of a freight trein. Once the train is in motion the locomotive is only expending power to keep all the carrages moving, and all the momentum of all that weight actually "pushes" you along.

Broad brush strokes, and not to put a too finer point on matters, the only additional is the TARE mass of the trailer + the rolling resistance of the wheels on the trailer.

(Now the whole blooming forum's gonna screech)

What I would look into is: - the light bulky stuff from the van & the car into the trailer, re distribute the weight  in the van so that you have a nose weight in the 100Kg zone and a lot less in the car (more space in the van taken up with stuff from the car, if that makes sense)

Remember, load the trailer FIRST so that you have a nose weight of +- 100Kg, THEN attach that to the van (it will affect the nose weight of the van) then load the van to the correct nose weight,

If you do it right the trailer & the van will be slightly nose down which is brilliant, the car won't have bum-sag and you will have all the bit's and pieces you want to take with you.

Tandem towing's easy-peasy. As for the legalities, as long as the combined GVM of the trailer & van does not exceed the TARRE of your car, that takes care of that. The overall length of your rig must not exceed 21 m (from the front bumber of the car to the rear bumper of the trailer) and that will take care of that.

(Again the forum fellas gonna screech) never the less, it's a viable option that will address your issues of lightness on the steering - safety point... And correct it is.

Also BTW with good common sense, it is just as safe as only towing a caravan....

Any help......... Yet?

PHOTO Ask anyone, I'm the dumbest dude on the forum, me going up Naudes nek tandem towing and if dung daft & demented me can go there you can go just about anywhere....

Nog nooit so trein gesleep nie Warren, dit beteken net een ding, te veel word ingepak. Neef weet dat om luuks te kamp lekker is maar loer maar na die goete wat net saamry en kar se gat in die grond druk.

Neef die storie agter die storie van tandem sleep.

So heele klompie jaar terug, so op die forum voor die ander forum, waaruit die form gebore was, het iemand n pos geskryf hy't noodig om N sleepwa agter n boot (rubber duck) Sordwana te sleep, en advies daaroor te vra

Hy't gese hy gaan dit doen want dit was sy enigste uitweg.

Ek't voorheen presies die sefde ding gedoen, met n 3.8 Impact rubber duck, 40Pk Suzukie outboard, en seevaardig (skipper's licence tot by 1 nauticle mile) en moes die "do it and learn" maneer geleer hoe.... Daaai tyd was daar nie forums nie..., And I learnt very quickly from my mistakes...

Lank storie kort, in plaas laat mense hom die regte advies gegee, die "kenners"  Jy weet daai "kenners" in plaas dat hulle vir hom reg hulp, het hulle gese... jy kan dit nie doen, dis onveilig moenie..... blah blah blah,

Die skrywer gaan dit doen...... Nou, plaas hulle hom die regte gids lyne gegee. se hulle bloot eenvallig moenie, en bly stil..... 

Toe klim ek daar tussen in en vir die ou so veel van my klein bietjie ondervinding gee (basies wat ek hier-boe geplaas)

Toe val die "kenners" my aan... (Plaas dat hulle erken dat as U dit reg aanpak, is dit heel doenbaar, hulle moes mos hulle standpunt verdeedig)....

Jy weet hoe die dinge aangaan, hoe meer jy iets se, hoe meer hulle jou aanpak, net soos kinders oppi skool speelveldt...

maar nou ja, ek weet wat ek weet....

Toe raak ek nou gatvol met die "kenners"wat so aanhoudend my probeer uitvat oor die storie, en om dinge te BEWYS het ek nou daai trippie gedoen, en plaas ek nou van JHB Umtentwenie to N3 af, het ek Wes on Lesotho gegaan, Joubert's pas / Naudes nek pas / Moordenaars nek pas / en met die opgaan Lang's nek by Majuba somme vir die laaste spyker gedoen.

Dit het my klein vinger laat krul van die lekkergeid to ek nou terug was en die heele trippi gesplash oor die forum.... Ook nou lekker aangegaan daar-oor...

Die "kenners"? Nooit die guts gehad om te se Ooops....

Wildehont

Just giving some options I'm aware of out, without trying to influence you in any one specific direction, or to say do this or do that, even shy-ing away from asking you to post your

packing list! , because each person does what they do because that's the way they enjoy themselves.

And, although single my whole life, I've kinda picked up that "keeping the missus happy" is vitally important to a "happy camper".......

Give you an example... Once at Mtinzini, one fella arrived with an office water cooler.... Now that for me was just "over the top" and I had a lot to say about it...

Ooops, what he did was use mix-up orange juice and saved ton's of money on fizzy coldrinks, for his 2 teenage kids and 2 friends the kids brought with!...

Brilliant!... And so we learn. So, just putting ideas out...

Glad your'e on your way

RGDS

W

Môre Chris

Ek het so vlugtig jou treurmare deurgelees.

Die vraag is; sukkel jy net met die sypaadjie/oprit, of is jou hele sleepkombinasie uit balans met jou hak gedeelte total te lag?

As jy net sukkel by jou huis oprit, koop 'n sakkie "ready mix" sement en verander bloot die hoek tussen straat en jou oprit. Dit faan 'n veel goedkoper oplossing wees.

Groete