Outer Limits 4x4 Board

Ok whats our rules update now?
At last count it was mostly sorted..... but lets clarify it with an update:



Tyre size: Rim size:
Maximum weight:
Maximum length:
Maximum wheelbase:
Allowed engine types:
Maximum engine capacity: Max # of cylinders:
Forced Induction: Two strokes:
Drivetrain options:
Suspension allowed:
Steering:
Brakes:
Safety equipment:

OK here goes

This is an entry level class compared to it's big brother and a buggy (if you use your head) can be built for less than $5000.

As for fabrication, you'll have to do this regardless of most competition classes because you need roll over protection in most classes. I'll clarify in my next post but you can just get the "A" and "B" pillars bent up and weld them in youself. By the way this we didn't come up with this idea to get someone else to build it for us and just drive. It's as much about getting people to come up with new ideas within a few guidelines as it is to drive the buggy itself. It will draw a lot of spectators because there will be such a wide variety of designs. After we get a few buggies together we can see about further rules to allow different forms of drive or suspension.

As for the IFS/IRS, why don't people think about different ways for this to work and do some research instead of being scared of something a bit different and burying yourself in convention. Having this as a rule won't make it anymore expensive and if people actually read all the posts then you would see that I've already answered most questions in relation to rules etc. You'd also see that we haven't even built one of these buggies yet so until we do we won't be able to finalise the guidelines and I (and others) think that if we leave the rules fairly loose then we can see what works and what doesn't and go from there.

We haven't ruled out electical and hydro drive but we have no way of regulating these against normal engines at this stage. (remember we haven't built one yet)

I've been checking specks of some cheaper chinese 4x4 atv/quad bikes, just to get some idea of dimensions/weights etc. They appear to be about 7' long by a bit under 4' wide, so it gives you some idea of what we are working with size wise, we need to be sitting where the motor is & put the motor & drivetrain somewhere else. they weigh in around 350 to 400 kg dry, now I know we could make them heaps lighter by getting rid of all the crap we wont need off them, but we still have to build a full cage. Anyway it's just food for thought for those tring to imagine how big the size would be.
cheers.

Give us 4 weeks to get a rough price on the bare chassis...If tiny is keen he might be able to bend up a generic DIY chassis at cheap? we could do similar up here for the northern qld guys.

I almost had the lates design rules written but lost them. Give me a bit there are some changes for the better and there are other things that we have reasons not to change. Give me another 20min it will all become clear as mud

toughnut wrote:I almost had the lates design rules written but lost them. Give me a bit there are some changes for the better and there are other things that we have reasons not to change. Give me another 20min it will all become clear as mud

Times up

I liked rock monkey zook class idea, would certainly be cheap and simple build, maybe the werock could take up this idea?
Sounds like you guys want a "quad" based buggy class.... if it were 2wd would be cheap class but 4x4 will complicate things, 4x4 quad parts are neither cheap nor common- any suggestions for cheap front drive systems?
An idea I have is using 2 complete trail bikes (pref old motorcrossers) building a frame to connect them together side by side with seat in between.
Link the tops of the front forks with steering rod and then you have a 2wd buggy with selectable rear drive, 4 wheel independant brakes, 12" - 14" wheel travel each corner, IFS, IRS with already sorted spring rates (and adjustable on any shocks newer than 1982)- hey I'm getting more excited as I write this!
Most of the frame is alreay done (the two bike frames) with only some simple hoops required to complete the roll over structure.
Building the front wheel drive system is up to however you guys think you are gonna do it (maybe lock the steering and skid steer like bobcats/ excavators).
Having two engines is no big deal to control, as mentioned maybe simplify steering.

slosh wrote:I liked rock monkey zook class idea, would certainly be cheap and simple build, maybe the werock could take up this idea?
Sounds like you guys want a "quad" based buggy class.... if it were 2wd would be cheap class but 4x4 will complicate things, 4x4 quad parts are neither cheap nor common- any suggestions for cheap front drive systems?
An idea I have is using 2 complete trail bikes (pref old motorcrossers) building a frame to connect them together side by side with seat in between.
Link the tops of the front forks with steering rod and then you have a 2wd buggy with selectable rear drive, 4 wheel independant brakes, 12" - 14" wheel travel each corner, IFS, IRS with already sorted spring rates (and adjustable on any shocks newer than 1982)- hey I'm getting more excited as I write this!
Most of the frame is alreay done (the two bike frames) with only some simple hoops required to complete the roll over structure.
Building the front wheel drive system is up to however you guys think you are gonna do it (maybe lock the steering and skid steer like bobcats/ excavators).
Having two engines is no big deal to control, as mentioned maybe simplify steering.

There are already classes that cater for this and it won't be any cheaper as you will still have to fabricate a lot of items. Especially safety items such as roll over protection. I've come up with some specs and as far as I can see the only thing that a few people will have trouble with is bending tube for the "A" and "B" pillars. Other than this you can use all straight sections. Next post are the latest rules

Lil Rock design rules: So Far lol

Max length 2500mm

Max width 1300mm

Max tire diameter 27 inches, type is open

Max tire width 12 inches, type is open

Rims open may be more than one rim per corner but total tire size must not exceed allowed dimensions

Max engine capacity 400cc, may be bonus for smaller engines, type is open. Must be naturally aspirated and internal combustion.

Max weight 500kgmay change once we actually have one built

Steering must be mechanical 4ws allowed must use steering wheel

Suspension IFS, must not be adjustable during a stage. Rear suspension is free

Drive train Must have a chain/belt link (somewhere) between engine and wheels and must be at least 2wd

Final drive must be mechanical

Brakes must have at least 1 disc or drum type brake

Fuel must be normal pump fuel. No race specific fuel

SAFETY and Chassis

Chassis must consist of 2 rails at least 400mm apart measured from the inside edge. Rails must be 40mm x 40mm box section or 38mm tubewith at least 3mm wall thickness. The rails must be joined at each end and at least 1 centre cross member of the same dimensions. The chassis must run the full length of the cockpit section. I.e. The length of the driver.Does not need to run the full length of frame. There must be a 5mm diameter inspection hole drilled into the chassis and easily accessed

Roll over protection Must consist of at least an “A” pillar and “B” pillar of no less than 38mm OD tube with a wall thickness of no less than 3mm and be welded directly to the chassis. “A” and “B” pillar must be spaced 500mm apart with the “B” pillar level with the rear most edge of the seat. The “A” and “B” pillar must be joined at the upper, most outer edge by tube of the same dimensions. “B” pillar must have be braced diagonally both laterally and fore/aft. Fore/aft bracing must be no less than 20mm OD and no less than 2mm wall thickness. This will in effect create a 6 point cage.

Other frame specs Must have a “hip” rail running at least 300mm above the chassis and above the level of the hip bone of the driver. The hip rail must run the full length of the cockpit section. All tube used on the frame, outside the above mentioned roll over protection must use no less than 20mm OD and 2mm wall thickness. Metal used as brackets for fittings may be of various sizes.

Cockpit protection Must have a firewall between the engine and driver of at least 2mm steel or 3mm alloy, regardless of type. All components driven by the engine (i.e. Drive shafts or chains) must be covered in the same way.

Buggy skin Must cover the frame below the hip rail with no gaps and must be of at least 1.6mm steel, 2mm alloy or 3mm plastic

Roof Must be removable and must be no less than 2mm steel mesh or 3mm alloy mesh.

Window areas (side) Must be covered by window netting that is secured but can be remove from both inside and outside the vehicle from the top rail to the hip rail with no larger than 30mm x 30mm holes and must be unobscured from both inside and outside.

Seat Must be secure and serviceable car or go cart type seat

Seatbelt Must be a minimum of 4 point harness securely fitted to the frame and no less than 50mm wide. Belts will have no frays or be stained by oil or other substances.

Engine cutout switch Must be situated at the rear of the cockpit in easy reach of safety marshals. Driver must also have control over engine cutoff

At least 1 x .9kg drychem fire extinguisher must be carried in the cockpit of the buggy and must be in easy reach of the driver.

This is it so far I know I’ve forgotten some things so let me know and I’ll update. This
will be the only post with the rules so if there are any changes I’ll highlight them.

P.S. These are only the design rules, not the competition rules. These will be based loosely on current rock crawling rules with some minor changes to try and help develop junior drivers. That is probably for another thread

would rather see wrist restraints and thick fabric mesh used

MADZUKI wrote:would rather see wrist restraints and thick fabric mesh used

Thinking more of protecting the driver agains intrusion rather than flailing injuries. Most people on here would like their kids to get into this. It'll also promote the team effort between driver and spotter as the driver will have less vision.

toughnut wrote:

slosh wrote: An idea I have is using 2 complete trail bikes (pref old motorcrossers) building a frame to connect them together side by side with seat in between.

There are already classes that cater for this

You have got to be kidding! I have never seen anything like I have described.

slosh wrote:

toughnut wrote:

slosh wrote: An idea I have is using 2 complete trail bikes (pref old motorcrossers) building a frame to connect them together side by side with seat in between.

There are already classes that cater for this

You have got to be kidding! I have never seen anything like I have described.

Doesnt matter, this class wont be catering for it

im a 16 y.o and this sounds freaking cool. the aussie 4wd mud racing accosiationo have a junior class, 1 litre engine max etc, i was looking seriusly looking at doing that but now i have other ideas.

slosh wrote:

toughnut wrote:

slosh wrote: An idea I have is using 2 complete trail bikes (pref old motorcrossers) building a frame to connect them together side by side with seat in between.

There are already classes that cater for this

You have got to be kidding! I have never seen anything like I have described.

I meant zuk base buggy that r0ck_m0nkey seems to be pushing more towards.

MADZUKI wrote:

slosh wrote:

toughnut wrote:

slosh wrote: An idea I have is using 2 complete trail bikes (pref old motorcrossers) building a frame to connect them together side by side with seat in between.

There are already classes that cater for this

You have got to be kidding! I have never seen anything like I have described.

Doesnt matter, this class wont be catering for it

Ummm, what I have described will fit into toughnuts rules... 2 x 125cc motors, driver will sit very low between engines so there is a lot of side protection.
What is it going to be then? Innovation or just build something that looks like a rhino buggy?

slosh wrote:

MADZUKI wrote:

slosh wrote:

toughnut wrote:

slosh wrote: An idea I have is using 2 complete trail bikes (pref old motorcrossers) building a frame to connect them together side by side with seat in between.

There are already classes that cater for this

You have got to be kidding! I have never seen anything like I have described.

Doesnt matter, this class wont be catering for it

Ummm, what I have described will fit into toughnuts rules... 2 x 125cc motors, driver will sit very low between engines so there is a lot of side protection.
What is it going to be then? Innovation or just build something that looks like a rhino buggy?

what size front wheels you planning on running ?

slosh wrote:

MADZUKI wrote:

slosh wrote:

toughnut wrote:

slosh wrote: An idea I have is using 2 complete trail bikes (pref old motorcrossers) building a frame to connect them together side by side with seat in between.

There are already classes that cater for this

You have got to be kidding! I have never seen anything like I have described.

Doesnt matter, this class wont be catering for it

Ummm, what I have described will fit into toughnuts rules... 2 x 125cc motors, driver will sit very low between engines so there is a lot of side protection.
What is it going to be then? Innovation or just build something that looks like a rhino buggy?

Go for it. I'd love to see it. Just make sure that the safety aspects and other specs are inside the rules and you're gold It'd be interesting to see how your mesh dirt bikes for side protection are going to be removable.

MADZUKI wrote:what size front wheels you planning on running ?

Probably source some 4 or 5" wide rear motorbike tyres on 18" rims, whatever will fit between the front forks.

toughnut wrote:It'd be interesting to see how your mesh dirt bikes for side protection are going to be removable.

Side protection comes at a price. BTW I don't think I'll be building anything in a hurry.

slosh wrote:

toughnut wrote:It'd be interesting to see how your mesh dirt bikes for side protection are going to be removable.

Side protection comes at a price.

Not at the price of potentially killing or permanently injuring someone because you couldn't access the buggy from outside the vehicle.

I'm really not keen on the mesh idea... how would someone quickly and easily be pulled from the buggy in an incident, how would the kill switch be accessed form outside the vehicle?


I'd think that the usual plastic type curtain used in car based motorsport would be sufficient, so long as a race harness is used and a minimum distance from side for seat mounts.


Another safety thing thats so obvious we assumed it must be there.... must have a fire extinguisher accessable from inside the vehicle.

Beastmavster wrote:I'm really not keen on the mesh idea... how would someone quickly and easily be pulled from the buggy in an incident,

I understand the thoughts but I'm thinking of both the drivers limbs etc protruding from the buggy as well as rocks etc intruding inside the buggy and both mesh panels and the roof are removable

Beastmavster wrote:how would the kill switch be accessed form outside the vehicle?

Not sure where else to put it. At the back of the buggy I suppose and just have a choke cable to a knob or a lever inside the cab so the driver can use the kill switch as well. I run a similar setup in my comp truck.

Beastmavster wrote:Another safety thing thats so obvious we assumed it must be there.... must have a fire extinguisher accessable from inside the vehicle.

You could just have fire marshals spaced around the track or have the a fire marshal escort the vehicle around the track. The fire extinguisher could be larger and therefore more practicle

the 30ish mm wide mesh would be plenty, part of the track building can make sure large pointy rocks are not in the way of possible roll overs as well.

Fire ext'....Use both

toughnut wrote:

Beastmavster wrote:I'm really not keen on the mesh idea... how would someone quickly and easily be pulled from the buggy in an incident,

I understand the thoughts but I'm thinking of both the drivers limbs etc protruding from the buggy as well as rocks etc intruding inside the buggy and both mesh panels and the roof are removable

Beastmavster wrote:how would the kill switch be accessed form outside the vehicle?

Not sure where else to put it. At the back of the buggy I suppose and just have a choke cable to a knob or a lever inside the cab so the driver can use the kill switch as well. I run a similar setup in my comp truck.

Beastmavster wrote:Another safety thing thats so obvious we assumed it must be there.... must have a fire extinguisher accessable from inside the vehicle.

You could just have fire marshals spaced around the track or have the a fire marshal escort the vehicle around the track. The fire extinguisher could be larger and therefore more practicle

i really don't like the mesh either... rock intrusion doesn't appear to be a huge risk in werock, why would it be in this class (and you can design tracks so you don't go near the thin pointy rocks/trees)... access to driver/killswitch/extinguisher i'd say is a bigger concern than intrusion (make a minimum side profile with panels in the lower section "window" section covered by window net and use a wrist restraint.)

i'd say have both (marshal on course and vehicle mounted extinguisher). a marshal with an extinguisher can't move real quick, and if they are close, they will need to dodge buggies...

so the main rails have to be box section with turb for rollover protection? could we not run tube complete full frame?

Screwy_ScrewBall wrote:so the main rails have to be box section with turb for rollover protection? could we not run tube complete full frame?

Just trying to come up with an easy formula. If you make it a basic ladder frame with the roll over protection it sets an easy platform for people to work from even if they haven't built stuff like this before.

toughnut wrote:

Screwy_ScrewBall wrote:so the main rails have to be box section with turb for rollover protection? could we not run tube complete full frame?

Just trying to come up with an easy formula. If you make it a basic ladder frame with the roll over protection it sets an easy platform for people to work from even if they haven't built stuff like this before.

im just looking into options... if i was to look at building one of these for myself in the future i would prefer to run a tube complete ladder frame and chassis rather than box.

toughnut wrote:

Screwy_ScrewBall wrote:so the main rails have to be box section with turb for rollover protection? could we not run tube complete full frame?

Just trying to come up with an easy formula. If you make it a basic ladder frame with the roll over protection it sets an easy platform for people to work from even if they haven't built stuff like this before.

agree, box section chassis, 4 bends in total on 2 bits of tube is the only bit any mug with a welder and grinder cant do then

disagree that you need steel roof etc, roof neds to be covered but mech is fine, same with the sides, bit of plastic would be fine.

might get the old bikes into the workshop in the next few weeks and start on a frame

thinking some small hatch type CVs for the drive off a sprocket mounted with two bearings, one either side with brass bushing to space it right ??? i think keep is simple stooopid is the right formula

with the suspension, I am lost as to come up with a double boxed arm or similar to keep the wheel strightt or if a fixed wheel with the chassis mount hinged would be better....probably simpler