Ranger/BT50 Stage 1 Mid-travel Rear Spring kit
4 available
Forget what you know about aftermarket leaf spring kits, the G.O.A.T Offroad Stage 1 rear kit blows everything else out of the water for comfort, control, and performance.
The core of this kit is our engineered bolt-on solution to convert the rear leaf springs from sprung over to spring under axle.
This conversion allows us to fit our own custom-designed and Australian-made, long-travel leaf pack. Having the springs under the axle means that we can fit a much longer leaf pack, with a huge amount of camber. We also use thinner individual leaves, meaning there are more leaves per pack allowing each leaf to flex more than your traditional thicker leaves.
The leaf springs feature a military wrap design, diamond cut ends for increased durability, anti-friction pads at each end, and high-quality keepers. Available in multiple spring weights to suit your own setup.
What this all means, in conjunction with our unique shackle, is that your leaf pack actually works, providing a much more linear spring rate and increased control and comfort at all speeds, whether it's crawling up a tough track or hitting the corrugations on some of those remote touring trips through the middle of this big country.
To make sure that when you do find the limit, we have designed a progressive triple rate bump stop, which will ensure that your shocks are protected from those hard hits and you don't feel like your axle is about to come through your chassis.
Q: Why spring under axle, doesn't it lower my ground clearance and wont the u-bolts get stuck on rocks?
A: Right where the leaf springs are mounted, yes, you will have technically less clearance. But, our design is pretty unique compared to common examples (Landcruiser 79 series) where we use square u-bolts from the bottom, with a leaf spring skid plate, which leaves no sharp edges to get caught on.
We believe the benefits of the much longer springs outweighs the small loss of ground clearance.
Q: Is there any welding required?
A: Nope. It's a complete bolt on system that is easily reversed if required.
Q: Is it road legal?
A: It's in a grey area. The lift is below the NCOP limit, so it doesn't breach that. The conversion shackle is technically longer than factory, but its to suit the change of spring location. Consult with your state authority for clarification.
Q: Which shocks should I pick?
A: Depends on your goals. For us ride comfort is the number one priority and that means balancing uptravel with down travel.
So, first we need to look at the factory shock specs. Open length is 618mm and closed is 378mm for a very respectable travel of 240mm.
Using some simple math, if our new ride height is approximately 38-50mm taller than factory, the replacement shocks ideal closed length would be around 410-420mm.
The goal is to get as short of a closed length as possible whilst also having a long open length...but we are still bound by the laws of physics, so as your open length gets longer, so does your closed length.
For us the sweet spot is around 10-11inch travel shocks. You can of course fit longer and sacrifice your uptravel for more fully sick flex.
The other thing to consider is the bump stop. Our included bump stop has been set at a height that works for shocks between 410-430mm closed length.
At the end of the day the choice is yours.
| Open | Closed | |
| Superior 40mm Gas - 10in travel | 680mm | 420mm |
| Superior 40mm Gas - 10.5in travel | 700mm | 430mm |
| Superior 40mm Gas - 11.5in travel | 735mm | 443mm |
| Superior 2.0 Remote Res - 10.5in travel | 680mm | 415mm |
| Superior 2.0 Remote Res - 11in travel | 700mm | 425mm |
| Superior 2.0 Remote Res - 11.5in travel | 735mm | 445mm |
Please note: 2.0 Remote Res shocks will require PSR P/n PSRUNI-088 X2 to convert remote res to piggybacks.
Specs
- Approx 40mm lift
- Up to 12" wheel travel (depending on shocks)
| Spring Rate | Constant weight | Max Weight | |
| Performance 0-150kg | 170lbs/in | >50kg | 150kg |
| Medium Duty 150-300kg | 200lbs/in | 100-150kg | 300kg |
| Heavy Duty 300-450kg | 230lbs/in | 200-270kg | 450kg |
| Ultra Heavy Duty 450-600kg | 294lbs/in | 400-450kg | 600kg |
Before purchasing, we HIGHLY recommend you going to a weigh bridge, with the setup that you drive around with 80% of the time and then working out how much additional is over the back axle compared to stock then picking a spring pack to suit this weight.
Our kits are biased towards performance and not towards load carrying. If your truck regularly see's large changes in loads, we recommend other leaf spring products would be better suited.
We will also have a specific Airbag kit in conjunction with Boss Airbags which will help with large load variances.
Whats included
- Our proprietary engineered spring under axle conversion sytem
- G.O.A.T Offroad custom leaf pack
- Beefy conversion shackles
- High performance 2 stage poly bumpstop
- 4x U bolts
- Leaf and Shackle bushes
- All required hardware
Whats NOT included
- Shocks!
We highly recommend running a 2.5 diameter adjustable shock with reservoir for optimum performance and dampening. Length should be around 2" longer up to 4" longer. If you go for a really long shock, you will need to space your bump stop up.
Our shock preferences.
- GMF4x4 Race - Link
- King 2.5 - Link
- Fox 2.5 - Link
- Dobinsons MRA - Link
- Profender/Superior 2.5 - Link
Additional Recommended Parts
To round out the supsnesion package of your Ford Ranger or Mazda BT50 we recommend pairing our stage one with a 2.5 diameter front shock and aftermarket upper control arms.