BP-51 issues

[KilaCruiser]

Just wanted to say - this was all super useful to me. Thanks!

 

[elkeye]

Just wanted to say - this was all super useful to me. Thanks!

FYI ...

2720 & 2721 have progressive spring rates
2722, 2723, 2724 & 2725 have straight or linear spring rates.

See Page 175 of the OEM Application Guide.

ARB 4x4 Accessories - Old Man Emu International Application Catalogue | Edition 51 - Page 1

INTERNATIONAL Application Catalogue Number 51 | December 2022

view.publitas.com

 

[sleepintheback]

FYI ...

2720 & 2721 have progressive spring rates
2722, 2723, 2724 & 2725 have straight or linear spring rates.

See Page 175 of the OEM Application Guide.

ARB 4x4 Accessories - Old Man Emu International Application Catalogue | Edition 51 - Page 1

INTERNATIONAL Application Catalogue Number 51 | December 2022

view.publitas.com

Thank you for the handy info. I'm concerned that swapping from the 2722 to the 2721 won't make a huge difference. The stock spring rate is 170,
2722 spring rate is 275
2721 spring rate is 270/350
So at small amount of compression, which is where the suspension lives on the road, there's only 5 lb/in difference between the 2721 and 2722. This is only 1.8% less force!
Either of these options is still (270-170)/170*100= 59% stiffer than the OE spring rate at small deflections!
I certainly didn't make my truck 59% heavier in the back, so it's no wonder this thing rides like an unladen work truck.
Is there any option to go back to something nearer a stock spring rate, that is still compatible with the BP51 dampers I have fitted?
Perhaps I'm not understanding correctly how a progressive spring behaves? I assume it starts out at 270 lb/in, and by the time it's near full compression the rate is 350 lb/in.

 

[Fishinsea]

I have the BP-51 on my 2018 LC set at 2" with the 2722 rear springs and am 100% happy with the ride after getting my compression and dampening set to my liking and once I get a rear bumper it will be magic. Install instructions were pretty good i thought, just my .02

 

[sleepintheback]

I have the BP-51 on my 2018 LC set at 2" with the 2722 rear springs and am 100% happy with the ride after getting my compression and dampening set to my liking and once I get a rear bumper it will be magic. Install instructions were pretty good i thought, just my .02

I'm glad its working out for you! Does your truck weigh substantially more than stock?
My aluminum skid plates added 55 pounds, my sliders are 120, and I have a rear bumper headed my way that weighs about 60. BUT, I took out the rear seats, so minus maybe 80 pounds. Overall, I'm only 155 lbs heavier than stock. That's like a skinny passenger! Maybe you've got some heavy accessories, like steel bumpers and skid plates?

 

[Fishinsea]

I'm glad its working out for you! Does your truck weigh substantially more than stock?
My aluminum skid plates added 55 pounds, my sliders are 120, and I have a rear bumper headed my way that weighs about 60. BUT, I took out the rear seats, so minus maybe 80 pounds. Overall, I'm only 155 lbs heavier than stock. That's like a skinny passenger! Maybe you've got some heavy accessories, like steel bumpers and skid plates?

I'm not that heavy, I have the ARB aluminum skids, 18x9 methods and 33.1 tires, Trail Taylor Hidden winch mount with 12k winch installed. Always have about 50 lbs of recovery gear in back and truck is kept full of fuel all the time, I find NO harshness what so ever, not even close, my rebound on rear is 4 and compression is 2 and my rear coils are 2722. I chose the 2722 because I will have a rear bumper in the near future and when I road trip I will have a few hundred pound in back. Have you put a few hundred pounds in the back yet ? when i picked up some decorative bagged rocks at Lowes say 350 pound worth it rode like it was on a pillow

 

[sleepintheback]

I'm not that heavy, I have the ARB aluminum skids, 18x9 methods and 33.1 tires, Trail Taylor Hidden winch mount with 12k winch installed. Always have about 50 lbs of recovery gear in back and truck is kept full of fuel all the time, I find NO harshness what so ever, not even close, my rebound on rear is 4 and compression is 2 and my rear coils are 2722. I chose the 2722 because I will have a rear bumper in the near future and when I road trip I will have a few hundred pound in back. Have you put a few hundred pounds in the back yet ? when i picked up some decorative bagged rocks at Lowes say 350 pound worth it rode like it was on a pillow

I come from a backpacking background, so every piece of gear I own cumulatively is probably around 100 pounds-and that's bringing doubles of a lot of stuff. The heaviest thing I've ever put in the cruiser is 7.5 gallons of water-a whopping 65 pounds. I don't like cold cuts or beer, so I don't usually even bring a cooler.
What you're saying about adding the gravel and the truck riding nice is how I want my truck to ride all the time. I think my use case is just outside of what this BP-51 setup was designed for. It'd be great if I had a load of kids and a cooler full of ice and drawers and a bunch of luggage. But it's just me, sometimes a companion, and maybe 50-100 pounds of stuff. One of my to-do projects on this is to delete the stock roof rack, and leave it off! I don't have so much stuff that I need to start strapping it on the roof.
I had a ford ranger, and it rode really nice with 1,000 pounds of gravel in the bed.
Your wheels and tires don't help mash down the springs, they're unsprung weight. Your shock absorbers have to keep those in check.

 

[Fishinsea]

I come from a backpacking background, so every piece of gear I own cumulatively is probably around 100 pounds-and that's bringing doubles of a lot of stuff. The heaviest thing I've ever put in the cruiser is 7.5 gallons of water-a whopping 65 pounds. I don't like cold cuts or beer, so I don't usually even bring a cooler.
What you're saying about adding the gravel and the truck riding nice is how I want my truck to ride all the time. I think my use case is just outside of what this BP-51 setup was designed for. It'd be great if I had a load of kids and a cooler full of ice and drawers and a bunch of luggage. But it's just me, sometimes a companion, and maybe 50-100 pounds of stuff. One of my to-do projects on this is to delete the stock roof rack, and leave it off! I don't have so much stuff that I need to start strapping it on the roof.
I had a ford ranger, and it rode really nice with 1,000 pounds of gravel in the bed.
Your wheels and tires don't help mash down the springs, they're unsprung weight. Your shock absorbers have to keep those in check.

I follow you, My background is a outfitter hunting guide use to crappy stiff as F-350 getting bounced around like a rag doll and I kinda like the frim tide, we all have our likes and dislikes. I'm glad I did it the way I did and didn't have to mess with changing things, its not that hard of a job to change out the rear springs so ur good there. I hope ya get it the way you want it bud, heres a shot of my ride

 

[sleepintheback]

I want mine back like it was with the stock setup. I might be able to get close enough by backing all the preload off the front coil overs, and going back to a stock spring with maybe a 20mm spacer.
There's my truck, I was impressed with how high it got up that dune.

 

[TheGrrrrr]

I want mine back like it was with the stock setup. I might be able to get close enough by backing all the preload off the front coil overs, and going back to a stock spring with maybe a 20mm spacer.
There's my truck, I was impressed with how high it got up that dune.

View attachment 2582117

Let me know if you want to get rid of the BP51s on your way back to a stock feeling ride.

 

[sleepintheback]

Let me know if you want to get rid of the BP51s on your way back to a stock feeling ride.

I'm keeping my eye out for a set of new-ish stock take-offs. What kind of a hit do you think I'd take selling my BP-51s less than 6 months old, a few thousand miles?

 

[TheGrrrrr]

I'm keeping my eye out for a set of new-ish stock take-offs. What kind of a hit do you think I'd take selling my BP-51s less than 6 months old, a few thousand miles?

You might get enough out of them to pay for a Bilstien setup... my guess is $1500. A year ago when there were fewer options, I would have said $1800 to $2000.

 

[lbcadvntr]

I would have recommended 2721. 2721’s are a progressive spring where the 2722’s are not. They will definitely ride differently. While you’re at it, check the pressures on your rear tires. Some shops wildly over-inflate...and if they did, that will only feel worse.

I would seriously consider going to the 21’s. They really are a winning go-to for most when at stock weight up to mild mods like full weight rock sliders and rear drawers, for example.

***If you decide to go ahead with BPs in front, and you’re at close to stock weight (no steel bumper/winch in front)...***make sure the shop does NOT leave the pre-load ring adjustment as it comes from the factory.** The factory *assumes you have a full build* and sets preload to 20mm downward on the preload threads. You will have a harsh ride if you leave it there because you don’t have the extra 300+ pounds on your front bumper. At stock front weight, you’ll want the preload ring backed off to about 5mm...not the factory default of 20.

Here’s a before/after...stock vs BP-51 with2721 coils and fronts installed.
View attachment 2441672

Hi Markuson, thanks for sharing your setup and especially the before and after pics!
I bought a 2013 not too long ago and it has BP-51 up front and what appears to be stock springs/shocks in rear.
I’m considering purchasing the rear OME rear springs and came across your post. Your ride looks sweet! I have a magnetic grey one too!
I’m getting to point where I need to swap rear shocks and Im thinking of going with the 2722 rear springs for a few reasons. 1. The 0.75” lift, 2. I often carry 4 mountain bikes on bike rack attached to hitch, and 3 I have a small trailer I take camping and dont want LC squating too much. Also I prefer the look of a truck with rear slightly higher than front (I think it’s called raked look?) I think yours sits about even or slightly lower in rear? Hard to tell from pics n driveway.
Did your rear 2721 settle? Now that you’ve had them on a while do you wish you had gone with 2722? How can you tell 2721 are progressive and 2722 are not (is that on OME page)? Did you pair the 2721 with the OME rear shocks?
TIA

 

[lbcadvntr]

I'm not that heavy, I have the ARB aluminum skids, 18x9 methods and 33.1 tires, Trail Taylor Hidden winch mount with 12k winch installed. Always have about 50 lbs of recovery gear in back and truck is kept full of fuel all the time, I find NO harshness what so ever, not even close, my rebound on rear is 4 and compression is 2 and my rear coils are 2722. I chose the 2722 because I will have a rear bumper in the near future and when I road trip I will have a few hundred pound in back. Have you put a few hundred pounds in the back yet ? when i picked up some decorative bagged rocks at Lowes say 350 pound worth it rode like it was on a pillow

Hi Fishnsea,
Sweet ride! The angle of pic is hard to tell but is you read slightly higher than front? My wife and I also prefer a stiffer ride. Before the LC we owned a Rubicon so the LC is way better ride but we just want it a little stiffer (more truck like) and we go out as a family and often carry a lot of gear in the rear.
Do you still have your LC? How’s the long term review?
TIA

 

[lbcadvntr]

I'm not that heavy, I have the ARB aluminum skids, 18x9 methods and 33.1 tires, Trail Taylor Hidden winch mount with 12k winch installed. Always have about 50 lbs of recovery gear in back and truck is kept full of fuel all the time, I find NO harshness what so ever, not even close, my rebound on rear is 4 and compression is 2 and my rear coils are 2722. I chose the 2722 because I will have a rear bumper in the near future and when I road trip I will have a few hundred pound in back. Have you put a few hundred pounds in the back yet ? when i picked up some decorative bagged rocks at Lowes say 350 pound worth it rode like it was on a pillow

What did you set the preload to up front? Did you set both driver and passenger side the same?

 

[lbcadvntr]

I would have recommended 2721. 2721’s are a progressive spring where the 2722’s are not. They will definitely ride differently. While you’re at it, check the pressures on your rear tires. Some shops wildly over-inflate...and if they did, that will only feel worse.

I would seriously consider going to the 21’s. They really are a winning go-to for most when at stock weight up to mild mods like full weight rock sliders and rear drawers, for example.

***If you decide to go ahead with BPs in front, and you’re at close to stock weight (no steel bumper/winch in front)...***make sure the shop does NOT leave the pre-load ring adjustment as it comes from the factory.** The factory *assumes you have a full build* and sets preload to 20mm downward on the preload threads. You will have a harsh ride if you leave it there because you don’t have the extra 300+ pounds on your front bumper. At stock front weight, you’ll want the preload ring backed off to about 5mm...not the factory default of 20.

Here’s a before/after...stock vs BP-51 with2721 coils and fronts installed.
View attachment 2441672

Did you set both driver and passenger side preload equally at 5mm?

 

[Markuson]

Did you set both driver and passenger side preload equally at 5mm?

I don't which measurement I was on at the time of this older post, but I definitely set them the same on both driver and passenger. Stock fuel tank sits toward passenger anyway…so you end up with some weight variation no matter what you do. I’ve never felt the need to vary preload between sides.

 

[lbcadvntr]

I don't which measurement I was on at the time of this older post, but I definitely set them the same on both driver and passenger. Stock fuel tank sits toward passenger anyway…so you end up with some weight variation no matter what you do. I’ve never felt the need to vary preload between sides.

Thanks for confirming
Did you install taller rear shock on passenger/gas tank side?

 

[Markuson]

Thanks for confirming
Did you install taller rear shock on passenger/gas tank side?

Taller spring goes on fuel tank side.
On US spec 200’s, the tank is on passenger.
So… the talker rear goes on passenger.