'17 TRD Pro - coil spring question

Throwing this out there, but I understand that the Bilstein has some machined grooves in the shock body to allow you to move the circlip up or down to adjust/account for sag etc. I'm wondering if one could do the same w/ the Fox front shocks? You'll have down time to have it sent out to get that groove machined but might be another option...albeit a more cumbersome route than using a 1/2" spacer

it's too bad that you can't get an aftermarket stiffer spring from Fox

 

A snapped a few pics today as it stands . . .

 

Really looks good to me. Assuming you'll have additional weight in the back, it might be ok as is? You don't wanna load up the back and be sitting nose high. I'd prefer to even have a little rake left when loaded so you're not hitting the bump stops on bumps. But maybe that's not an issue for you.

 

another thought and might be a little cheaper than changing out the entire Pro suspension, what if you just bought the Fox 2.5 aftermarket front struts and springs. That'll give you the flexibility (a bit more height) that you want.

 

I’m in exactly the OP, identical truck, similar bumper/winch combo. I also have full steel skids, sliders, so even heavier all around. First of all, thanks to the OP for tracking down details on the trd pro stock spring rate, 550 lbs. feels like the correct number.

Some notes from my own research on suspensions, fwiw:

* Springs are linear. So preload should not affect ride quality. A 550 lbs spring will compress 1” for every 550 lbs of load, no matter if that’s the first in. of compression or the last.
* preload will decrease the amount of travel available for the spring to compress. Too much preload and you could get binding, which is when the coils touch together, and which is a bad thing.
* not sure what the “coil spacers” mentioned are, even with links provided (maybe I need to scroll around more?). A traditional spacer sitting on top of the shock will give lift, but not add travel. No real improvement to me.
* it’s probably true that the shocks on our coil overs are tuned to the stock spring rate, and changing the rate will change ride characteristics. How much change for a 100 lbs rate increase? No idea.

Personally, with all that in mind I originally thought I might try a spring swap and see if I like the ride. I haven’t found off the shelf springs guaranteed to fit our shocks, however.

These days I started considering just writing off the extra cost of pro suspension as “R&D”, and doing a full upgrade to kings mid-travel and take advantage of the added travel, external reservoir, and on the fly adjustability.

Just my 2c.

 

I have no experience with these, maybe someone else has?? Came across them when I was buying sumosprings to help out my rear end when loaded. At $115, it might be worth a try?

https://www.supersprings.com/shop/CSS-1094

https://www.youtube.com/watch?v=LLmbsPrDltE

 

But EVERYONE says preload does affect ride quality.... what's the story here?

 

I'm pretty sure the top coil spacer from @HeadStrong Off-Road would work well for you. pretty cheap, easy to install. Hit up Marie and they can help you. Great service, great price.

 

That’s true that lots of people say that. All I know is that springs are linear. F = kX, F is force on the spring, k is the constant rate, and X the deformation. There are springs with multiple rates, where they will behave as a single linear spring until they don’t, but I don believe our coils are like that. I think our leaf springs fit that multiple rate model.

 

This seems like it wouldn’t stay in place for long off-road. Then it would hang by the zip ties around the suspension components. So it doesn’t look like a long term solution to me.

 

Thanks for weighing in Penguin-

I know most here will say the TRD Pro package is “more show than go” but when I spoke to what seemed like a very knowledgeable rep at Fox I gave him plenty of room to tell me the best thing to do to solve this issue would be to swap out the whole suspension- he was quick to tell me I’d have to go a very long way before reaching the caliber of what they put on there and “tuned” for the Pro. I’m not going to die on the hill trying to defend that, but it’s what he said. He’s the one that gave me the 550lb spring rate. He’s also the one who recommended the pre-load spacer (but definelty not a top plate spacer) and he was only comfortable to recommend that given my realistic approach to mitigate a small amount of drop from the added weight. Generally against spacers, he was clear he didn’t want to go on record for Fox, but personally to him seemed like a good solution given the application. I didn’t take good notes when I spoke with him but I believe his justification was similar to the points you made above. He was firmly against the top plate style spacer. I didn’t probe into the why and assumed for all the other reasons I’ve read about here on the forums.

 

Also- I should of mentioned he wasn’t for swapping the spring for a stronger one - which going into it seemed to me like the proper way to do it. He felt that would have a greater impact on the whole system Fox impelemented on the truck and change the general dynamics. Again this is one 15 min conversation but I trusted the source.

 

Props to you for doing the legwork here and reaching out to those reps. The Polyurethane preload spacer you linked earlier could be a good solution, if it compresses when installed. Otherwise you’re preloading 1.25” on top of the sag you got with the extra weight, and that seems a bit much. For myself I see a full upgrade down the road, keeping in mind I think I’ve added more weight than you have.

 

Thank you so much @ahkouchi

 

Any headway on this?

 

Good question. I was close to trying the Daystar preload spacer, but opted not and weighing out options for suspension upgrade with lift. I think the challenge is bigger than the just the 1/2" in the front. While I believe the Fox suspension on the Pro is great, with bed rack, RTT, front bumper, winch, roof rack, etc. - the lack of lift and adjustability limits what I can add without negatively impacting ride height and likely overall performance. I've added roughly 200 lbs. to front and 300 lbs. to the rear. I didn't intend to add as much as I have but now I think an suspension upgrade is my best option. For the moment, I plan to pull the Pro suspension out and get as much for it as I can.

 

My exact concern. Feels kind of dumb to even think about changing this suspension out but dammit I want bumpers and sliders!

 

I bit the bullet and changed out the suspension - went with Icon. Will be selling the Fox Pro suspension. In the end it seemed like the right solution.

 

How much are you selling the PRO suspension for?

 

I don't have the requisite 50 posts to advertise them here but I'm going to go to work on that this week. I have not picked a price yet but I'm motivated to let them go