Desert/Trail Suspension and Tire Sizes

[FirstTimer67]

I'm looking to build a suspension that can handle mountain trails, desert washboards, and still cruise around the beach with the top off. Current setup is 1.5" SL, 2" BL, and 33" tires and I'm pretty happy with the look. I've been working with the guys at Duff and like the HiHo Silver system (because it includes the extended radius arms) but not so sure about raising overall ride height by 3" and having to switch to 35" tires. My concern is what that means for drivability, center of gravity, etc. when running through the desert at moderately high speeds and maybe no longer fitting in my unfortunately low ceiling garage.

Is anyone else running a similar setup in the desert? Money is a consideration but not the driving factor. I just don't want to have any regrets when trying to keep up.

 

[BanditBronco]

Technically, the ride is dictated by the spring rates as well as the shock damping. The two need to work together, and the better they do, the faster/safer you can go. I don't think you need to change the height of your Bronco to make high speed trail running a priority. Even just airing down the tires to 12-15 psi if you aren't already will make a substantial difference. The only benefit for you on a different style radius arm would be possibly a smoother transfer of linear travel going from a bushing style frame pivot to a rod end/hiem joint pivot. Possibly the ability to gain some down travel as well. You will most likely be limited by your driveshaft angle first and spring extension second, a stock bronco allows for roughly 8" of front suspension travel and about the same in the rear if you are using the stock shock mounting locations. No matter the height of your rig, you should be able to squeeze a few inches of usable travel out of both ends with some shock mounting changes. More with different radius arms. For the style of driving you are speaking of, a well damped 10" is plenty to have a good time. If it were me, I would put my money towards shocks, and correctly mounting them. That is assuming you have a newer lift on your Bronco with decent coil springs, any of our Bronco venders are solid, I don't think you would tell a difference between the brands unless one is linear, and the other is progressive. Same goes for leaf springs.

 

[toddz69]

X2 on what BanditBronco said. My Bronco currently has about the exact configuration you mention in your post (with some 6" longer radius arms) and very few people drive their Broncos in the desert more than I do (or mountain trails for that matter). Considering the limitations of the vehicle, it works reasonably well. If you do decide to go with extended radius arms, the Solo Motorsports arms are nice and don't have the lift limitations that the Duff arms do.

Todd Z.

 

[FirstTimer67]

This is great info guys, thank you. The existing lift is probably 20+ years old so it's getting replaced no matter what. Everything I've read/heard has led me to wanting the extended radius arms for desert which then led me to Duff which then led me to the HiHo Silver system, but the increased ride height is the root of my hesitation. Based on Todd's rig, it sounds like the extra length helps?

Bandit, when you say correctly mounting the shocks, does that mean changing angles? Or taller towers in the stock location to allow for longer shocks?

Todd, any idea what it is about the Solo arms that doesn't have the same limitation as the Duff. Is it extra length? Or is the pivot mount dropped down some to change the angle altogether? The Duff site says the extended arms require a 2.5" SL (I'm not opposed to the extra 1" vs current) but that heavy use should be 3.5"+. Not sure if my application constitutes heavy use, or if bump stops (possible air?) could be used to absorb impact before the radius arms hit the frame.

 

[toddz69]

The difference between the Solo and Duff's arms are that the Solos mount a little lower off the frame (I think) and the centerline of the arms still intersects the centerline of the radius arm cap area and isn't raised like the Duff setup. So the arm is essentially a little lower and doesn't hit the frame with smaller lifts like the Duff arms will - only a concern for those of us with small lifts. I have a video on my phone showing the travel of the Solo arms and they don't hit the frame even when the axle comes up solid to the frame w/o bumpstops in place. The Duff arms have an extra set of bushings in them aft of the C-bushings so they probably will aid in articulation a little more than the Solo pieces. I think they're also cheaper than the Solo pieces.

The longer arms have plusses and minuses - one other reason I like them is that they have a smaller angle of attack to the ground on a lifted rig than stock arms, which can help with the ride.

Broncobowsher's post in this thread gives a good summary:

https://classicbroncos.com/forums/threads/long-radius-arm-pros-and-cons.269518/

Todd Z.

 

[BanditBronco]

This is great info guys, thank you. The existing lift is probably 20+ years old so it's getting replaced no matter what. Everything I've read/heard has led me to wanting the extended radius arms for desert which then led me to Duff which then led me to the HiHo Silver system, but the increased ride height is the root of my hesitation. Based on Todd's rig, it sounds like the extra length helps?

Bandit, when you say correctly mounting the shocks, does that mean changing angles? Or taller towers in the stock location to allow for longer shocks?

You are mostly correct, as far as angles go, the more straight up and down you can get them the better. Angling the shocks any way from 90 degree perpendicular to the ground technically changes how they damp and can make the same internal valving act softer or firmer depending on what angle they are at. Luckily, Broncos tend to favor straight up and down mounting solutions anyway.

I was definitely speaking more towards taller mounting solutions to allow for longer shocks.

I have built very similar rigs with both Duff arms and solo arms. As Todd said, we were limited on up travel due to the arm contacting the bottom of the frame with Duffs. Nothing to shake a stick at, we were basically at our track bar to oil pan clearance limit at that point as well. With the Solo arms, you can get them to go as high as you want until you will start to run into basically everything else that you can, like the crossmember, oil pan, track bar mount, binding of the coils, etc.