I am looking into getting a suspensions for my truck this spring and really leaning towards a set up from Dobinson. But looking at pictures I can't help but notice how many more coils they have vs other systems. My concern is not having much up travel before coil bind, it just doesn't look like there is much space in the spring to allow for up travel. Wondering what everyone's thoughts are?
Dobinson system
Icon system for comparison (I know this is a much different system but just an example of other coil springs)
Spring bind will occur sooner with the tightly wound. But, do you have enough suspension travel to cause spring bind?
Spring rate is a combination of wire thickness and the number of coils - more coils means a softer spring.
The tight coils above sure will have a coil bind problem IF you have enough travel to get there like Vajingo said. I'm going to go out on a limb and say the Icon setup is a longer travel design.
The coil bind length of the springs may not be the limiting factor. How much available stroke does the shock have? A proper system should have the suspension bottoming out on a bump stop before the shock bottoms out or the spring gets to coil bind.
Vajingo said:
Spring bind will occur sooner with the tightly wound. But, do you have enough suspension travel to cause spring bind?
well this is what I'm trying to figure out really. Looking at the picture (and from the comment made by the guy that took it) there's about 1/4" or 3/8" gap between each coil so with 10 spaces that's 2.5" to 3.5" of up travel. That doesn't seem like much for a tundra. Am I thinking about this all wrong?
dps214
HalfDork
3/4/21 2:37 p.m.
80sFast said:
Vajingo said:
Spring bind will occur sooner with the tightly wound. But, do you have enough suspension travel to cause spring bind?
well this is what I'm trying to figure out really. Looking at the picture (and from the comment made by the guy that took it) there's about 1/4" or 3/8" gap between each coil so with 10 spaces that's 2.5" to 3.5" of up travel. That doesn't seem like much for a tundra. Am I thinking about this all wrong?
It's not a strut, so you have to consider motion ratio. From that picture if the spring has 3" of travel that probably equates to ~5" at the wheel which isn't a ton but is certainly more.
Also worth noting about the two photos from the original post, the second one appears to have the wheel off which means the spring is uncompressed so that's not a direct comparison.
In reply to 80sFast :
That's 2.5-3.5" on an inclined shock, so there would be more vertical movement of the wheel and then, you still have the motion ratio of the suspension arm to factor in. The wheel can probably move close to double the distance.
Edit: I could have been first with the motion ratio stuff if I could type with multiple fingers.
More coils needs thicker wire for the same rate, making the spring as a whole heavier, but since each coil has less total twist required as the suspension moves, cheaper, lower-grade steel can be used.
I'm using some Bilstein shocks from a 2003 Tundra in my Challenge build and they're slightly less stroke length than NB Miata shocks. Just cuz it's a truck doesn't mean the shocks actually need a lot of stroke.
Okay, this is all making me feel better. I just had images of me hitting every pothole in Michigan and loosing my teeth. I don't need a long travel setup, but don't want to buy a harsh crappy product either.
You can see how close the coils are in a TRD Tundra spring and they're at full extension.
In reply to DeadSkunk (Warren) :
You have a thread on the challenge build?
In reply to DeadSkunk (Warren) :
Miatas also have a remarkable amount of suspension travel. That's part of why they work so well.
Tighter coils = a longer spring
A longer spring is more supple.
In reply to bentwrench :
Well that's good, my big thing is I want a better riding leveled truck with a little bigger tires.
In reply to DeadSkunk (Warren) :
That's really cool in a "hope he's got life insurance" kinda way!
In that picture, it looks like you have 10 coil voids, each one at about 1". That's 10" of spring compression, and since the spring is inboard about half way on the LCA, that's 20" of compression at the wheel.
I think it will be plenty :)
Pete. (l33t FS) said:
In reply to DeadSkunk (Warren) :
Miatas also have a remarkable amount of suspension travel. That's part of why they work so well.
Well, Miatas made after 2005 anyhow ;)
Any thoughts on the suspension system I'm looking at? I will just be getting the shocks and coils and not the rear leafs (don't want to lift the rear). Dobinson seems to have a great rep, but wondering what everyones feeling were here about the setup.
Dobinson seems to be well-regarded for Toyotas. What're your goals here? I'd probably wouldn't use their shocks and get some Foxes instead, if that's in budget. Fox make really nice stuff.
Use will be daily driver/overloading. Main goal is a smooth ride over two tracks and around town. Nothing high speed. I considers Fox shocks (and some others) but I liked that the Dobinson IMS system was a 2.5" shock with rubber bushings. It seems all other 2.5" have solid bushings.
Being my daily I was worried the solid bushing would be harsher/noisier. Anyone have experience with this?
Solid bushings are probably not an issue. I dd-ed the Jeep with spherical bearings top and bottom in the front shocks and for the lower mounts in the rears for years. Couldn't really pick out a significant difference from the old rubber bushings when I first put them in. There's enough other noise in most vehicles than the little bit that comes through the shocks just isn't all that noticeable. And a lot gets lost inside the shock anyway.
Of all the systems I looked at it came down to Dobinson IMS, Icon 2.5" (non adjustable & no reservoir), and Ironman pro foam cell. Ruled out the Ironman kit because I'm not real comfortable with the foam technology and the green coil color isn't for me. The foam cell technology might be good and plenty of people seem to like their kit, but the tech of Dobinson and Icon are proven.
I put the Dobinson ($1,400) ahead of Icons ($2,200) because of price and bushing style. Icons aren't out of my price range, but I'm not sure for my use if the extra $800 is well spent on the Icons. Stage two of my suspension will be custom leafs (thinking Alcan), new bump stops, and UCA. My goals for the suspension are to 1) Have stock payload/towing capabilities 2) be durable 3) improve ride on crappy paved roads, dirt roads, and trails 4) increase travel/flex a bit 5) level the front and keep the back stock height.
