Brake dive

I don't understand why you think spring preload reduces brake dive. Its primary effect is to increase ride height and that is more likely to increase brake dive because of increased height of the center gravity of the truck.

Preload does not change the stiffness of the spring (aka its spring rate) if that is what leads you to believe it reduces brake dive.

 

Quite very hard if some dip on a cell phone not paying attention pulls out in front of me... If the truck is bouncing and getting squirrrely during that stop, I'd certainly want to fix that.
I never actually thought of brake dive as a problem when mine was stock, however once I put the Fox dampers on it, the greater control of brake dive and body roll dynamics was among the first things I noticed (after the greatly-improved ride). Again, shocks very much play a role in your vehicle's handling beyond just speeding through curves and/or racing down that desert trail.

 

Thats counter to my experience (I have owned SR5, OR, and King shocks) and my understanding of physics. I have to believe it's more likely due to that human nature that leads us to believe that money spent on a pretty object is money well spent. Have you ever read about blind wine tasting tests? They teach us in science education to resist that tendency and to focus instead on objectively, but it's still easy to fall into that trap.

 

lmao
Maybe you should try replacing your Kings with the OEM shocks you originally had on your truck (since you seem to think shocks don't matter so much). You'll quickly realize how good you had it with your Kings.

Which prompts the question, why did you even buy Kings for yours?

 

Why evidence do you have that I will notice such a great difference? Although a side by side test would be interesting today, I don't think I really need to because I already did it twice. I also drive around in other cars and trucks and notice little to no difference.

I bought Kings because I could afford them and I thought they would be awesome when driving at high speed off-road. Sadly they under impressed me. I have noticed slightly better handling when bombing down very rough roads and trails at high speed and slightly less porpoising when towing the boat. During daily driving I notice nothing. I have considered getting them re-tuned for more dedicated off-road use with the assumption that the factory tune is for on-road, but I haven't pulled the trigger. I would like to see actual damping curves from shock dynos, otherwise I don't feel like I know what I'm paying for.

I think people on this forum have a tendency to overestimate the effect of shock absorbers. They are only one part of a suspension and under simplified normal circumstances can be summed up by one number: their damping constant. A shock with a damping constant of 11 lb/ft/s does not necessarily cost more or preform better than one with 10 lb/ft/s, just like a spring with a constant of 700 lb/in is not necessarily more expensive or preform better than one with 600 lb/in. They are simply tuning parameters. A King shock tuned to the same damping constant is going to behave the same as a OEM shock tuned the same under normal circumstances.

A King shock differentiates itself with its ability to be tuned to a much higher (or lower) damping constant, ability to be tuned to non-linear damping curves, heat dissipation capacity, cavitation resistance, and other things that happen at loads much higher than occur during daily driving.

 

Ok... Good enough reason I suppose (and basically parallels why I bought my Foxes).

I bought mine from @AccuTune Offroad , and the difference was night vs day, soaking up bumps vs slamming the bump stops, being able to remove (and not miss) the swaybar vs truck flopping all over the place. Maybe the custom shock tune they do is part of it. I'd suggest hit them up and have them redo your Kings. The difference probably will again be night & day. And if it's not, then I don't know what else to tell you...Your experience does not match that of most people who buy high-end shocks.

 

Here we go again. College boy is back at it, if you have kings with a low speed adjustment go crank that sucker and tell me you don't notice i difference in the rate the front end drops.
If the shock slows the compression does it not make it take longer to hit that same point it would regularly hit? Therefore, any quick shot of the brakes would result in the front end staying higher longer. Now if you do a hard long brake would the ride height end up in the same place yes but it would happen slower greatly reducing the felt effects of brake dive.
Does a shock make it so the truck always sits higher no. But does it greatly impact the felt effects 200% and in short hits it will end up sitting higher as it takes longer to compress yup. So go ahead again and "fail" to educate us all.

 

To be clear, I never thought the King shocks were going to make much difference during daily driving, but I did think/hope they would make more difference during high speed off-road driving.

Also, after the purchase and installation excitement wore off (I installed them myself) , I realized I really don't have a lot of opportunity to drive fast. Most of the stuff I do is slow "rock crawling" sort of stuff.

 

If you drive your truck like you are at the track or a desert race course, I might understand your subjective perception. The way I drive, dive, lift, squat, and roll are nearly imperceptible.

You should also go back and read my posts where I describe steady state (static) and transient (dynamic) behavior. We're not really disagreeing on much. I think the disagreement I have with the populous is mostly about the definition of "brake dive", whether 2 different OEM replacement shocks make a noticeable difference to brake dive during daily driving, and whether there are better ways of attacking brake dive.

I wonder if we could devise a brake dive measurement experiment and compare results. It might be easiest done with an accelerometer as I think many people are associating brake dive with acceleration rather than displacement. You can also derive displacement from acceleration.

 

If only I still had my numbers from the old mountain bike days. It would well illustrate this. As it is much easier to test record and show the effects of low and high speed compression in that setting but all the principles are the same when considering the front suspension.
Does your truck still have a sway bar? If so pop it off then repeat the low speed compression experiment that will help really display what effect it has.

We used to have a far more primitive version of this. I really wish I was still as involved to take advantage of the new tech available.

https://www.pinkbike.com/news/review-byb-telemetry-2-mtb-data-acquisition.html

 

Mountain bikes are often ridden much more aggressively than a car is, thus dynamic effects are going to be more prominent. I agree with you there. However, personally as a former avid dirt biker and mountain biker, I was never concerned about brake dive in comparison to other suspension behavior. I was also never a big gear guy. I focused on increasing my skills and having fun.

 

Shocks definitely play a role in minimizing brake dive. My factory shocks have about 67k and are spongy AF.

 

The priciples of brake dive in a mountain bike application should of been a huge concern to you. How far into the travel a fork sits of the rate it g's out under slow compression has alot to do with maintained stability. If they are ridden more aggressive would that not in turn make the suspension performance more important and having data to base a tune off of would not in turn make you able to develop better skills so your not over compensating for a poor set up?
You sure seem to be all about data and proof but yet you do not offer anything that is a direct notion stating it does nothing. No side by side tests just a lesson in geometry that does not factor in any of these outside variables.
These people have noticed felt effects by changing dampers and based off what these specific dampers valving profile is and my experience with how drastic the effect a damper has on suspension performance I fully believe them. Why can't they just enjoy their mod and have fun without someone on the internet going nope your wrong.

Yes you may not notice it as much on your kings with their progressive valving which would feel soft in immediate stroke compared to a 5100 with digressive valving.

I drove buddies off road with an ome set up and the thing had an identical spring rate and front end weight and it felt like it was on rails on road compared to the absolute boat mine is like but it drives like a dump truck on gravel roads compared to mine which floats down service roads. Huge difference in felt brake dive between the 2 trucks.

Rather than playing on paper and going with theory states go expand your sample size that your pulling from.

 

My Kings are tuned and excellent on and offroad just saying. @AccuTune Offroad set me up As for dude he always likes to argue with people rather than be humble. If I saw him out somewhere not sure what would happen

 

I'm growing tired of this direction of the conversation, but I will say this:

1) You come across as hypocritical when you chastise me for being skeptical of someone else's subjective experience while at the same time denying my own subjective experience.

2) Subjective experience is dependent on an individual's perception and thus is not a good way to conduct science especially a relatively rigorous/quantitative science like physics.

3) I think mountain bikes are a completely separate topic. This thread was supposed to be about anti-dive suspension design of automobiles. I kinda regret ever mentioning shocks, albeit there was a little bit of good discussion.

 

Going back to the video, one thing the author skips over is an explanation of how anti-dive geometry works. He really only explains how to measure it.

I have not done on deep dive, but some thought last night combined with some other things I've read suggest to me that anti-dive force is generated by the IFS gaining caster as it compresses. I can imagine the rotation of the steering axis outward causing a torque in the opposite direction of the torque caused by the brakes. It's similar to how a weight distributing hitch works.

This is the same IFS behavior that causes people to lose caster when lifting the truck.

Thoughts anyone?

 

The way I see it, people argue with me and I just try to explain to them why they are factually wrong. It not like I'm arguing an opinion. For the most part, these are all things people can lookup in text books and I do sometimes provide references. I guess it's the inner teacher in me. Maybe I should just let people spew misinformation without getting involved.

Mostly I'm just trying to explain things and I'm not always successful. I've learned you just have to explain things in a slightly different way to get across to someone. However, some people just don't want to learn anything new and think I'm arguing with them rather than trying to explain myself.

I think I'm humble when people explain to me why I'm wrong in a way that is convincing and that happens quite often.

Cheers!

 

https://www.tacomaworld.com/threads/brake-dive.691975/

4 years later your still trying to argue the same point. I really think we are the ones tired of this.

No your constantly trying to disprove everyone that claims that the felt effects of a change in shock can have under braking.

Yes initial geometry design plays huge role but unless we start making major changes to the platform that is null in the discussion of modification. What the base population has access to the change their suspension is spring rate and dampers.

So what you are saying is a vehicle with no shocks will feel the exact same under braking as a vehicle with shocks.

I'm not debating that under a long brake the front end will result in the same place but the rate it gets there will be effected resulting in a completely different feel and in most day to day situations it won't dip as far due to that more controlled compression.

At no point am I saying mountain bikes are the exact same but the roll the dampeners play is the same. That's where my background lies that's why I'm pulling from there. But they do have commercially available tools to measure and study suspension behavior.

Felt perception at the end of the day is all that matters here. Your the only one out here trying to disprove the masses multiple times. If someone bolts somthing on and feels an improvement that's all that matters they don't need to bring you personally a scientific study stating this decreased front end compression by 12% over a 62.25% brake input for 1.37 seconds. If your so dead set on disproven this go get scientific data for the proof you so desire to disprove everyone.

I'm not being hypocritical this is the internet where the masses are always right and you sure seem to be the minority. And it's Saturday cold as hell out why not aimlessly argue.

 

Take a deep breath and count to 10.

 

I'm good i think your the one that's upset