Brake dive

The term "brake dive" is used on this forum a lot. I assume people are referring to the tendency of the front of the truck to depress downward while braking. What I don't understand is:

1) Why it is a big concern?
2) Why do people use it as a metric when comparing various shock absorbers?

It's never been a concern of mine and my limited understanding of it is that it is controlled mostly by suspension geometry and spring rate; not shock absorbers.

 

Drive a Sport. Report back. Only difference is shocks.
Some people just don't like brake dive. It's more a function of shocks than geometry or components.
Better yet, remove your front shocks and then hit the brakes lol. You could park and come back in ten minutes and your truck would still be bouncing!

 

I tend to use a controlled, smooth, constant force approach to braking that leads to very little dynamic bouncing of the suspension, thus I don't see how shock absorbers come into play. If I was a guy who violently pumped his brakes while approaching a stop light, I might think otherwise.

In any case, why don't people like brake dive? Does it spill their coffee? If so, I might suggest a top for the cup. Or maybe just not over filling it.

 

Let me know how controlled and smooth when someone pulls out in front of you.
I don't know why people don't like it.
Its shocks dude. Springs are designed only to carry the load of the vehicle. Shocks are designed to control and dampen the springs.
I can explain it to you but I can't understand it for you.

 

I don't like it either. Is it a deal breaker for me? No. I will likely upgrade front struts in the future but for now I will ride stock OEM setup. No big deal.

 

Some people want the suspension to feel more responsive

some people dont care/dont notice

 

Some people, me included, don’t like having the nose of the truck dive towards the pavement if you have to stop with any force. It feels much less controlled in those situations. Under ideal circumstances, I could avoid some of the nose dive in my OR, but ideal situations were few and far between. In stop and go traffic, the up and down of the front end could get irritating. Simple as that. Not the end of the world, just a personal preference.

Also, my coffee cups have lids for this reason. Not as bad in the Sport, but I won’t chance losing my coffee. Priorities, ya know.

 

I understand why people would want a more responsive suspension, but why is brake dive used as a metric for that? I would use a metric that includes things like potholes, big dips, small cracks, whoops, curbs, speed bumps, payload effect, towing effect, jumps, wash boards, etc.

 

1) It's not.
3) Because they don't know the other ways.

Brake dive, properly known as pitch, is a byproduct of a softer suspension, which comes with many benefits. For some reason some people fret over it and I won't speculate as to why.

 

Will this still be a problem when we have flying electric cars that run on unicorn farts?

 

Springs carry all loads both static and dynamic. Your roll rates, roll gradient, pitch rate, pitch gradient, rock rates, ride frequencies, warp stiffness, and roll stiffness distribution are all defined by the suspension springs. They control the bulk of chassis and handling behavior. Shocks round out the package to control *how* you get those chassis motions and not *how much* you get.

 

its all about trade offs

Extra articulation requires a soft/flexible suspension. Body roll in all directions (forward, backward, side to side) is a side affect of a soft suspension. Off road guys are always thinking about how to maximize articulation while still being able to corner and brake safely.

Guys like me who only mob up and down logging roads don't need maximum articulation, I just want responsiveness when i tap the brakes or flick the steering wheel. Putting digressively valved Icons on my truck got rid of the body roll and the brake dive at the same time

 

So you describe a scenario where using allot of brake force to stop a vehicle would cause brake dive and thus not be a big deal as it seldomly happens.

Now imagine anything harder than an intentionally slow stop causing a dive like you expect when braking very hard.

That was my issue, every stop felt like an emergency stop. Glad I never had an emergency stop or the dive would have been extreme.

 

My OR nosedives somewhat on sudden braking and I plan to correct it with a 6112/coil upgrade up front. On the flip side a stiff suspension can lose contact while driving at high speeds on $hit paved roads (like we have here in Wisconsin).

 

This fixed my dive. My dive greatly affected by winch and bumper.

 

My OR definitely has nose dive on a sudden stop but I try to avoid that. I really like the stock suspension.

 

http://www.rapid-racer.com/suspension-tuning.php
This is an article set up for road racing but it explains the basics. One of the main problems with this conversation is that there are two different goals. One goal is road performance and the other is off-road. Those goals are usually at odds when setting up suspension.
Another problem with this conversation is the TW style of conversation. Sports don't break your spine going over pebbles and off-roads don't spin out of control under light braking

 

Articulation is suspension travel not shock absorption. The spring rates and suspension geometry will determine how far the suspension rolls. The shock absorbers determine how fast it rolls. See ShimStack's post above.

If would expect an off road suspension to have soft springs and "hard" shocks to dissipate the large about of kinetic energy created by hitting big bumps. I don't if I would describe the two together as "soft". Pickups tend to have "hard" springs so that they can heavy loads, so many off-road tuned suspension kits come with softer springs (e.g. King 2.5 coil-overs with 600 lb/in springs).

More info here:

https://accutuneoffroad.com/articles/coilover-spring-rates-for-toyota-tacoma-4runner/

I haven't actually read this article, but put it here as an example of the many articles online talking about how suspension geometry affects "brake drive".

https://www.hotrod.com/articles/antidive-suspension-tech-parameters

 

Do you think brake dive lead to your accident? Personally I've never observed any adverse effects from the very little bit that a pickup truck has.