Air bump length

I’m gearing up to install my DMZ sua kit on my 16. This is my first experience with an LT kit. I have everything I need with the exception of air bumps. I have 16” stroke fox shocks that will be mounted to a DMZ bedcage. I need to get some opinions on what length air bump to run. Seems like most people are running a 4” stroke with this kit. What are the pros/cons with a 2” vs 4” stroke?

 

Cycling the suspension and setting ride height will determine how much up travel you have and then depending on what type of shocks you go with, you might have bypass shocks that are tuneable in the last 4 inches of up travel. If you are trying to tune your shocks for maximum performance, the longer bump stops may not give you as easy of a time tuning them in that part of the travel. Most people with this setup have 2" since 16" total travel won't leave you with a whole lot of up travel without hitting your bumps with 4" bumps.

 

I have 4” bumps adjusted down to 3” travel so I had the option to go up or down later. You can get 4” set at the height you like depending on who you by them from. I had 2.5” before this on SOA.

 

I have 17.25" love to add that .25" lol of rear travel and run 4" locked off road rear bumps, I've never compressed them the whole way and have about 1.5" left which is good in case I ever take a huge hit

 

Couple of comments. If you’re setting bumps lower in anticipation of shortening a spacer to increase your bump zone, you’re also changing the bump height unless you have the baller kind that have threaded bodies and are height adjustable. While most people don’t hit stuff which causes them to go full stuff very often, if you do and the bump height was originally at the optimal point for keeping the springs going negative too much, now you’re going to be running them past the point you originally had picked as the best bump height. You’d have to cut the mounts and re-weld the cans to reset them if you shortened the spacer. I know most guys don’t bump out tons, but if you’re going to beat your truck, it’s good to dial in the bump position to keep the springs in the optimal cycling range. I guess if you set them conservatively with shorter travel and anticipated shortening the spacer so the truck bumps at the optimal height, that's at least keeping the springs safer at the expense of a bit of travel. Some guys do like 2.5" of bump travel which I think Fox might have.

And if a 4" bump is too low to the point where you're unable to bottom out ever, you don't have as much travel as you could. Unfortunately it's hard to make the perfect call over the internet without knowing a lot more about driving hard vs. cruising and other specific info.

 

https://arizonadesertshocks.com/product/air-bump-stops-2-125-inch-bump-can-style-ads-racing-shocks/

2x4” bumps that come in 2” 3” 4” stroke. The limiting spacer inside could in reality be made to any length if you asked for a special order.

 

https://classifieds.race-dezert.com/FOR_SALE:2.5”-ADS-Bump-Stops-157391

 

There is also the added adjustment of welding the cans higher then needed when dry cycled and using bump spacer rings to fine tune in real world conditions. Most manufactures have them, or you can make them yourselves.




You can adjust as evolve/upgrade your build. @Dalandser is correct, there are a lot of variable that are different for each truck and your stack of component that determine the bump stroke that best fits. Shock stroke, shock position relative to bump striker, where your bypass bump zone kicks in past the last comp tube, ect... I personally prefer to have the added adjustment for easy on the fly changes to full bump.

 

If your shocks are valved correctly a 2” stroke bump is more than enough