Help dialing in bump stop

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Bowhunter

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Was working on refinishing the plastic fenders and went to test out my travel and see if I could get some more

I have a 2” SL, .5” spacer, 1” BL, 1”MML, stock control arms. All done by PO. I only have about 2.5” gap between bump stops at ride height. 33x12.5x15 tires

On the front: Under hard bump (bump stop is starting to contort), I have approx 3” before I come in contact with my fender and about 1.5”-2” of shock travel left (reaching 9000s).

Questions:
1: is the misalignment of the top and bottom front bump stops a concern or normal?
2: When increasing the distance between bump stops, is it a 1:2 ratio in regards to increase bump size to wheel travel? For example: 1” less of bump = +- 2” of wheel travel? I found this math to be somewhat true when testing out a bunch of different shocks

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What is keeping your axle from more up travel? Removing the springs and cycling the suspension is the best way to see what needs attention. I have found you might need a little more bumpstop when you get full weight on diagonal tires.
 
Brianj5600 said:
What is keeping your axle from more up travel? Removing the springs and cycling the suspension is the best way to see what needs attention. I have found you might need a little more bumpstop when you get full weight on diagonal tires.
Click to expand...

Unless I’m missing something, it’s the bump stop stopping the axle from any additional up travel in those pictures
 
Take the bump stops and jounce pads out, cycle the axle to where the tire just clears the fender, then measure how much bump stop you need to stop it there. Measure the metal to metal clearance. The jounce pad will pretty much fully compress on a hard bump, so ignore it for this measurement. Check your shocks for bottoming and full extension while you're at it.
 
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The yellowish piece is to soften hard hits. They are not what limits travel. With the front suspension at rest you should have about the same amount of shock shaft as the distance between the lower bump stop and the tube above holding yellowish jounce bumper. It is pretty much impossible to get good information with the springs in.

The rear is similar, but the angle of the shock allows more travel than than the shaft is showing vs the suspension movement. To set the rear bump stops again the springs need to be removed.
 
Also, cycling one side at a time to full bump can introduce other clearance issues due to the axle/tire traveling in an arc.
 
Little lost here how cycling the suspension will help me when I believe it’s pretty clear the bump stop is what is limiting any further travel?

I figured maybe I could get a few more inches of up travel but not sure the juice is worth the squeeze because it functions really well when rock crawling as is other than it’s only about 2.5” of up travel until it hits the bump spot. And if the yellow jounce flattens under a true full bump, that would just about get my tire touching the fender so maybe good as is?

LONGJP2 said:
Also, cycling one side at a time to full bump can introduce other clearance issues due to the axle/tire traveling in an arc.
Click to expand...

Brianj5600 said:
The yellowish piece is to soften hard hits. They are not what limits travel. With the front suspension at rest you should have about the same amount of shock shaft as the distance between the lower bump stop and the tube above holding yellowish jounce bumper. It is pretty much impossible to get good information with the springs in.

The rear is similar, but the angle of the shock allows more travel than than the shaft is showing vs the suspension movement. To set the rear bump stops again the springs need to be removed.
Click to expand...
 
deadbeat son said:
In this photo, it appears that you have almost 2" more inches before you reach full bump.
Click to expand...

Thanks for the info. I was under the impression that was about as far as the yellow jounce compressed because I had my opposite rear tire up on a pile of dirt that was approx 2.5” tall which put a lot of weight onto this front corner
 
Bowhunter said:
Little lost here how cycling the suspension will help me when I believe it’s pretty clear the bump stop is what is limiting any further travel?
Click to expand...

I think the point is since the cup isn't touching yet, you haven't fully cylcle the suspension yet.
Either you have more travel or something else is preventing more travel; shocks, trackbar, control arms, etc.
 
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Bowhunter said:
Thanks for the info. I was under the impression that was about as far as the yellow jounce compressed because I had my opposite rear tire up on a pile of dirt that was approx 2.5” tall which put a lot of weight onto this front corner
Click to expand...

The jounce bumper compresses almost completely into the cup. It's difficult to compress the suspension all the way with the springs in. As has been stated in other posts in this tread, the jounce just slows down the suspension as it reaches full bump and prevents it from crashing together harshly. To test and check how to set your bump stops, you need to remove both the springs and the jounce bumper and cycle to full bump.
 
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Rickyd said:
Take the boots off the shocks so you can see how close they are to bottoming out
Click to expand...

Just for additional info, in that bump stop pic, the shocks has approx 1.5” of travel left. With my setup, these rancho 9000s at ride height have about 4.5” of the shaft exposed. Total travel on these 9000s are 8.5” so close to 50/50 split so I’m wondering if my stock control arms are what’s holding me up. I don’t think it’s the adjustable track bar but not 100% on that
 
If you don't plan on pulling your springs any time soon, try this.
Put a small plastic wire tie on the shock shafts.
Then see how high they ride up after offroading, or flexing it out in a ditch.
 
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Travel of the axle is not the same on both sides and the front wheels are often not straight ahead in real life. You need accommodate for the uneven terrain and movement of the axles by having more bump stop than you would in a straight ahead wheel orientation and parallel to the horizon axle travel. Turn the wheel stop to stop to find all the interference points and the opposite wheel in full droop.
 
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Remove the springs and fully cycle the axles.

The yellow jounces are not in any way a limit to travel.

If the bump stops are a limit to travel, then that occurs when the steel cup touches the axle pad.

Your shocks ought to be the hard limit to travel. The jounces exist to slow down the travel speed before full shock compression.

Extend the bump stops in order to make the jounces slow down the travel speed prior to full shock compression.

The shocks ought to have roughly 50/50 travel from ride height. If they do not have this, then something needs to change.

Removing the springs and fully cycling the axle will show you what needs to change.
 
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Brianj5600 said:
What is keeping your axle from more up travel? Removing the springs and cycling the suspension is the best way to see what needs attention. I have found you might need a little more bumpstop when you get full weight on diagonal tires.
Click to expand...

Brianj5600 said:
The yellowish piece is to soften hard hits. They are not what limits travel. With the front suspension at rest you should have about the same amount of shock shaft as the distance between the lower bump stop and the tube above holding yellowish jounce bumper. It is pretty much impossible to get good information with the springs in.

The rear is similar, but the angle of the shock allows more travel than than the shaft is showing vs the suspension movement. To set the rear bump stops again the springs need to be removed.
Click to expand...

deadbeat son said:
The jounce bumper compresses almost completely into the cup. It's difficult to compress the suspension all the way with the springs in. As has been stated in other posts in this tread, the jounce just slows down the suspension as it reaches full bump and prevents it from crashing together harshly. To test and check how to set your bump stops, you need to remove both the springs and the jounce bumper and cycle to full bump.
Click to expand...

LONGJP2 said:
If you don't plan on pulling your springs any time soon, try this.
Put a small plastic wire tie on the shock shafts.
Then see how high they ride up after offroading, or flexing it out in a ditch.
Click to expand...

deadbeat son said:
You’ll never know until you pull the springs out and cycle.
Click to expand...

jjvw said:
Remove the springs and fully cycle the axles.

The yellow jounces are not in any way a limit to travel.

If the bump stops are a limit to travel, then that occurs when the steel cup touches the axle pad.

Your shocks ought to be the hard limit to travel. The jounces exist to slow down the travel speed before full shock compression.

Extend the bump stops in order to make the jounces slow down the travel speed prior to full shock compression.

The shocks ought to have roughly 50/50 travel from ride height. If they do not have this, then something needs to change.

Removing the springs and fully cycling the axle will show you what needs to change.
Click to expand...

I'm detecting a pattern.
 
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jjvw said:
Remove the springs and fully cycle the axles.

The yellow jounces are not in any way a limit to travel.

If the bump stops are a limit to travel, then that occurs when the steel cup touches the axle pad.

Your shocks ought to be the hard limit to travel. The jounces exist to slow down the travel speed before full shock compression.

Extend the bump stops in order to make the jounces slow down the travel speed prior to full shock compression.

The shocks ought to have roughly 50/50 travel from ride height. If they do not have this, then something needs to change.

Removing the springs and fully cycling the axle will show you what needs to change.
Click to expand...

I agree, like you and other have said I need to pull the springs, just a little bit of a project so was hoping I could diagnose without removing

As far as the shock goes, it’s not the limiting factor in that bump stop picture, I checked and the shock had approx 1.5” left of travel.

My shocks aren’t quite 50/50 but close. I’d need to reduce lift (not a good option in my case) or get a longer shocks. The 5000s allow more a bit more travel but I prefer the 9000s over the 5000. I tried the sky jacker black maxes and fox IFP, neither were closer to 50/50 split so kind of a give and take thing.

If my shocks aren’t stopping my upward travel in that picture, what would you guess would be the next thing holding up the flex? The stock control arms?
 
Bowhunter said:
I agree, like you and other have said I need to pull the springs, just a little bit of a project so was hoping I could diagnose without removing

As far as the shock goes, it’s not the limiting factor in that bump stop picture, I checked and the shock had approx 1.5” left of travel.

My shocks aren’t quite 50/50 but close. I’d need to reduce lift (not a good option in my case) or get a longer shocks. The 5000s allow more a bit more travel but I prefer the 9000s over the 5000. I tried the sky jacker black maxes and fox IFP, neither were closer to 50/50 split so kind of a give and take thing.

If my shocks aren’t stopping my upward travel in that picture, what would you guess would be the next thing holding up the flex? The stock control arms?
Click to expand...

What was limiting the upward travel in that picture was the spring.
 
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