Using bar pin eliminators to adjust travel bias (other options?)

deadbeat son

deadbeat son

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I installed OME 933/941 springs and 60046/60048 shocks on my '02 TJ X last Friday. During the process, I pulled the jounce bumpers, installed the shocks, and completely cycled the suspension. For the front axle, I was able to get to full bump with the shocks in stalled, so they didn't require any additional bump. After installing the springs, getting everything back on the ground, aligning, and taking for a test drive, I measured my ride height. I'm right at 6" from the lower spring pad to the bump jounce cup.

Given that the OME front shocks have 9.1" of travel, it seems my travel numbers are roughly 6 up / 3 down. I'm thinking of installing a 1" bumpstop extension and a BPE on the front shocks to rebias the travel to 5 ^ / 4 v. Is there a better option that anyone can recommend? Are my numbers wack and I need to start over and make sure I'm not full of crap?
 
BPE would be installed on the axle side of the shock, raising it. Giving you even less downtravel. Bring the frame side down if you can. Spacers etc..

@jjvw did it early on in his build thread.
 
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tworley said:
BPE would be installed on the axle side of the shock, raising it. Giving you even less downtravel. Bring the frame side down if you can. Spacers etc..

@jjvw did it early on in his build thread.
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I understand that the BPE would be installed on the axle side, raising the lower shock mount's resting point at ride height, but how does that reduce the down travel? If a 22" shock is resting at 19" in length, that allows for 3" down travel. Adding a 1" BPE would collapse the shock further, and it would now be resting at 18" in length, therefore increasing available down travel to 4", while reducing the up travel by 1".

Am I thinking through this wrong? How could compressing the shock further at its resting point reduce the down travel?
 
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deadbeat son said:
I understand that the BPE would be installed on the axle side, raising the lower shock mount's resting point at ride height, but how does that reduce the down travel? If a 22" shock is resting at 19" in length, that allows for 3" down travel. Adding a 1" BPE would collapse the shock further, and it would now be resting at 18" in length, therefore increasing available down travel to 4", while reducing the up travel by 1".

Am I thinking through this wrong? How could compressing the shock further at its resting point reduce the down travel?
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No--I was thinking wrong. Hadnt had my coffee 😅
 
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Why would you sacrifice up-travel, who cares what the bias is? Do you see the need for the extra inch of down? The axle is unloaded when it's down and extra wouldn't be a big deal for me at least. Loosing an inch of up travel on my Jeep would suck. If you wheel a few times and when you are disconnected notice the front off the ground I guess I could see the need but for me I'd probably notice the lack of up first and more often.
 
LieutenantJohnson said:
That will be your cheapest, easiest to get more of a balanced bias, without reduce total travel of shock. Of course you get get a different shock.
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Yeah, I just bought the shocks. Bad move on my part to buy without thinking things through more fully.


pagrey said:
Why would you sacrifice up-travel, who cares what the bias is? Do you see the need for the extra inch of down? The axle is unloaded when it's down and extra wouldn't be a big deal for me at least. Loosing an inch of up travel on my Jeep would suck. If you wheel a few times and when you are disconnected notice the front off the ground I guess I could see the need but for me I'd probably notice the lack of up first and more often.
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1. Why would you sacrifice up-travel, who cares what the bias is?

Even with a reduction of 1", I would still be well beyond the factory up travel. I measured my lift at 2.25" over stock and 6" of up travel. Therefore, the stock up was 3.75" as there was no change in bump stop length. The stock shock has 7.5" of travel, so it's reasonable to assume stock down travel was also 3.75", so a bias of 50/50.

2. Do you see the need for the extra inch of down?

Yes. In my current setup I have reduced the down travel from was available when stock by 20%. By adding BPEs and rebiasing to a 5"/4" situation I will have improved both the up and the down travel compared to stock specs. Otherwise, I've improved one while negatively impacting the other.

3. The axle is unloaded when it's down and extra wouldn't be a big deal for me at least.

Not always, what about when you hit a pot hole or similar? The axle is loaded, but also must droop to meet the change in road surface.

4. Loosing an inch of up travel on my Jeep would suck.

I'm not losing anything, I would still ahead of stock by 1.25", which is 33%.

5. If you wheel a few times and when you are disconnected notice the front off the ground I guess I could see the need but for me I'd probably notice the lack of up first and more often.

Again, what lack of up? I'll still have 33% more up than stock.
 
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You make all very good points, my only one was that you should change based on what you observe rather than what the measurements are. What your Jeep needs is entirely based on how you use it and that is something that's easy to observe. That's all, like I said all your points are good ones.
 
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pagrey said:
You make all very good points, my only one was that you should change based on what you observe rather than what the measurements are. What your Jeep needs is entirely based on how you use it and that is something that's easy to observe. That's all, like I said all your points are good ones.
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Fair enough, I'm just trying to set it up well out of the gate. I do appreciate your thoughts, and I'm not offended by someone telling me I'm doing it wrong. Yes, I can take the time and drive it for a while as is, but why not just make a quick change while I'm busy dialing everything else in? I still have to order the rear bump stops after cycling and measuring, so I can just add the inexpensive BPEs to the order. I'm really just trying to get this little stuff done before it goes into the shop for gears next Monday.

Pressurized said:
Fine tuning... Do it. I'm always jacking around with mine to get the travel fine tuned.
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I guess it's either BPEs or new shocks. :unsure:
 
deadbeat son said:
I guess it's either BPEs or new shocks. :unsure:
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If you can find a shock that gets you the extra downtravel and can still use the bump stops you have, that's the better choice. But often, the shock body gets longer when you increase extended length and that means you are changing bump stops anyway.
 
Pressurized said:
If you can find a shock that gets you the extra downtravel and can still use the bump stops you have, that's the better choice. But often, the shock body gets longer when you increase extended length and that means you are changing bump stops anyway.
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Yeah, I believe I’ll have to add bump either way. But 1” will be fine, especially with the benefits I’ll be reaping overall.
 
I put two 1/2 inch spacers to even out my travel. I have since redone my set up but ran that way for several years.

A1DF9E76-73D9-4B4A-9407-1F06AD71A856.jpeg
 
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PurpleTJAZ said:
I put two 1/2 inch spacers to even out my travel. I have since redone my set up but ran that way for several years.

View attachment 262140
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That's just about what I had for several years, along with a couple extra cup washers on the top to split the difference between the upper and lower mounts.
 
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PurpleTJAZ said:
I put two 1/2 inch spacers to even out my travel. I have since redone my set up but ran that way for several years.

View attachment 262140
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jjvw said:
That's just about what I had for several years, along with a couple extra cup washers on the top to split the difference between the upper and lower mounts.
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Thank you both. I may end up going a similar route. I don’t really need to eliminate the bar pins, I was just looking at that as a potential solution to take up some space. I’ll give the springs a few weeks to settle and will tackle then.
 
deadbeat son said:
Thank you both. I may end up going a similar route. I don’t really need to eliminate the bar pins, I was just looking at that as a potential solution to take up some space. I’ll give the springs a few weeks to settle and will tackle then.
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The bottom line is that if the bump stops limit travel before the shocks reach full compression, there will be unused shock travel. Adding spacers to either the upper or lower mount will reclaim that travel and add it to the down travel. When I did this, the shock and the bump stops very closely matched each other.

The other option (short of moving shock mounts) is to reduce the need for bump stop extension. Mine has never had more than 1.5" up front.
 
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jjvw said:
The bottom line is that if the bump stops limit travel before the shocks reach full compression, there will be unused shock travel. Adding spacers to either the upper or lower mount will reclaim that travel and add it to the down travel. When I did this, the shock and the bump stops very closely matched each other.

The other option is to reduce the need for bump stop extension. Mine has never had more than 1.5" up front.
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I clear/have factory bumps, but that results in a travel bias of 6 up 3 down. I’m looking to add bump and spacers or BPEs solely for the purpose of rebiasing.
 
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