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PROTHANE FRONT BUMPSTOP WRITEUP

Here's a little gimmick Goatman and I worked up on my rally XJ. We wanted to use the progressive inserts for handling as well as bump control, but Goatman was concerned that they didn't provide a "hard stop" just prior to pan contact. So I sent him some 1-1/4 diameter UHMWPE solid rod (Mcmaster 5243T15) and he placed short pieces inside the insert center hole to act as a hard stop if the suspension gets that far. On this truck we probably used 6 to 8 inches of insert containing a 3" or so hard-stop within.

I'm working out procedures to where I can change both insert length and hard-stop length at the track between runs. I eventually want to use bumpstop mods to add oversteer or understeer as needed.
 
so what is the desired prothane height to uptravel ratio's for you guys that are running them? I'm running a skyjacker 6" coil that settled to 5.5; think i'll get the 6 ring 7.5" ones, 50 per side seems pricey for these things...

Cool vid
 
I think their sold in pairs, I bought the 8 ring ones about 6 months ago and I believe it was around 60 or 70 bucks shipped to my door and they came as a pair. Haven't got them in yet, still working on the dana 30 on the bench...
 
I've been pretty happy with these thus far. http://www.naxja.org/forum/showpost.php?p=245254418&postcount=12

IMG_5994-1.jpg



Video from my most recent airtime, you can see how they prevent the tires from getting into the fenders.

http://www.youtube.com/watch?v=agR2QQuZXSU

http://www.youtube.com/watch?v=wVJzCQziijA
 
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he ran the whole 400 mile trip like that and he loved em. i need to change the style of bump plate so the bolt head is recessed, and make some other minor changes. but he wants to take them in the rocks to see how they do before we really get to work on it.
 
WAM174 said:
Here's a little gimmick Goatman and I worked up on my rally XJ. We wanted to use the progressive inserts for handling as well as bump control, but Goatman was concerned that they didn't provide a "hard stop" just prior to pan contact. So I sent him some 1-1/4 diameter UHMWPE solid rod (Mcmaster 5243T15) and he placed short pieces inside the insert center hole to act as a hard stop if the suspension gets that far. On this truck we probably used 6 to 8 inches of insert containing a 3" or so hard-stop within.
Click to expand...



Here's a pick of what we did, it works so good I'm also making a set like this for our road race XJ. The clearance is tight for bottoming, so the HMWPE rod inside of the poly insert provides a definite stop. This stuff is tough, and it doesn't compress. The insert still just floats inside the spring, I just picked it up in the pic to see the rod.

standard.jpg
 
Will these style bump stops work on a rock crawling rig that doesnt do any jumping?? Im on 35"s with 6.5" of lift, 4.5" coils with a 150 spring rate, & 2" spacers, & im setting up my flex, shock travel, & bumpstops now??
 
Never gonna work except on an XJ that sees regular flight time. ;)

Mine doesn't see air time, it only sees some whoops, trails and rock crawling, but these, I think, will still be a benefit to my XJ.
 
Yeah thats why I havent romped through the desert yet, dont want to blow out my 7100's. Damn those red things sitting on my work bench are intimidating...Waiting on limit straps first or I could just use my crappy steering as a limit strap. :looney:
 
Senior_XJ said:
Will these style bump stops work on a rock crawling rig that doesnt do any jumping?? Im on 35"s with 6.5" of lift, 4.5" coils with a 150 spring rate, & 2" spacers, & im setting up my flex, shock travel, & bumpstops now??
Click to expand...

If you are *only* doing slow speed, I think a bump stop that leaves more air gap will be better because it will allow more articulation. That being said, if you ever like to drive down a Forest Service road with more skinny pedal than strictly needed for forward travel... the Prothanes are probably a good idea.
 
mine actually work awesome for both crawling and faster stuff. i dont know if i just got lucky with the sizing or what
 
Senior_XJ said:
Will these style bump stops work on a rock crawling rig that doesnt do any jumping?? Im on 35"s with 6.5" of lift, 4.5" coils with a 150 spring rate, & 2" spacers, & im setting up my flex, shock travel, & bumpstops now??
Click to expand...



You need good bump stops even if you rock crawl and do trails, and these will work well. Bump stops normally don't limit articulation unless the spring rate is too soft. If you can bottom the suspension when articulating it's going to be pretty soft for bumps and ruts on the access roads. I ran these on my XJ (in fact I guess I started this) and it was a very good rock crawler.
 
Senior_XJ said:
Will these style bump stops work on a rock crawling rig that doesnt do any jumping?? Im on 35"s with 6.5" of lift, 4.5" coils with a 150 spring rate, & 2" spacers, & im setting up my flex, shock travel, & bumpstops now??
Click to expand...

They work fine for both.
IMG_4856.jpg
 
Another vote for being great for the slow stuff and the fast stuff. I dont remember how long I've had mine but 2-3 yrs anyways. I just had to cut a rung off to accomodate my acos.

2011-03-21161129.jpg
 
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