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PROTHANE FRONT BUMPSTOP WRITEUP

I got 3 seasons out of them, including 3 king of the hammers races, and they are just starting to chunk a little at the very top.

Maybe you have other issues, trying to use them to replace shocks or have the wrong product.. but if they only lasted you 20 miles, you certainly did something wrong.
 
After 20 miles of severe use the prothane bumps are toast. Don't waste your money if you are looking to save your suspension. Yes they do work, for a short time, but they crack down the sides and flake off. Better to save money and get hydraulic bumps.

- 1711 Jeepspeed


Mine have been on for several years now and look much the same as they did when they were new.

Pics of your setup?
 
yea something isn't right there
 
Tried them for Silver State 300. We have a new Comanche build and my partner did not want to use the Fox air bumps since he did not want to cut the bumps tops on the truck. So he made the set up identical to what every one else was doing here. About 20 miles in I was hitting the hard stops and the prothane was cracking down the sides.
Now I understand that this was an extreme circumstance but we both expected them to last the 300 miles , not the 29 that they did. My max speed was 75 mph did I come down hard on them a lot in that 29 miles, sure I did.
I could see the benefit for a normal street rig, or one that does not leave the ground frequently. That's why I said what I said. I am considering them for the rear of my Wrangler but just not for Jeepspeed. And since this is a jeepspeed area of the forum, and I have 2 jeepspeeds, I just thought I'd let others know of our experiences .

1711 Jeepspeed
 
The setup was a 3" disc attached to the factory bump tower with a button head bolt holding it in place. On the bottom a there is a 2" tall tube that acts as a hard stop (top end rounded off, bottom end welded to a suitably sized washer) bolted to a 2" bump stop pad on the bottom spring perch. The tube holds the Prothane insert centered on the bottom pad. The axle was set to where the hard stops would hit the 3" discs about centered front to back about 3/4" off to the right.
There is some sign that the right side prothane may have been flexing over enough to get caught in the open top of the tube causing chunks of poly to be chewed out of the insert from the inside, but is seems the left one just came apart top to bottom. Not sure if the damage to the right insert was before or after the spring perch got bent.(It was a kind of rough day) The left insert has damage (cracking of the polyurethane) below the level of the top of the stop tube, so it couldn't have chunked out from flexing over the opening in the tube unless it was unseated when it was compressed and started to flex sideways before it was pushed down. I kind of don't see that happening, but I suppose it's possible.

As far as Prothanes taking the place of proper shock setup,.. well, we did loose both front shocks at between 100 and 150 miles, well after the Prothanes gave out.
 
..,you certainly did something wrong.
Yes, we certainly did do something wrong, as we DNF due to suspension failure(broken shocks) which eventually caused a brake failure. Shocks failed from mis-set limit strap length (too long - my fault.)

I have a couple ideas about what I would do differently if i was setting up an all-purpose rig. Like Zoomy97ACR, I'm considering using Prothanes on the back of my Wrangler for street/trail use, but like Zoomy said, in the future for I'd opt for full air bumps for competition.

Cal: You have 3 KOH races on a set. Could you give me a link to photos of your build? Whatever I did wrong you apparently did right, and I'm interested in your setup.
 
Cal's heep is the 4643/Team Naxja/Petty Cash vehicle. I'm sure you have read at least some of that at some point?
 
Since I'm home, I was able to run out and snap a couple of pictures.

The top, torn up from contact:

IMG_20150511_173736765_zps99apzvhc.jpg


The bottom, I could have flipped them over and kept going (but bought new ones..).

IMG_20150511_173727540_zpstbphgbwr.jpg


The Delrin rod we insert in them as a hard stop. This gets replaced after every KOH or every couple of short courses. This one was getting pretty hammered, I was out of delrin so let it go longer than I should have.

IMG_20150511_173922865_zps1tzoniq7.jpg


But I won't run out again for a long time, I have 3 12' sticks sitting here..

IMG_20150511_173937669_zpsvinh1e4p.jpg
 
"very hard rubber".

I don't know that I'm sold on that point though. It will still continue to compress.. its rubber. I guess if you don't really hit them all that hard?
 
So...after reading through this whole thread I am still up in the air as to what size progressives I should go with.

5.5" RE coils, 12" Travel Fox 2.0 Resis (around 4" uptravel), 35s..
 
They are available on Amazon Prime now too
 
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