PROTHANE FRONT BUMPSTOP WRITEUP
- Thread starter slcpunk74
- Start date
yossarian19
NAXJA Forum User
- Location
- Grass Valley, CA
Don't listen to me : I havent' run them and was speculating. Should have said so in my post.
bcmaxx
NAXJA Forum User
- Location
- The West Kootenays,B.C. Canada
Uptravel is 6-1/2 " , air gap is 3-ish inches, re 4.5" springs
- Location
- San Diego
perfect, thanks. i have the same up travel and same springs.
TJDualsport
NAXJA Forum User
- Location
- Fullerton
heres another vid of them working in the rocks and woops.
http://www.youtube.com/watch?v=UvosKU7OM_0
http://www.youtube.com/watch?v=UvosKU7OM_0
- Location
- Columbus, In
Uh oh, got this idea running around in my noodle. Now that I have a good riding suspension, I have found that blasting down gravel roads is fun! 
Gonna have to run a puck for the next couple wheeling trips but this idea looks like it will work for me.
Gonna have to run a puck for the next couple wheeling trips but this idea looks like it will work for me.
fyrfytr1717
NAXJA Forum User
- Location
- Turlock, CA
Sweet footage of them in action TJD. Thanks for posting that up. It's amazing how much they actually compress, they feel so hard. Looks like they do a good job of self centering themselves too. Seems like they spring back a little after being compressed. You ever feel them trying to push your wheels back down (or body up) after stuffing them in the rocks?
TJDualsport
NAXJA Forum User
- Location
- Fullerton
No spring back at all. my bud whose jeep that is has only but good things to say about them.
- Location
- Columbus, In
Bringing this back, I know its been quite a while since you posted this but I am between 3 and 3.5" of lift on 32's. Not quite sure if i'd need the 5" bumps since i'm not running 36's so, do you think a 3" would cut it? Its mostly a wheeling/highway rig with a new found love of blasting down dirt roads at 50+ mph. No Jumping,
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- Location
- San Diego
i would be safe and get the larger ones, you can always cut them down to the right length
- Location
- Columbus, In
That sound logical, thought i'd just ask to be sure. I need to bumpstop properly to keep the 32's and my front fenders from meeting each other!
For now though, hockey pucks and construction adhesive will have to work.
- Location
- San Diego
there is some info somewhere about how much they compress, a percentage of their height. if you find out how much they compress then you can do some math and find out the right length you need
edit: found it
edit: found it
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- Location
- Columbus, In
jeepboy381
NAXJA Forum User
- Location
- Gresham, Or
They will compress more than that, I was running a one inch gap with 5-6 inchs of up travel on shorter prothanes and I could still bottom the shock out. I would do what goatman did and run plastic inside the prothanes to make a deffinent stopping point.
Could you be more specific? What size prothanes, and how much were they compressed when the shock bottomed?
I have these:
http://www.quadratec.com/products/16021_10X_PG.htm
(in black), and figure they'll be good with the prothanes to keep them from overcompressing. Don't have too much info on the prothanes, but from what I gather they compress about to 60%.
3.5" compresses to 2.1",
5" compresses to 3",
8" compresses to 4.8", etc.
I'm bumpstopped 3" (hockey pucks), so I plan to get the 5" prothanes to match.
jeepboy381
NAXJA Forum User
- Location
- Gresham, Or
60 % sounds more like it, I am currently running my prothanes 7.5 inchs long with a 2.5 inch gap and they only compress 1.5 inchs until I hit the solid plastic inserts I put inside the prothanes. I could cut 3/8 of an inch off the plastic inserts to use more of my shocks but you can tell in the picture that I have about 3/4 of an inch more travel I could use by looking at where the rubber bumper sits on the shock shaft. Don't use any of my measurements either because I have custom coil mounts and bumpstop plates
Previously the prothanes were 8.5 inchs long with no plastic bumpers inside them and I could bottom out the shocks hitting a big bump.
Previously the prothanes were 8.5 inchs long with no plastic bumpers inside them and I could bottom out the shocks hitting a big bump.
- Location
- Southern Maryland
So they're not bump stops but bump slows? What's the point then
Good info, it looks like this adds up. 7.5-1.5-.75= 5.25, the height where the shocks bottom. Your old setup: 8.5*.6 = 5.1, which would allow it to bottom.
For your current prothanes, 7.5*.6 = 4.5, or .75 below what you need. Throw a 1" hockey puck under them and it should be good, and softer to boot. Then you'll have a 1.5" gap and 3" of bumpstop compression.
- Location
- San Diego
you do know that 3.5" it about 40% of 9" right? meaning it compressed to about 60% its original height like srimes math shows is about right for these.
