proper bumpstopping question (hockey pucks)

**skeebs** · 12-04-2007, 02:02 PM

I haven't had the time to take it wheelin' since the new lift & tires, well - the time has come and I am heading out in 2 weeks, but need to verify the bump stops on the front end so I don't shred my front tires or destroy my front fenders.

1st here's the pic of my 3" BB:

I have to pull it apart and put the smaller puck on top - it seems to be squashing more, and I think the 2" puck would absorb the initial tension of the spring better (just as an experiment to see for myself, thats how I did the rear - 2" on bottom with 1" on top and it's looks a lot better than the front after a month of driving on it).before I forget, do I leave the stock isolator where it sets, or does that go between the BB pucks and the coil?

MAIN SUBJECT:::::
How many hockey pucks would I need to add to the bottom plate in order to properly bump stop this set up? I laid 3 in there, thinking this - 3" lift would equal 3 (1") hockey pucks to make up the difference, but that just doesn't look right. Simply because, then I end up with just a small (2 inches or so) gap between the top hockey puck and the bottom of the OE bump stop (I will get a pic of the pucks laying in there when I get home from work). I don't see this letting my suspension squash enough ....let me know your thoughts.

beryl · 12-04-2007, 02:04 PM

go flex it on something and test it out (carefully)...look and see how much is needed.

**skeebs** · 12-04-2007, 02:10 PM

Good point, will do.

A guy I work with has his Miata out in the parking lot, let me go see

Chris_ · 12-04-2007, 02:43 PM

I just posted these in another thread. 3" suspension and 1" body lift. I have 2 hockey pucks in the front, and 1 in the back. The ones in the back are mounted with 2 ton epoxy.

Front clearance.

Rear tire clearance.

**Wheelin98TJ** · 12-04-2007, 02:58 PM

1. Measure the distance between the bumpstop and the point where it contacts the axle.

2. Measure the amount of uptravel you have in your shocks before they bottom out.

3. Measure the distance between your tire and where it will contact the fender.

If #2 or #3 is less than than #1, you need to extend your bumpstops.

Take the smaller of measurement #2 or #3. This is a good starting point for how far your bumpstop should be from the point where it contacts the axle. Then subtract another 1/2" to allow for compression of the rubber bumpstop. I say good starting point because you'll have to do some fine tuning to account for turning and possible other areas where the tire may rub.

Maybe adding some hypothetical numbers to this would help clear it up.

#1 = 6"
#2 = 4"
#3 = 5"

In this scenario, you need to extend your bumpstop at least 2". Its currently allowing 6" of uptravel but your shocks only have 4".

mexican_hippie · 12-04-2007, 03:30 PM

Quote:

Originally Posted by Wheelin98TJ

1. Measure the distance between the bumpstop and the point where it contacts the axle.

2. Measure the amount of uptravel you have in your shocks before they bottom out.

3. Measure the distance between your tire and where it will contact the fender.

If #2 or #3 is less than #1, you need to extend your bumpstops.

Take the smaller of measurement #2 or #3. This is a good starting point for how far your bumpstop should be from the point where it contacts the axle. Then subtract another 1/2" to allow for compression of the rubber bumpstop. I say good starting point because you'll have to do some fine tuning to account for turning and possible other areas where the tire may rub.

Maybe adding some hypothetical numbers to this would help clear it up.

#1 = 6"
#2 = 4"
#3 = 5"

In this scenario, you need to extend your bumpstop at least 2". Its currently allowing 6" of uptravel but your shocks only have 4".

That's the best I've ever heard it explained. People also usually forget about measurement #2, only considering #1 and #3. Can this be added to the FAQ?

nolo263 · 12-04-2007, 03:42 PM

Do you put these hockey pucks in the bottom?? Does anyone have pics? I thought you had to extend the bumpstops from the top? thanks

**Wheelin98TJ** · 12-04-2007, 03:59 PM

Quote:

Originally Posted by mexican_hippie

That's the best I've ever heard it explained. People also usually forget about measurement #2, only considering #1 and #3. Can this be added to the FAQ?

Sure, I'll add a link.

Quote:

Originally Posted by nolo263

Do you put these hockey pucks in the bottom?? Does anyone have pics? I thought you had to extend the bumpstops from the top? thanks

Yes, you put them on the bottom.

It doesn't matter if you add it to the top or bottom. It actually works quite nice adding it to the bottom. Once you add too much length to the top it starts to point away from the axle. Splitting the additional length between the top and bottom helps keep the bumpstomp more in line with where it hits the axle, or in this case, where the hockey puck would be.

nolo263 · 12-04-2007, 04:36 PM

Thanks I guess I will buy some hockey pucks and try it out..

**Border Dave** · 12-04-2007, 07:04 PM

If you don't put enough bump stop in, you could overcompress your springs over time and then your jeep will sag.

benny36 · 12-04-2007, 07:16 PM

Not too hijack your thread or anything, but do you need to change your bumpstops with just a 2'' Budget Boost? I was going to order the Rubicon Express one in a couple of weeks and wasnt sure.

**skeebs** · 12-05-2007, 06:14 AM

Chris_
Thanks for the pics! Nice TJ by the way, like the front bumper - looks like a good whitetail tosser.

Wheelin98TJ
Great explanation

THANKS!

nolo263
I will post some pics this weekend for you to see.

jcssurf · 12-05-2007, 08:03 AM

I think this question should be way simpler than people are making it. Anyone with 33x12.50's on a 15x8 and no body lift? How much bumpstop do you run? Or just add whatever BL amount to the bumpstop height. All assuming tires are clearing.

I'm going to guess you need about 2" of bumpstop.

**Wheelin98TJ** · 12-05-2007, 08:15 AM

Quote:

Originally Posted by jcssurf

I think this question should be way simpler than people are making it. Anyone with 33x12.50's on a 15x8 and no body lift? How much bumpstop do you run?...

You would have to find someone with the same exact lift height, same length shocks, same height tire, and same backspacing on the wheels.

Then hope that they have their bumpstops set correctly.

Quote:

Originally Posted by jcssurf

...Or just add whatever BL amount to the bumpstop height. All assuming tires are clearing...

You do NOT add the body lift height to your extended bumpstop length.

**skeebs** · 12-05-2007, 08:32 AM

Quote:

Originally Posted by benny36

Not too hijack your thread or anything, but do you need to change your bumpstops with just a 2'' Budget Boost? I was going to order the Rubicon Express one in a couple of weeks and wasnt sure.

I would assume yes, but I am not sure. I think the 33's would rub the fenders at flex if I didn't......But let's see what other BB guys with 33's have done

anyone know about this (does it even matter?) - do I leave the stock isolator where it sets, or does that go between the BB pucks and the coil?