Front bump stop upgrade (6 Viewers)

[daeojkim]

I am upgrading front bump stop with Timbren bump stop.
I come to find that there are two bumps stops on each side for each leg of the LCA.

I only had ordered 2 bump stops.

Do you think it is essential to upgrade both bump stops on each leg of LCA at the same time?

I was concerned it would mess with alignment if I change just one of two when you hit the bump.

 

[John Guedry]

How do you know if the bump stops are bad? What's the symptoms?

 

[turbo8]

My understanding is, the front stock one will ultimately limit the suspension travel. If 2 (per side) aftermarket bumps were used, they could over compress. If they over compress, you could break your shocks, shock mounts, or cvs. Won't affect alignment.

 

[bloc]

The timbrens appear to be longer than stock, which implies they would limit up travel compared to stock bumps.

So what's the point here?

 

[SDBozo]

From my understanding you remove the rear one and just replace the front. The front one is slightly lower so the rear one shouldn’t be necessary anymore with the size of the upgraded ones. I haven’t done these yet but saw someone who was doing them on Instagram and asked them about it.

 

[turbo8]

The timbrens appear to be longer than stock, which implies they would limit up travel compared to stock bumps.

So what's the point here?

They will limit travel at slow speeds, while articulating.

The point of them is to get rid of the harsh bottom outs that the stock stops allow. The Timbrens are longer, but much softer than the stock stops. They engage sooner and slow the suspension down before hitting the stock stops.

 

[TeCKis300]

Was looking into this a bit and there's some different information.

The recommendation from Durobump for the front axle is to change the rearward bump only. Leave the forward bumpstop factory.

I think it's important to recognize that these need to perform as bumpstops. Don't want them to engage too early so as to let the real suspension do the work. Even if these look small, there is relatively little travel at inner part of the a-arm. It's bad form for bumpstops to engage too early for a couple reasons: 1) they are not a tuned part of the suspension and engaging too early makes the suspension sloppy 2) they are rubber, albiet high quality. If they engage too early/too often, they run the risk of overheating and failing prematurely. Hence the recommendation they only be used at the rearward bump location, as the forward location engages earlier in the travel.

 

[TN LX570]

For what it’s worth, the instruction sheet from Timbren states to remove the rear and only install the front.

 

[nwfl4runner]

For what it’s worth, the instruction sheet from Timbren states to remove the rear and only install the front.

I think you'll find it says remove the rear and replace the rear. you gotta keep 1 of the factory ones

 

[TN LX570]

I think you'll find it says remove the rear and replace the rear. you gotta keep 1 of the factory ones

Highly likely I misread it, that makes more sense to me.

 

[MTKID]

I have Timbrens in the rear portion of the front LCA, where I thought both Durobump and Timbren requested their parts be installed, and I have DuroBumps in the front most location. DuroBump told me their product only in the front could cause it to fail and it will limit up-travel about 1/2”. This was fine with me at the time since I was just starting to run a tire size I didn’t know if it would clear everywhere. Durobump seems fine with theirs in the front most position with another aftermarket one in the rear.

(Next, I want to see how a tire fits without the shock or bumpstops in there at all, and to investigate how a longer shock would work with the top mounted higher like Monica, the Canguro race truck. Obviously, there needs to be some bumpstop but what if it could be mounted higher?)

 

[TeCKis300]

For what it’s worth, the instruction sheet from Timbren states to remove the rear and only install the front.

I was surprised by this so went looking again for their documentation. Poorly worded.

I believe the interpretation of b) is to remove and replace the rearward bumpstop only, leaving the forward OEM bumpstop in place.

 

[daeojkim]

So I got a second pair and just replaced both the front and back.
Since I have a heavy set up with steel bumper skids, winch etc having two won’t hurt.

 

[TeCKis300]

Durobumps installed. Pretty easy installation. Installed in rear position only.

Playing with AHC, these look to engage at the last 2.5" of travel. Can't say how they perform yet, as I haven't played in the dirt yet. Though not sure they'll make a huge difference as I find the AHC suspension very capable at preventing or softening G outs. Installed them only to protect my extended AHC shock now that I have 16mm worth of spacers on top in the off chance the shock engages earlier as part of the compression limiter. The 16mm spacer nets ~1.75" more droop travel, or almost 11" overall suspension travel at the front end.

 

[chriscosta416]

Anyone have issues with aftermarket bumps touching the LCA in fast low when the LX goes over 65v

 

[TeCKis300]

Anyone have issues with aftermarket bumps touching the LCA in fast low when the LX goes over 65v

Good question.

From this thread gelow, stock AHC sets up travel for 3.5" compress / 5.5" droop. AHC hunkers down 20mm/15mm F/R respectively at 62 mph, leaving about 2.8" compression travel. From my earlier measurements, Durobumps seem to engage in the last ~2.5" of travel. To your point, probably not a great things for a completely stock AHC. Would recommend a sensor lift to holistically setup the suspension better for Baja type higher speed running, where more compression travel is needed.

As I'm setup now with AHC Long Travel, I have about 5" compression to / 5" droop. The Durobumps works great across use cases with plush g-out travel.

Suspension Travel Comparison

Been meaning to do this to get some objective numbers to compare ride height versus droop travel versus compression travel. What better to do on a rainy day. Hope is that others may contribute and I'll update my table. We've known for awhile that some aftermarket suspensions increase what is...

forum.ih8mud.com

 

[chriscosta416]

Good question.

From this thread gelow, stock AHC sets up travel for 3.5" compress / 5.5" droop. AHC hunkers down 20mm/15mm F/R respectively at 62 mph, leaving about 2.8" compression travel. From my earlier measurements, Durobumps seem to engage in the last ~2.5" of travel. To your point, probably not a great things for a completely stock AHC. Would recommend a sensor lift to holistically setup the suspension better for Baja type higher speed running, where more compression travel is needed.

As I'm setup now with AHC Long Travel, I have about 5" compression to / 5" droop. The Durobumps works great across use cases with plush g-out travel.

Suspension Travel Comparison

Been meaning to do this to get some objective numbers to compare ride height versus droop travel versus compression travel. What better to do on a rainy day. Hope is that others may contribute and I'll update my table. We've known for awhile that some aftermarket suspensions increase what is...

forum.ih8mud.com

Thanks, matches my experience I had with Duros. I had to raise AHC an inch in the front to get the front duros to work in L.

The Duros for the rear are too tall even when lifted an inch. They engage too quickly and don’t allow the shock to do it’s work.

I ordered some PerryParts bumps and the fronts are taller than duros so and they engage in fast low.

However the rears are shorter than duros and work so much better.

my experience FWIW

 

[timjax]

Currently have the Timbren Active Off-Road Bumpstops front and rear. With 35's and 0 offset, I have had some front fender liner contact on some bumps and am looking for smoother engagement on whoops.

Looking to remediate this and improve ride quality by adding a second pair of front bumpstops to the Forward position, for 4 total aftermarket front bumpstops.

Any pointers on whether I should add another pair of Timbren #ABSTOF Active Off-Road Bumpstops, or add a pair from another brand such as Perry Parts or Durobumps? Or even add a pair of Timbren SES #TOFLC2 to the Forward position?

This diagram by @PerryParts is helpful for those with similar questions in this thread also:

 

[turbo8]

Currently have the Timbren Active Off-Road Bumpstops front and rear. With 35's and 0 offset, I have had some front fender liner contact on some bumps and am looking for smoother engagement on whoops.

Looking to remediate this and improve ride quality by adding a second pair of front bumpstops to the Forward position, for 4 total aftermarket front bumpstops.

Any pointers on whether I should add another pair of Timbren #ABSTOF Active Off-Road Bumpstops, or add a pair from another brand such as Perry Parts or Durobumps? Or even add a pair of Timbren SES #TOFLC2 to the Forward position?

This diagram by @PerryParts is helpful for those with similar questions in this thread also:
View attachment 3934875

You can do what I did, if you like hitting whoops. A Tundra front end helps too.
I don't feel these engage or bottom out.

 

[Jason Andrews]

Currently have the Timbren Active Off-Road Bumpstops front and rear. With 35's and 0 offset, I have had some front fender liner contact on some bumps and am looking for smoother engagement on whoops.

Looking to remediate this and improve ride quality by adding a second pair of front bumpstops to the Forward position, for 4 total aftermarket front bumpstops.

Any pointers on whether I should add another pair of Timbren #ABSTOF Active Off-Road Bumpstops, or add a pair from another brand such as Perry Parts or Durobumps? Or even add a pair of Timbren SES #TOFLC2 to the Forward position?

This diagram by @PerryParts is helpful for those with similar questions in this thread also:
View attachment 3934875

The front has a smaller length between contact points than the rear position so it will limit up travel more putting the same bumps in that position. For me it would have been too much. My LX would have been engaging them in low mode so I opted for cutting down a poly bump to fit in the front position to limit it the least while still providing more bump stop than the stock ones.

Perry Parts hadn't come out yet at that point, but it was difficult to find one with a shorter length to fit what I thought it needed to be. Have you done the fender liner mod to alleviate that rubbing? Have a pic of where it rubs?