Can 15.5" compressed front shock work with 2" bumpstop, how do I calculate the bushing?

So I have a set of OME 60047L long travel front shocks on their way because I kept reading that they will work with 2" of bumpstop. Which I already have. However, tonight when I was double checking my current setup I ran into concerns about the long travel shocks.

When I calculate compressed shock length from the bottom mounting bracket to the upper bracket, I calculate that I have a space of 15.5". Sounds perfect right? However, there is a problem. When shock companies measure shocks with a stem like our front shocks, they measure to the shoulder of the stem. They don't include the bushing and hardware that sits on top of the shoulder. So now, assuming a 1" bushing and shoulder plate, I am suddenly over compressing by 1". In short, that 15.5" shock actually measures 16.5 when you measure from mounting point to mounting point.

Has anyone else noticed this? When you cycle your front suspension do you find you needed more bumpstop than calculated because of it? More to the point has anyone used an OME long travel front shock with only 2" of bumpstop and cycled it through to make sure that is enough bumpstop?

Please help me understand how to handle that rubber bushing. Is it designed to collapse? Why don't shock companies include that as part of the compressed length since it is going to take up space and add to the compressed length?

I'm really concerned about my new shocks fitting. I hate to have to send them back. But I can measure the shaft that is showing on my current shocks and it matches the distance between bumpstop and pad at ride height. Is their any reason to think the bumpstops will compress at a faster rate than the shock length? Help me understand how people get OME long travel shocks or Savvy Fox and other 15.5" shocks to work with 2" of front bumpstop.

Here is a good image of how shocks are measured.

Sorry. My post was kind of confusing. I understand the stock bumpstop compresses completely. I was referring to the bushing on the shock compressing. Let me see if I can explain better.

When I replaced my springs last summer I took some measurements with the springs removed so I would have accurate measurements when I needed new shocks. Looking at the front shock, I measured from the base of the shock where it bolts in on the bottom to the top mount where the 2 bushings will sandwich the shock mount.

You can see in the picture I found online how the stock shock mounts with a bushing on top of the shock. There is also one on the other side of the mount so the 2 bushings sandwich the mount.


So with my springs and shocks removed, when I measured my collapsed space between the bottom mount and the top mount, I measured 15 5/8". So I figured I was all set to run a 15.5" shock. However, it has now come to my attention that shock manufacturers do not measure to where the bushing will meet the mount. Instead they only measure to the top of the shock where the bushing sits on the shock. So when calculating collapsed length, I will need to add in the additional space that is taken up by that bushing that sits on top of the shock. Is that correct or am I missing something?

It seems ridiculous to me that they measure it that way because that means that a 15.5' shock will only collapse down to 15.5" plus the thickness of the bushing. For example my old shocks are spec'ed at a collapsed length of 14.5". However, if I measure to the top of the bushing that will press against the mounting surface, they actually measure 15.5". So that bushing just added an inch of collapsed length to the shock.

So how is it that I keep hearing knowledgable people say you can run a shock with a collapsed length of 15.5" with a 2" bumpstop? That just doesn't make sense to me when my current shock that is speced at 14.5" needs all of that 2" bumpstop. I'm just confused at what people are calling a 15.5" shock and how much bumpstop is needed.

What am I missing? Why isn't that rubber bushing calculated into shock length.