OP
Amen. I'd venture to say that no two of us, excluding 100% stock rigs, have identical parts. This is why cycling the suspension is the only solution, to tell us what we need to do.
Let's talk optimal build for 31" tires
- Thread starter Irun
- Start date
I always believed that numbers could not be identical for 2 TJs. But I thought that the differences would be small. I never imagined that there could be differences so big as the above.
Anyway! Thanks everyone for the help!
I am cycling again the suspension tomorrow. Just one question. When I measure my springs. I should measure from top perch to bottom one? Leave the isolator out? How can I be as precise as possible?
Also, similar question about shocks. In order to measure ride height. Should I measure from top bolt to rear bolt? Or just the body of the shock + the shaft (without the shock mounts)?
I am cycling again the suspension tomorrow. Just one question. When I measure my springs. I should measure from top perch to bottom one? Leave the isolator out? How can I be as precise as possible?
Also, similar question about shocks. In order to measure ride height. Should I measure from top bolt to rear bolt? Or just the body of the shock + the shaft (without the shock mounts)?
my lift measurement of 4" is 16" of spring height only. The isolator stacks on top of that, so if I were to measure between perches, it would be closer to 16-3/4".
Don't forget shock length just measures to the perch for the lower washer, so it doesn't include the lower washer or the rubber bushing. Fun story, that's actually how I ended up with 4" of lift, because I measured between the shock mounts and bought RS55255 for my 3" lift and wound up with less than 4" of downtravel.
I guess an easy way to confirm the result in the shock length, would be:
1) Measure exposed shaft at ride height
2) Add the compressed length of the shock
In practice it is best to measure from the bar pin to the bottom of the stud, but then add whatever the bushing and washer will add. This measurement minus the collapsed length should be pretty close to the amount of shaft showing.
This is where measuring gets wonky. If anyone has a front shock loose, unmounted, that could measure extended length, then compare it to the advertised extended length to see where the maker is measuring at on the shock to get the advertised measurement would be helpful.
I have a 3" SL. I'm running Rancho RS55239's up front. Ride height is 18.75" measuring from the bottom bar pin to the upper shaft cup washer.
If I measured to where the upper bushing crushes to the upper perch I'd have 21.25" ride height.
And then it would be all together different again if I measured where TJim posted on the shock body. So we need a standard of measurement here.
I have a 3" SL. I'm running Rancho RS55239's up front. Ride height is 18.75" measuring from the bottom bar pin to the upper shaft cup washer.
If I measured to where the upper bushing crushes to the upper perch I'd have 21.25" ride height.
And then it would be all together different again if I measured where TJim posted on the shock body. So we need a standard of measurement here.
I think with an eye or bar pin it's measured from the bar pin or centerline of the eye, which I find completely intuitive.
with an upper stud like we have in the front is where it gets weird, because it's measured here (borrowing photo from @bobthetj03 )
Now, take a shock, like OME, that you can't measure the exposed shock shaft, and that makes it even more fun.
well, I must admit I am confused! Haha
It seems to me that the best way to calculate the Ride height of the shock would be what I mentioned above.
Just measure the exposed shock shaft (for us who don’t use ome shocks) and then add the compressed length.
Yes. This works for OME, too. You must need to do a bit more math to calculate how much shaft is exposed behind the curtain.