Suspension measurement question

[Treachery]

Okay. I need the help of the assmbled brethren (and sisteren). If someone could take a measurement for me, I'd really appreciate it. I would like to know the distance from the seam in the tail piece (between the soft top and the hard base) vertically down to the top of the rear axle. Not the top of the nut, or the center of the axle, the top. I don't know if it matters, but my measurement has been taken with the bike on a swingarm stand.

Here's the deal: I have installed the JRi shock, but I don't know what the build length was. It appears that it has lowered my ride height, with some unusual non-handling consequences. Since it's not simple to pull the shock and measure it, I wanted to see what others got. I'm going to futz with ride height, but I wanted to see what I could learn.

TIA!

 

[Fasteddy]

I came up with 25" +/- 1/8" bike on paddock stand...

 

[Treachery]

Hmm. That's 1 3/4" more than mine. OE shock, Eddy?

All other measurements appreciated, but that (BIG) difference prob'ly splains some things.



It also appears that I'm going to be unable to adjust the shock without pulling it back off.

 

[Fasteddy]

OOPS! I meant 24" thats why I am not a carpenter... Yes , back on the OEM shock.

 

[Treachery]

Well, still ≈3/4" longer.

 

[green_bread]

What is your weight and what spring did you get with your shock? I'm 160 and got a 600 lb spring, which my suspension guy says is way too stiff. You can tell by looking for the number on the spring. It will be the last 3 numbers of what looks like a part number.

Edit:
I also found the bike to be harder to handle after installing the rear shock with stock forks. Basically, no confidence in the front end and the bike felt super heavy turning in to the corners. It felt like it was going to wash if I tried to push much harder.

 

[Treachery]

@green_bread: I haven't identified adverse handling problems yet. I was trying to confirm my suspicion that the ride height is shorter/lower, which it appears to be. So, this isn't a moving issue, it's a sitting still issue. Sag appears to be correct.

 

[OldVet]

DO NOT REPLY TO THIS EMAIL! *************************
Dear OldVet,
Greets! I remember that you were in on the JRi shock GB. I got mine way back, but installed it a couple weeks ago. It appears that I've got …issues. Here's the deal: When I first rode the bike and got off it to put gas in, it seemed that it didn't lean much on the sidestand., etc.
@#$%! *************

Howdy,

Replying to your PM in this thread.

Sorry but I don't think I measured the stock shock other than to set the two next to each other and see if they appeared to be similar, which they were.

Like you said it is a little difficult to get an accurate measure on the bike but it appears mine is right at 290mm. My jam nut is almost center of the threads with about two more threads below it. I put it on the swingarm stand like you to get similar results.

My lean angle on the side stand is similar to what it was with the stock shock.







Hopefully this will help...

 

[Fasteddy]

FWIW, the RC8 shock I have had on and off my 390 has a spec / measured length of 290mm eye to eye and drops the back about an inch, the OEM shock is spec'ed at 300mm eye to eye and mine measured 301.5mm, you can loosen the jamb nut on bottom of OEM and adjust it a turn or two and with the QC....
My 24" measurement was done just as in above pics....

 

[Treachery]

Thanks, guys. I'm going to have to pull it off and lengthen it, unless I can get a bicycle wrench on the jam nut to loosen it. Eddy-did you notice anything about the angle of the bike on the sidestand with it squatted down that 1"?

 

[Fasteddy]

Thanks, guys. I'm going to have to pull it off and lengthen it, unless I can get a bicycle wrench on the jam nut to loosen it. Eddy-did you notice anything about the angle of the bike on the sidestand with it squatted down that 1"?

Yes, It was noticeable that it had less lean and might need a shorter side stand, There is an OEM lowering kit with a shorter stand (p/n 90212955044), or my neighbors cutoff saw....

To really "test" the RC8 shock I at least need an OEM spring, and after the proof of concept fit I now have the washers to shim the mounting bolts. I hope to find a longer WP bottom eye casting to get the correct length.

If any body has a take off OEM shock I'll pay shipping to get the spring!

 

[Formula390]

Yes, It was noticeable that it had less lean and might need a shorter side stand, There is an OEM lowering kit with a shorter stand (p/n 90212955044), or my neighbors cutoff saw....

To really "test" the RC8 shock I at least need an OEM spring, and after the proof of concept fit I now have the washers to shim the mounting bolts. I hope to find a longer WP bottom eye casting to get the correct length.

If any body has a take off OEM shock I'll pay shipping to get the spring!

Fasteddy, I'll PM you about your spring scenario as well as possible machining you'd need for your specific scenario.