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Noblehops Noblehops is offline
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Originally Posted by roger albert View Post
No, not out of patience. And glad to help even on stuff not bought from me. I call it advertising, and hope that someone eventually does. Just make it easy on me and post up the 4 numbers summarized below (both sags, both ends). Yes, you neglected the leverage ratio, and thus it should have been off instead of right on, at the end. This just illustrates how hard it is to get accurate measurements. There are a ton of places where 1 or 2mm can creep in, and add up. I see it all the time, and still do it once in a while myself. I did about 20 setups yesterday, and needed to remeasure twice. My experience happens to let me pretty easily see/feel/detect when I may have slipped up (thank god) but I sure don't bat 1000 out of the box either.
OK, I have two sets of measurements, and a very interesting observation. For starters, I redid my marks, used very thin lines, made sure they were dead vertical, and we measured everything twice to see where we were. So I feel like these are as accurate as I can get, but unfortunately I introduced a big variable - I dialed out all of the damping in the shocks on both ends, and bounced them fairly vigorously to get them to settle as best I could on the springs. I think I just made this all uninteresting to discuss by doing that, but I think I have it set right now.

First-off, remeasuring sag where we were after last night's adjustments, with all the damping out:

Rear Front

Static 11mm (was 5mm) 27mm (was 29mm)

Laden 37mm (was 34mm) 43mm (was 35mm)

Yeah, these numbers are a lot different. Then just for fun, and to make sense out of this disparity between last night's number's and tonight's, before I adjusted the springs, I dialed in about 15 clicks of rebound in the rear and measured it again. It added 7mm to the laden sag numbers.

Then I took out the rebound again so the shock was totally slack, bounced everything, readjusted both ends, measured everything twice, etc.

Rear Front

Static 11mm 27mm

Laden 32mm 35mm

So, what did I learn?

Measure everything twice, as carefully and repeatably as you can.

Wear gloves and unload the rear of the bike before you go reefing on the adjusters. Your knuckles will thank you.

You can cheat and adjust the preload in the front by grabbing onto the spring itself and twisting it in the shock body. If you're lucky, as I was, the lockrings will twist with the shock, at least in the direction of adding preload.

Unload the shock of all damping and bounce it several times to get it to settle on the correct static and laden point of the SPRING, without the input of the fluid or pressure in the damping circuits. Roger pointed this out in an older post, it bears repeating.

But wait, there's more, for reference...

Nils Menten - Tucson, Arizona, USA* 2001 R1100S "Light", gone but not forgotten.

I Do Vapor Blasting! Visit for information.
Ikon shocks for your BMW!
Old 03-20-2012, 06:32 PM
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