82 Prolink rear shock

[oldbikerdude]

I recently installed the IKON rear shock and want to change the preload.
Ride is a bit too harsh and would like to soften it up.
My rebound damper is set on 1.
My weight is 165 lbs with all riding gear.
On Youtube vids I see there are three measurements I need to take, unloaded length (bike on center stand), bike weight only length, and rider on length. (Where length is measurement from rear axle to fixed point above axle).
Apparently static sag should be around 5-10mm and rider sag from 30-40mm. These are apparently general specs, not specific.
The issue is to get at the adjusting nuts, thinking to remove the rear wheel for easy access, but this could be lots of trial and error and don't care to mess with taking wheel on and off many times.
Would be nice to be able to access the shock nuts from underneath the bike, ie: special tool, so I can make adjustments on the fly.
I had measured the distance from the locking nut to end of threads when I put the shock on at 49mm.
Anyone have experience with the IKON set up, ideally a measurement of threaded length as shown in pic. Thanks for any responses.

IMG_6095.jpg

[daves79x]

If you are set on '1' for damping, the preload is all you can adjust. If you need to take off the rear wheel, just do it once. Back off the preload a couple of threads. That's all you can do. I've installed two Ikons on Pro-Links. The damping was set for riders your weight. Both perform perfectly. Damping is slightly different between the two, one rides on '1' and the other rides on '2'. I never measured the factory set spring pre-load distance.

Dave

[oldbikerdude]

Thanks Dave for the input. ​
Since posting I had contacted IKON USA sales rep and he told me the same, back off the current preload by a couple of threads.
Monday rain is expected so I'll get the rear wheel off and make the adjustment.
Can also easily change the damper settings from 1-2, and see what difference it makes.
I take it setting 1 has the quickest rebound and 4 the slowest?

Was thinking to devise a special tool using a modified plumbers basin wrench, with the special wrench shape welded on to the swivel. This way I can have access from the bottom without taking wheel off.

[NobleHops]

Did you disassemble and grease all of the suspension linkages when you did the shock? And is the damping adjuster clicked into its setting? Eg there are no incremental settings like 1.5, the damping wheel needs to be right at the number setting, and you should feel a slight detent when selecting it. If it’s offset then the shock will definitely be very harsh because the orifice on the rod will not be aligned with the oil flow.

Dave is about your weight or a little heavier, and he’s ridden 2 or 3 Ikon equipped Prolinks I think, including mine. I have the prototype of the Ikon and I had them dial back the damping a little for the production items. I am 230# and run my shock at setting 2 and it’s excellent. I’ve never heard it described as harsh from any of the guys I have sold them to, and that makes me think something is wrong. I doubt you’re going to get much improvement from removing preload - springs are a little progressive in their action, but that’s not going to affect how the damping works, much, except in a massively over or undersprung condition. There is 1 correct preload setting for a given motorcycle with a given load on it, period, the one that results in you sitting 1/3 of the way through the total travel astride the bike with a nominal load of gear, cargo, passenger, gas. There’s a total of 10mm of preload dialed into in that spring as delivered, and the suspension leverage is about 4:1. Make your moves in very small increments at the adjusters.

[oldbikerdude]

Nils, each and every linkage was disassembled and greased.
Will def check that the damping adjuster is at set at 1 and not in between 1 and 2, but pretty sure its set at 1.
I take it that the 33% (1/3), is the rider sag, which is difference between unloaded length (measured from axle to fixed point above axle with bike on center stand) and and loaded length (same measurement with me, helmet and all my riding gear with bike on wheels). My buddy measured while I sat on the bike. Measured at 27.5 mm (399-371.5)
I did back off the preload by 2 full rotations, and it is definitely softer than before.
I didn't measure the remaining thread length of the 2 full rotations that I backed off the adjuster. It will be (49.5 - X), will measure tomorrow.
Just wanted to get a baseline, as I didn't know if the shock as sent was set to factory preload settings.