Sherco KYB AOSS - Search for Initial Plushness

[Brett_Summers]

About to dive into a friend's KYB AOSS off his 2019 Factory 300. I've got a set of SSS converted WP forks (CC lugs)(done by Costanzo) and they are significantly plusher in the initial part of the stroke (amazing fork). I confess I have not pulled them apart yet to see what valving is in them.

I've ridden the bike a number of times and like a few others have posted on here, they are great at speed, but slower technical riding or tight single track and they are just a bit too firm.

Anyway, looking to bring some intital plushness into these Sherco KYB's and hoping for some assistance. Rider is about 95kgs kitted up. Grade 4 rider, and mainly prefers technical to hard enduro riding. Trials back ground so knows how to get up a lot of things.

Below is the stock stack and happy to do a revalve or shuffle shims. Only issue is the 0.11 shims that KYB's run. All my spares are 0.10 (30% difference based on the cubed principle) so hoping any suggested shim swaps are based on std 0.10, 0.25 etc and not 0.11. Thanks in advance!

Rebound
20-0.11*3
13-0.11*1
18-0.11*1
16-0.11*1
14-0.11*1
12-0.11*1
11-0,25*2

Mid Speed
20-0.11*3
18-0.11*1
16-0,11*1
14-0,11*1
12-0.11*1
11-0,30*3
12-0,30*2
20-0,11*2
12-0,25*2

Compression
32-0,11*14
28-0,11*1
30-0,11*1
28-0,11*1
26-0,11*1
24-0,11*1
22-0,11*1
20-0,11*1
18-0,11*1
16-0,11*1
14-0,25*2

Low Speed 11-0,25*3

SPRING 4.2N
OIL 345ml

[shawbagga]

Where's Jakobi?!!

[JJW]

Happy to be proved wrong but my advice is to get in there and make some changes, ride, evaluate and make some more. Chances are you can make it pretty good within a few iterations.

I wouldn't get too caught up about the 0.11mm shims since they are all the same, and you will likely be removing rather than adding under the circumstances.

I've never revalved a KYB fork, but 14 x 32's seems like a logical place to pull a few shims, maybe 4 at a time and see how that goes?

Before I looked at the stacks I was thinking about increasing the mid float a bit...did you measure that? Could possibly pull a 20 from the top or even from the pivot area to let the top stack roll over easier.....both suggestions should also increase the float 0.11, which you should be able to feel by itself without a shim stack change.

Oil height is also a big one. I doubt it is over sprung unless he's a jockey.

[Jakobi]

Yerpa derpa..

Few ways to skin the cat, but basically JJW is on the money.

Approach it logically..

Considerations - make sure forks are true and not binding in any matter. Front wheel aligned, all that jazz.

What rate is the ICS spring? How much preload is on it? Has it got some free play initially, or is it under light tension when the ICS and base valve is assembled. If you've ever played with a set of Marzocchi PFP forks you'll understand the influence this plays on the initial plushness of the fork. Sometimes allowing a little cavitation at the initial stroke is beneficial.

If you want to quickly shuffle some shims.. I'd start with the base valve.

You can either pull 2 face shims off it. You could try moving the crossover up (the 28mm up to somewhere around half way between the 32s), or you could try dropping down to a 13mm clamp on the base of the stack.

Mid valve float is also an important factor that heavily impacts on the 'feel' of the fork. A tight float will always feel firm, sharp, and responsive; giving more feedback. More float tends to give more plushy mushy feeling. Both have their places depending on rider and application.

Make one change.. ride and evaluate if it was a step forwards or backwards.

[Brett_Summers]

Excellent feedback JJW and Jakobi, very much appreciated. It will likely be a few weekends before I get a chance to get into them but will start on base compression stack and report back.