Brain 2.0 Fork: (hidden) 'free stroke' adjustment- Mtbr.com
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  1. #1
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    Brain 2.0 Fork: (hidden) 'free stroke' adjustment

    It was mentioned in another thread that the 'new' Brain 2.0 fork has a 'hidden' adjustment:

    SpecialWarr stated: 'The fork has a cartridge adjustment range (as mentioned above) that can tune when, where and how hard the brain kicks in. Its accessed by removing the cartridge from the fork, unlocking the locknut at the upper seal area and winding _in_ (or down) the uppermost threaded portion, tightening the locknut and throw the thing back together then test ride. The is a shop-level adjustment and shouldn't take more than ten minutes each time you adjust it.'

    So ... I pulled the damper out and can confirm that this procedure can be used to adjust the amount of free stroke in the damper before the brain engages. Factory free stroke is meant to be 25mm, I think. Some like this new feature; some hate it. The adjustment is a straightforward process for those with basic knowledge of fork maintenance. Here's the details:
    1. Remove cartridge/damper.
    Brain 2.0 Fork: (hidden) 'free stroke' adjustment-img_2580.jpg
    2. Use 20mm cone spanner and 18mm spanner to loosen the upper 18mm locknut.
    Brain 2.0 Fork: (hidden) 'free stroke' adjustment-img_2582.jpg
    3. Use 13mm spanner to wind in/out the free stroke. Re-tighten lock nut. Reassemble. You may have to re-clock the Brain after reassembly.
    Brain 2.0 Fork: (hidden) 'free stroke' adjustment-img_2583.jpg
    In (clockwise) reduces the amount of free stroke - it can be completely eliminated. Out (anti-clockwise) increases it. I don't know the maximum amount of free stroke. I didn't want to go too far (perhaps you can't). But you can definitely go from 0mm-25mm of free stroke. To measure: compress the damper shaft to the brain engagement point, mark with pen, release, measure, remove pen mark. Set the brain to a firmish setting during the process so that you can feel the platform more easily.
    Hopefully this helps people adjust if they wish. It will eliminate the 'problem' that some people have with this new feature. I actually like the free stroke.
    Mine is a 2019 Debonair Brain fork with top adjust (2019 S-Works). I think the damper is the same in the 2018 fork, but I'm not positive.

  2. #2
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    Very very useful, thanks.
    SpecialWarr also made an amazing explanation on how to do it.

    Thanks both,

    P.s - If you have by chance a video doing it, would be amazing.


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  3. #3
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    Quote Originally Posted by mmmaaaiiikkk View Post
    It was mentioned in another thread that the 'new' Brain 2.0 fork has a 'hidden' adjustment:

    SpecialWarr stated: 'The fork has a cartridge adjustment range (as mentioned above) that can tune when, where and how hard the brain kicks in. Its accessed by removing the cartridge from the fork, unlocking the locknut at the upper seal area and winding _in_ (or down) the uppermost threaded portion, tightening the locknut and throw the thing back together then test ride. The is a shop-level adjustment and shouldn't take more than ten minutes each time you adjust it.'

    So ... I pulled the damper out and can confirm that this procedure can be used to adjust the amount of free stroke in the damper before the brain engages. Factory free stroke is meant to be 25mm, I think. Some like this new feature; some hate it. The adjustment is a straightforward process for those with basic knowledge of fork maintenance. Here's the details:
    1. Remove cartridge/damper.
    Click image for larger version. 

Name:	IMG_2580.jpg 
Views:	50 
Size:	159.1 KB 
ID:	1289355
    2. Use 20mm cone spanner and 18mm spanner to loosen the upper 18mm locknut.
    Click image for larger version. 

Name:	IMG_2582.jpg 
Views:	47 
Size:	184.7 KB 
ID:	1289357
    3. Use 13mm spanner to wind in/out the free stroke. Re-tighten lock nut. Reassemble. You may have to re-clock the Brain after reassembly.
    Click image for larger version. 

Name:	IMG_2583.jpg 
Views:	43 
Size:	173.5 KB 
ID:	1289359
    In (clockwise) reduces the amount of free stroke - it can be completely eliminated. Out (anti-clockwise) increases it. I don't know the maximum amount of free stroke. I didn't want to go too far (perhaps you can't). But you can definitely go from 0mm-25mm of free stroke. To measure: compress the damper shaft to the brain engagement point, mark with pen, release, measure, remove pen mark. Set the brain to a firmish setting during the process so that you can feel the platform more easily.
    Hopefully this helps people adjust if they wish. It will eliminate the 'problem' that some people have with this new feature. I actually like the free stroke.
    Mine is a 2019 Debonair Brain fork with top adjust (2019 S-Works). I think the damper is the same in the 2018 fork, but I'm not positive.
    Hello,
    One question here, I plan to do the adjustment based on your and Specialwarrr comments.

    When I reduce the free float I can say that the brain will start working earlier and thus the “lock-out”.

    Any recommendation that you may have for doing all this process?

    Thank you,



    Sent from my iPhone using Tapatalk

  4. #4
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    The actual brain function - the movement of the inertia weight closing oil circuits - is unaffected, but, yes, reducing the ‘free float’ means that there will be less/no movement before you feel the platform.
    The adjustment process itself is very straightforward once you have the damper out.

  5. #5
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    Quote Originally Posted by mmmaaaiiikkk View Post
    The actual brain function - the movement of the inertia weight closing oil circuits - is unaffected, but, yes, reducing the ‘free float’ means that there will be less/no movement before you feel the platform.
    The adjustment process itself is very straightforward once you have the damper out.
    Thank you,


    Sent from my iPhone using Tapatalk

  6. #6
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    Quote Originally Posted by mmmaaaiiikkk View Post
    The actual brain function - the movement of the inertia weight closing oil circuits - is unaffected, but, yes, reducing the ‘free float’ means that there will be less/no movement before you feel the platform.
    The adjustment process itself is very straightforward once you have the damper out.
    Thanks for this,
    I have already done the adjustment as all the suggestions I have received.

    I have given 1 and a half turns to the mechanism. In your experience, for having 0.5cm-0.75cm, how many turns should I give?

    I have also adjusted the brain clocking, half turn.

    Any recommendation will be highly appreciated, I assume that there is some iteration on the process until the fork is fully set-up.

    Thanks,



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  7. #7
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    You’ll have to measure the stroke on your damper before you reassemble to get your own desired amount of free travel. Set the damper to full firm brain setting so you can easily feel where the platform is when making your adjustments and measuring the free stroke.

  8. #8
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    You’ll have to measure the stroke on your damper before you reassemble to get your own desired amount of free travel. Set the damper to full firm brain setting so you can easily feel where the platform is when making your adjustments and measuring the free stroke.

  9. #9
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    Quote Originally Posted by mmmaaaiiikkk View Post
    You’ll have to measure the stroke on your damper before you reassemble to get your own desired amount of free travel. Set the damper to full firm brain setting so you can easily feel where the platform is when making your adjustments and measuring the free stroke.
    Thank you, appreciate the response.

    Will do as you suggest to decrease the free-stroke. I assume that this second adjustment is as per your photos on the first post and that the Brain clocking with the damper assembled is done afterwards.

    Thanks again,


    Sent from my iPhone using Tapatalk

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