Off-set bushes – help needed

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  • Off-set bushes – help needed
  • Premier Icon stevied
    Subscriber

    Hi all
    I’ve just had my shock serviced at TF and whilst it was away I made some nice off-set bushes for my Intense.
    Question is: Which way do I orientate them properly in relation to the shock?
    Do I have both pointing in the same direction?
    Cheers
    Steve

    rob jackson
    Member

    both pointing towards the shock surely?

    scruff
    Member

    Holes towards the shock, the idea is to shorten the eye to eye distance.

    Premier Icon stevied
    Subscriber

    Yep, now I’ve fitted them, it makes sense.

    Happy with the (measured) results but need to get out on the trails to see what it’s done to the handling.

    Before:
    Head angle = 69 degrees
    BB height = 365mm

    After:
    Head Angle = 67 degrees
    BB height = 352mm

    scruff
    Member

    Seat angle will be slacker aswell, I dont like that for normal riding.

    toys19
    Member

    edit – I’m an idiot, again..

    doof_doof
    Member

    I mounted mine both pointing ‘down’. That way you don’t lose any travel. Just need to make sure there are no frame clashes at bottom out.

    doof_doof – Member
    I mounted mine both pointing ‘down’. That way you don’t lose any travel. Just need to make sure there are no frame clashes at bottom out.

    *Face palm*

    Pointing them down, which I assume is neither pointing to the shock or away from it, is utterly pointless. You might as well not run any. For them to slacken the bike out they need to be pointing towards the shock and if you want to steepen it, they need to point away from it. Pointing ‘down’ means the shock will have the same effective eye to eye length, so won’t change the geometry.

    doof_doof
    Member

    The whole shock is now mounted lower than it was, so the rear end is effectively cycled through it’s travel slightly. BB is lower, HA and SA are slacker, total travel not affected.

    legend
    Member

    doof doof, please tell me that your shock is mounted vertically?

    What do you mean by mounted lower? By the sounds of it, I’m wrong, so I apologise but a better explanation would help.

    doof_doof
    Member

    Yes mounted vertically (horst/4 bar configuration). The shock eyelet centreline is now below the bolt hole. unfortunately I don’t have access at the moment to the photo I took of the arrangement.

    sam42
    Member

    Oh the old offset bush argument again! Surely to slacken the head angle the holes would have to be “pointing away from the shock” effectively shortening the eye to eye length, achieving the same as compressing the shock 10ish mm? Don’t even get me started on “both pointing down”.
    EDIT- I see, vertical shock, bit surely the top offset bush should be orientated upwards? Otherwise the eye to eye remains the same, the shock just sits lower?

    sam42 – Member
    Oh the old offset bush argument again! Surely to slacken the head angle the holes would have to be “pointing away from the shock” effectively shortening the eye to eye length, achieving the same as compressing the shock 10ish mm?

    No, think about it again. The shock itself doesn’t change in length, so having the holes pointing away from the shock would length the effective eye to eye length, meaning that instead of the bike squatting down, it would get higher. To get it lower and therefore slacker, the holes need to be pointing towards the shock, so the effective eye to eye length is less.

    Premier Icon stevied
    Subscriber

    Well, by having mine both pointed ‘towards the shock’ (both holes in bushes inward) I’ve altered the head angle by 2 degrees and lowered the BB by 1/2″ 🙂

    toys19
    Member

    sam42 and doofsoof need some drawings to help I think..

    I common mistake (SPEAKING FROM EXPERIENCE) is to forget that the bushings are inside the shock eyelet.

    mattjevans
    Member

    The whole shock is now mounted lower than it was, so the rear end is effectively cycled through it’s travel slightly. BB is lower, HA and SA are slacker, total travel not affected.

    Total travel isn’t affected no matter how you mount them (unless you don’t have clearance in which case DON’T use them) – they only alter eye-to-eye ie a 190×50 shock becomes a 184×50 shock, or if mounted the other way a 196×50 shock.

    Yes mounted vertically (horst/4 bar configuration). The shock eyelet centreline is now below the bolt hole. unfortunately I don’t have access at the moment to the photo I took of the arrangement.

    Really suggest you measure your “before” and “after” BB height and head angle….. you might get a surprise

    sam42
    Member

    Sorry I was being daft! The bush sits in the shock, not the frame, I’ve twigged it now..

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