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Fitting a 3" stroke Avy shock

Discussion in 'The Shop' started by keeping_it_real, Nov 7, 2005.

  1. keeping_it_real

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    Bit of advice needed.

    I have a 2004 Norco A-Line, pretty much all of the parts have been upgraded by now and the bike suits me down to the ground. The shock is the Fox RC 2.75" stroke. I wasnt happy with its performance when I bought the bike. I had it revalved and re-sprung by Mojo here in the U.K. It is now better but Im looking to change it for something plusher.

    Also the standard linkage plates to me are a little thin and undersized and could be causing some flex along with the fastener/mounting hardware.

    Personally I do not see the point to 'platform valved' shocks, I would rather have a shock as compliant as possible-I can live with a little 'bob' I hardly pedal the thing anyway! The RC is running Mojo's Works valving which has a platform. It is better than stock but after trying an Avy equipped bike I realise it is still pretty un-compliant and spikes quite a bit.

    The above points have led to the possibility (as well as the UK to US exchange rate) of fitting an Avalanche DHS shock.

    Whilst I’m changing the shock I am going to get some new linkage plates machined up (F.O.C. courtesy of my work) as the frame will accept another inch of wheel travel, Iv tried with the shock off and measuring everything (taking it up to 9” from its standard 8”). I plan on keeping the BB height and head angle the same but the travel will continue another inch on from its current 8” end position due to using a 3” stroke shock as opposed to the 2.75. This increases the shock ratio from the Fox RC’s 2.87 :1 to 3:1 for the Avy with 9” wheel travel.

    I am planning to keep the length of the linkage plate the same as stock to keep the Horst link/dropout angle the same but to have the shock mounting hole ‘¼ “ further away (due to the Avy 9” eye to eye length as opposed to the RC’s 8.75”) but 3” away from the linkage main pivot point rather than the stock 2.9” position.

    Please click on the link below to Avy’s fitment chart showing the Norco Team Shore (same frame as a 2004 A-Line) to make a bit more sense.

    http://www.avalanchedownhillracing.c...004NORCOns.jpg

    My question is; how much will this alter the shock’s rising/falling rate? The linkage mounting point will be ¼” further away (towards the rear wheel) than it currently is and 0.1” further away from the linkage main pivot point. (towards the seatstay pivot point)

    Admittedly Iv not drawn it up in Autocad yet, but mentally figuring out rising/falling rates is mashing my head up.

    Any help or information would be gratefully received. Cheers.
     
    #1 -   Nov 7, 2005

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  2. Brian HCM#1

    Brian HCM#1 MMMMMMMMM BEER!!!!!!!!!!

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    Your best bet is email Craig @ Avalanche. He should be able to answer all your questions.
     
    #2 -   Nov 7, 2005