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  1. #1
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    scalpel rear shock pressure

    Need some help getting the proper design range for rear shock pressure on my new scalpel frame. I switched all my components over from a wrecked Rush to an extra large 2008 scalpel and am looking for a pressure range for a 185 to 195 lb rider with an rp23.

  2. #2
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    Quote Originally Posted by cannondale rider 66
    Need some help getting the proper design range for rear shock pressure on my new scalpel frame. I switched all my components over from a wrecked Rush to an extra large 2008 scalpel and am looking for a pressure range for a 185 to 195 lb rider with an rp23.
    It depends a lot on the lever ratio at the shock and I am not familiar with the 2008 Scalpel, but on a recent ride on a 2011 scalpel , I had it on good authority from a Cannondale Factory rider that a good starting point is 1:1.

    So start in the 185-195 psi range and play around with it from there.

  3. #3
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    I run about 55 PSI in mine and I weigh 155lbs, far from 1:1... IMO, just try to get the sag to about 8mm at the shock to start with, try and adjust... But the pressure could be much lower than on most bikes. You may want to set the rebound on the slow side too, the carbon stays makes the rebound quite fast so slowing it with the shock can make the ride less 'springy'...

    DAN.GEROUS.NET : MOUNTAIN BIKING : CYCLOCROSS : ROAD :

  4. #4
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    Mine's at 45-50psi on a 2009, I weigh about 140. I run "normal" suspensions at 130-140, so it's not 1:1 on the 2008. I agree about the rebound, the stays act as leaf springs themselves, so the shock only does roughly half the work of the suspension, depending on how much you weigh. The Cannondale book recommends 8-10mm of sag.

  5. #5
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    Sag is king. Adjust pressure to get the sag to 8-10mm, and that's your pressure. With your body weight, it will end up being in the 60-70lb. range.
    I can barely get my mouth around it.

  6. #6
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    My main concern was since the pivotless design acts like a spring and is already fairly stiff and the the fact that it is pivotless, was there a too low of a pressure that would over flex and stress the bike. So treat it like any other rear suspension and adjust for 10mm of sag and if you do not use all the travel reduce the air and if you routinely bottom it out increase it.

    The pressure seamed extremely low compared to the Rush and my Prophet. I will start at 70 lbs.

    thanks for the direction.

  7. #7
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    Quote Originally Posted by Dan Gerous
    I run about 55 PSI in mine and I weigh 155lbs, far from 1:1... IMO, just try to get the sag to about 8mm at the shock to start with, try and adjust... But the pressure could be much lower than on most bikes. You may want to set the rebound on the slow side too, the carbon stays makes the rebound quite fast so slowing it with the shock can make the ride less 'springy'...
    Dan, interesting to know... they have obviously made some significant changes in geometry etc.

  8. #8
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    i'd say the biggest difference between what Dan puts into his and what BBNY put into the 2011 has to do with RP23 vs RS Monarch.

    to OP - sag is the key. dont worry about exact pressure. aim for 8-10mm of sag and you'll find the sweet spot.

  9. #9
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    Quote Originally Posted by Pedalphile
    Sag is king. Adjust pressure to get the sag to 8-10mm, and that's your pressure. With your body weight, it will end up being in the 60-70lb. range.
    this

  10. #10
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    Quote Originally Posted by nathanbal
    i'd say the biggest difference between what Dan puts into his and what BBNY put into the 2011 has to do with RP23 vs RS Monarch.

    to OP - sag is the key. dont worry about exact pressure. aim for 8-10mm of sag and you'll find the sweet spot.
    Yes, I have a RP23 like Cannondale rider 66... I haven't tried a Monarch and sadly, haven't tried the 2011 Scalpel either.

    DAN.GEROUS.NET : MOUNTAIN BIKING : CYCLOCROSS : ROAD :

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    by the way, I ended up at about 80lbs and that felt good on steep rolling single track and one good down hill. Thanks for the advice.

  12. #12
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    Quote Originally Posted by Dan Gerous
    Yes, I have a RP23 like Cannondale rider 66... I haven't tried a Monarch and sadly, haven't tried the 2011 Scalpel either.
    i actually like the monarch better than the rp23. feels more under control on the downhills and with the lockout off, you can set it up in a similar way to when the rp23 had pro pedal on. you then get a proper lock out as well.

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