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  1. #1
    Old Yeller
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    '99 Rock Shox SID SL 63mm can't get full travel

    I serviced my '99 Rock Shox SID SL a while ago and noticed yesterday that I wasn't getting very much travel out of it. Its supposed to be 63mm and I'm only getting about 35mm. When I service it, I basically removed the lowers, drained all the oil and removed top caps to drain the oil out of the top. Per my instructions from Angry Asian, I added 2cc's of 5wt fork oil to the tops and 15cc's of 15wt fork oil to the lowers. Is this correct? Is there anything else to check for?

  2. #2
    rebmem rbtm
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    Quote Originally Posted by DMKiefer
    Is there anything else to check for?
    Compare the info in the following links to how you serviced the fork.

    99 Sid Maintenance Guide

    99 Sid Owners Manual

  3. #3
    Old Yeller
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    Well, the three sevice instructions I've read so far each have different fluid amounts an weights.
    Rock Shox Owners Manual says nothing is put in the top caps and 5cc's of Redrum in each lower leg.
    99 SID Maintenance Guide you linked to says nothing is put in the top caps and 5cc's of 20wt fork oil in each lower leg.
    Angryasian servic instructions say to put 2cc's of 5wt fork oil in the top caps and 10 cc's of 15wt in each lower leg. (what I originally did)

    Last night I disassembled, cleaned and put a few drops of Redrum in top caps and 5 cc's 15wt fork oil in the lowers and was able to get 45mm travel. Something I noticed when adding air to the fork was that following the recommended pressures for a 180lbs rider, (70psi in the main and 130 in the negative spring) when adding the air to the negative spring the fork compressed about 10mm effectively shortening the travel. By trying different pressures, I was able to get about 55mm travel with 60psi in the main and 85psi in the negative spring. Does this sound right? Haven't had the chance to test ride it yet but a few rides up and down the drive felt OK. Will I ever truly be able to get 63mm travel and still have air pressure in the fork?

  4. #4
    mtbr member
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    If the pressure in the negative spring is higher than the pressure in the positive spring it'll pull it down in the travel. Try putting less pressure in the negative than you have in the positive.

    Also I believe RS measured the travel with the bottom out bumpers compressed, so you won't see the full 63mm unless you totally bottom out the fork.

  5. #5
    Old Yeller
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    That makes sense. I wonder why the Rock Shox manual always suggests nearly double whats in the main spring for the negative spring. I'll give the less pressure thing a try.
    Thanks for opening my eyes and making me think, "Why didn't I think of that?"

  6. #6
    Old Yeller
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    Update: I did as mtbikerTi suggested and ended up with 95 psi in the main springs and 85psi in the negative. This gave me about 10mm sag and a lot more travel. These pressures aren't even close to the Rock Shox recommended pressures. I don't understand it but at least I go the travel I wanted. Thanks for the advice!

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