Results 1 to 13 of 13
  1. #1
    mtbr member
    Reputation: kfb66's Avatar
    Join Date
    Oct 2010
    Posts
    527

    Air Pressure: Shock & Fork?

    I'm in the process of picking out a new bike for next season and seriously thinking of switching from my 26" Stumpy h/t to a full suspension bike. On that note, a friend loaned me his S-Works Epic (2005 model i think), to take a few test rides. I'm hoping to set up the fork and shock pressures for my weight, but I don't have the manual.

    Do any of you more experienced f/s riders have a ballpark idea of what air pressure should be in fork and rear shock for a 160-170 lb rider? Both front and rear have the brain set-up but I'm guessing air pressure still makes a significant difference ...

    Thanks for any advice!

  2. #2
    mtbr member
    Reputation: GotoDengo's Avatar
    Join Date
    Aug 2010
    Posts
    893
    Set both for about 20% of sag while sitting on it. It's as good a rule of thumb as anything. Ride your bumpiest trail and if you have any leftover travel either soften up the rebound (have no idea if that applies to brain shocks or forks) or let a little more pressure out. If you bottom out, obviously pump it up a bit -- take a pump with you on your ride just in case... I doubt your buddy would appreciate a broken Brain .

    BTW, that's an awesome bike to "demo", but maybe not the best depending on what kind of riding you will be doing. It's a race-bike, and that's probably an 80mm Epic...travel will be more harsh than a "trail" bike -- say with 120mm+ travel. Something to take into consideration.

  3. #3
    mtbr member
    Reputation: kfb66's Avatar
    Join Date
    Oct 2010
    Posts
    527
    Quote Originally Posted by GotoDengo
    Set both for about 20% of sag while sitting on it. It's as good a rule of thumb as anything. Ride your bumpiest trail and if you have any leftover travel either soften up the rebound (have no idea if that applies to brain shocks or forks) or let a little more pressure out. If you bottom out, obviously pump it up a bit -- take a pump with you on your ride just in case... I doubt your buddy would appreciate a broken Brain .

    BTW, that's an awesome bike to "demo", but maybe not the best depending on what kind of riding you will be doing. It's a race-bike, and that's probably an 80mm Epic...travel will be more harsh than a "trail" bike -- say with 120mm+ travel. Something to take into consideration.
    Thanks for the quick reply, much appreciated!

    I believe it's either 80 or 90mm travel so like you said, not a real "plush" F/S. That said should still give us an idea of ride difference compared with Stumpy HT. Myself and a friend will be taking turns riding similar trails with the Epic and my Stumpy so should make for an accurate comparison.

    One of our dilemmas is deciding between the 2011 Epic (100mm) or bigger travel Stumpy FSR (130mm). We don't do any high speed xc racing, but we do compete as a 2-man team in a few 24 hr races each season. We're more of the "slow & steady" types and it has served us well with a couple 1st place finishes and one 3rd place (all on 26" hardtails)! The last race we did was in Wausau, WI and it was rough enough that the H/T's really beat the crap out of our backs, so we're thinking an upgrade to 29" F/S would be welcome at this point, and probably a faster ride over 24 hrs due to less fatigue ... even if bike weighs a bit more?

    I haven't ridden a 29er F/S yet, but I did take a 29er H/T out and was pleasantly surprised at how much faster I felt on most terrain (especially riding over obstacles) ... and maintaining momentum was much easier as well. Not quite as agile compared with my 26 H/T, but I think I could adapt once I got more saddle time on a 29er.

  4. #4
    mtbr member
    Reputation:
    Join Date
    Jul 2010
    Posts
    3,161
    The sag on my fork keeps changing as I break in the bike. Started at 25% 115 psi, then 135, then 155, and next time I will be trying 175.

    I am 162 pounds and around 175 geared up.

  5. #5
    mtbr member
    Reputation: 3034's Avatar
    Join Date
    Apr 2006
    Posts
    749
    body weight in the rear
    1/2 body weight in the front
    is a good start

  6. #6
    Never trust a fart
    Reputation: frdfandc's Avatar
    Join Date
    Sep 2007
    Posts
    4,213
    Quote Originally Posted by bing!
    The sag on my fork keeps changing as I break in the bike. Started at 25% 115 psi, then 135, then 155, and next time I will be trying 175.

    I am 162 pounds and around 175 geared up.

    Sag shouldn't change the more you ride. My 3 y/o Reba has the same sag setting now as it did when new.

    Sounds like something is messed up inside the fork if you have to continue to increase air pressure to maintain the same percentage of sag.

  7. #7
    mtbr member
    Reputation:
    Join Date
    Mar 2018
    Posts
    26
    Quote Originally Posted by frdfandc View Post
    Sag shouldn't change the more you ride. My 3 y/o Reba has the same sag setting now as it did when new.

    Sounds like something is messed up inside the fork if you have to continue to increase air pressure to maintain the same percentage of sag.
    lol he means that he is changing the pressure, not the bike

  8. #8
    Never trust a fart
    Reputation: frdfandc's Avatar
    Join Date
    Sep 2007
    Posts
    4,213
    Quote Originally Posted by cald162 View Post
    lol he means that he is changing the pressure, not the bike
    Nothing like dredging up an 8 year old thread

    Sent from my SM-G930V using Tapatalk

  9. #9
    mtbr member
    Reputation:
    Join Date
    Mar 2018
    Posts
    26
    lmao i forgot to look at the date im hella stupid

  10. #10
    Self Appointed Judge&Jury
    Reputation: DIRTJUNKIE's Avatar
    Join Date
    Oct 2000
    Posts
    33,146
    Iím under a lot of pressure and I am in shock over this 8 year old thread bump.
    Quote Originally Posted by mileslong View Post
    I passionately remove rocks and corners and other stuff I find too hard to ride.

  11. #11
    mtbr member
    Reputation: twd953's Avatar
    Join Date
    Aug 2008
    Posts
    865
    Quote Originally Posted by DIRTJUNKIE View Post
    Iím under a lot of pressure and I am in shock over this 8 year old thread bump.
    I thought the puns were only a thing on the Pinkbike comments sections.
    No dig no whine

  12. #12
    BOOM goes the dynamite!
    Reputation: noapathy's Avatar
    Join Date
    Jun 2008
    Posts
    3,991
    Quote Originally Posted by DIRTJUNKIE View Post
    Iím under a lot of pressure and I am in shock over this 8 year old thread bump.
    It's the terror of knowing what the world is about.

  13. #13
    mtbr member
    Reputation: BlueCheesehead's Avatar
    Join Date
    Jul 2010
    Posts
    1,034
    By now the dude must be up to like 100,000 psi some 8 years later...

Members who have read this thread: 60

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

THE SITE

ABOUT MTBR

VISIT US AT

© Copyright 2019 VerticalScope Inc. All rights reserved.