Results 1 to 6 of 6
  1. #1
    mtbr member
    Reputation: TwoNin9r's Avatar
    Join Date
    Jan 2011
    Posts
    2,610

    Cockpit tweaking, what does what?

    hey guys... i was hoping to get some help on this.

    so i'd say i'm about 99% comfortable on my bike... it's a '11 rumblefish one 19". i'm 6'3" 221# with about 33" inseam and i'm pretty sure i have my saddle height dialed in in relation to the angle of my knees, but my question is this... that 1% has really started getting to me. what do other adjustments do? here are the explanations i'm looking for:

    1) longer vs shorter stem
    2) inverted stem vs normal stem
    3) higher vs lower rise bars
    4) wider bars
    5) sweep angle on bars
    6) seatpost offset
    7) seat position on the rails (fwd vs back)
    8) seat angle
    9) anything else i didn't think of involving rider position and cockpit length/width/height

    i've searched and find quite the jubilee of information but i'm hoping to put all this data in one place not only for myself, but for others who may have the same "noobish" questions. i just want to make that one final adjustment that will put me 100% of where i need to be on the bike.

    i guess i posted this here because i'm a large dude on a (what some would consider) small bike... but EVERYONE says ride what feels right and the 19 just speaks to me... (has pretty much the same ETT as most larger bikes, i think the bike is only rated at 19" because of the short seat tube due to the curve of the TT)

  2. #2
    mtbr member
    Reputation: TowerZ29's Avatar
    Join Date
    Aug 2011
    Posts
    14
    Bottom line upfront, I'd say you've hit the nail on the head if you already have what "feels right" to you. If you've really got your bike dialed in to just 1% left till perfect, then you'll prolly never get that last bit. it will always depend upon your current requirements, trail, terrain, mood, etc...
    You can always try different settings, Ergon makes some nice adjustable grips, you can rotate your riser bar, or get an adjustable/drop seat, but at the end of the day, you risk spending too much time 'tweaking' your ride, instead of enjoying the ride.

  3. #3
    mtbr member
    Reputation: TwoNin9r's Avatar
    Join Date
    Jan 2011
    Posts
    2,610
    haha well said...

  4. #4
    mtbr member
    Reputation: GTscoob's Avatar
    Join Date
    Apr 2009
    Posts
    2,154
    Step one, set the saddle height
    Step two, set the saddle for-aft adjustment on the saddle. If you feel too far back over the pedals, run a zero-offset post to move the saddle forward more than the rails will allow.
    Step three, set the saddle angle - completely personal comfort, I like mine angled up a few degrees.
    This gets you pedalling comfortable and powerful

    Then comes the more fun and pickier handlebar/stem adjustment. Length vs rise to adjust your back angle and arm angle.

    I like this calculator for seeing the difference in length/rise of stems and how it will affect your front end cockpit:
    Stem Comparison Tool | yojimg.net

    Riser bars can be rolled backwards and forwards to allow for more or less sweep and rise - to make your wrists happy. Longer stems slow steering, short stems quicken it. Wide bars slow steering, narrow bars quicken it.

    There is a big trend towards wide bars and short stems since the wide bars allow for more control (at the expense of a less aerodynamic profile). Stems are generally shortened at the same time to compensate in the increased forward weight bias and change in steering feel with the wider bars.

    Once you've got the stem/bars comfy, position your levers so they're in a good position for seated riding and out of the saddle descending. I like brake levers inboard of the shifters to allow for one-finger braking and at a good angle to brake while descending.

  5. #5
    dru
    dru is offline
    mtbr member
    Reputation:
    Join Date
    Sep 2006
    Posts
    2,642
    Here's my take.....

    1) longer vs shorter stem
    Affects your comfort on the bike in the sense of how much you are stretched out; affects how much traction the front wheel gets; how easy it is to yank up the front; descending or ascending ease.

    2) inverted stem vs normal stem
    Stems come in a variety of angles measured perpendicular to the steerer tube called rise. Zero* and + or - 6* are common examples. Most people running a neg. rise (it's just a +ve rise flipped over) are doing so in an attempt to get their bar height lower, usually on smaller sized 29ers. Stem height affects comfort and front end traction pretty much like the explanation above for longer vs shorter.

    3) higher vs lower rise bars
    Same effect as adding or removing spacers or using stems with different angles. Affects comfort and control very much like the above.

    4) wider bars
    Allows for a more open chest, aiding breathing. Provides better leverage and control. Comfort. Some people say it affects weight transfer. Easier to hang a bar on trees.

    5) sweep angle on bars
    What works for some doesn't for others. Personal preference really.

    6) seatpost offset
    Has a big effect on effective seat tube angle. Most offset posts are around 1" compared to a zero offset. Using the same position on the saddle rails would have your butt 1" further back using an offset compared to a zero. This matters because you need to set the relationship between saddle position (your butt) and the bottom bracket. A more forward position uses slightly different muscle balance than one further back. This affects power vs endurance, and also the bike and rider's overall weight bias.

    7) seat position on the rails (fwd vs back)
    Exactly the same as above

    8) seat angle
    Comfort, but start with flat first

    9) anything else i didn't think of involving rider position and cockpit length/width/height
    Spacers, which affects the overall handle bar and stem height.

    Drew
    occasional cyclist

  6. #6
    mtbr member
    Reputation: codename47's Avatar
    Join Date
    Oct 2008
    Posts
    237
    I would say that there's a difference between riser bar + zero rise stem and lower riser/flat bar + angled stem. In second combination you can rotate the bar with less or no impact of the overall reach, but with firs - rotating forward will extend reach and will be equal to put longer stem.
    At mine I'm observing that when sweep of the bar is comfortable when descending it's not comfortable when climbing, so there must be compromise somewhere.

Similar Threads

  1. Tweaking an EBB...
    By PeT in forum Frame Building
    Replies: 15
    Last Post: 04-27-2010, 09:59 AM
  2. Tweaking my Fantom 29 Pro
    By fireflock in forum Motobecane
    Replies: 7
    Last Post: 10-28-2008, 09:12 AM
  3. Tweaking the Bumvee
    By MABman in forum Commuting
    Replies: 8
    Last Post: 10-24-2008, 05:02 PM
  4. Help with V Brakes tweaking.
    By Peramoure in forum Beginner's Corner
    Replies: 4
    Last Post: 07-12-2006, 07:16 AM
  5. tweaking/flattie help
    By Amazing Larry104 in forum Downhill - Freeride
    Replies: 6
    Last Post: 12-30-2005, 09:46 AM

Posting Permissions

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