Bike geometry

stuart_c-2
stuart_c-2 Posts: 805
edited August 2009 in MTB general
Is there any kind of basic rules or an online guide about bike geometry and it’s affect on handling.

I keep reading all the time about “slack angles” and “trail orientated” and short stem/long stem etc etc.

Would be good if there was some base reference info.
"I ride to eat"

Comments

  • nicklouse
    nicklouse Posts: 50,675
    the slacker the angles the worst the climbing ability.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Daz555
    Daz555 Posts: 3,976
    edited August 2009
    Steep angles - quick steering but twitchy at high speed.
    Slack angles - slower steering but more stable at high speed.

    XC racer will have steep angles, and DH rig will have slack angles:

    9795-17_SW_SJ_HT_natural_red_stripe_d.jpg

    Giant-Glory_bigpromo.jpg


    Stem length also impacts steering response based on rider input - short stems are quick in comparison to long. However, stem length is as much about rider position/comfort as it is about steering performance.
    You only need two tools: WD40 and Duck Tape.
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  • SUPERSUTT
    SUPERSUTT Posts: 292
    can diffrent fork lenght travel affect head and seat angle say goin from 85mm travel to 130 mm travel
    falling off doesn't hurt....its the landing that hurts


    FS Giant Trance X3 (2013)
    FS Specialized Camber 2011 (2011)=(stolen)
    HT Merlin Malt one (sold)
  • supersonic
    supersonic Posts: 82,708
    Absolutely - the static seat and head angles change roughly 1 degree per 20-25mm of increase in static fork length (ie not sat on the bike). The bottom bracket will raise slightly, and the front centre and wheelbase will increase.
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  • SUPERSUTT
    SUPERSUTT Posts: 292
    how do you check your head angle as my bike is old and no longer on the market i think its an old merlin malt 1. i was givern the frame and built it up my self as a beginer i though it is a good idea to self build so if any thing goes wrong i know how to fix it ..... dont worry ive had it checked out at a shop to make sure its safe .... the forks are marzocchi Z.5 open bath air shocks 85mm . wat was they like when they first came out and what year did they apper on the market
    falling off doesn't hurt....its the landing that hurts


    FS Giant Trance X3 (2013)
    FS Specialized Camber 2011 (2011)=(stolen)
    HT Merlin Malt one (sold)

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