Results 1 to 11 of 11
  1. #1
    mtbr member
    Reputation:
    Join Date
    Jan 2012
    Posts
    627

    G2 Geometry..Can Someone Explain It To Me??

    I've been looking for a fork for my new Intense build, and I keep coming across forks on eBay with G2 geometry. Can someone please explain just what the advantages, or disadvantages of this system are? The fork I'm looking at is 140mm travel.
    http://kevinboyer.zenfolio.com/

    *2015 Knolly Warden...Custom Build*
    *2014 Knolly Endorphin...Custom Build*

  2. #2
    mtbr member
    Reputation:
    Join Date
    Jan 2004
    Posts
    7,888
    Quote Originally Posted by kevinboyer View Post
    I've been looking for a fork for my new Intense build, and I keep coming across forks on eBay with G2 geometry. Can someone please explain just what the advantages, or disadvantages of this system are? The fork I'm looking at is 140mm travel.
    Gary Fisher G2 Geometry - YouTube

    Gary Fisher G2 - YouTube

  3. #3
    mtbr member
    Reputation:
    Join Date
    Mar 2012
    Posts
    180
    G2 forks have a 51 mm offset the purpose of this is to reduce the "Trail" of the fork so the bike will stear quicker. The reason they do this is two fold.
    1) A G2 Bike (Gary Fisher / Trek 29er) will typically have a longer front triangle therefore making the entire wheel base longer. They do this so you can run a shorter stem which also results in quicker handling.

    2) The G2 Gemetry uses a Slack head angle (for XC purposes) of 69.5 degrees. This paired with the overall longer wheel base makes for a stable ride. In order to make that 69.5 degrees appear to stear quicker they install the 51 mm offset fork.

    I do not know how a 51mm offset fork will work on a Non G2 Frame, but I would bet that most people either would not notice it or if they do, it would be favorable.

    My personal opininon of G2 Frames / Fork are that I like it if I ride a frame smaller than I would from another mfg. Example: I really like my small GF Rig, but have had a hard time adapting to my Medium Superfly. I believe that had I purchased a Small Superfly, I would love it. Yet when I ride a Medium Santacruz Highball it fits like a glove and rips (it's a quick handling bike).

  4. #4
    psycho cyclo addict
    Reputation: edubfromktown's Avatar
    Join Date
    Sep 2010
    Posts
    2,149
    I rode a G2 Gary Fisher Rig single speed (medium) for ~10 months (along with three other large 29er's: Turner Sultan dual suspension 120mm fork, Fuji Tahoe SL geared hard tail 90+ mm fork and more recently a Niner S.I.R. 9 single speed hard tail with rigid steel fork).

    The G2 offset supposedly gives the rider more control at low and high speeds. I did not notice a dramatic difference between the Rig and my other 29er's. There are some who run a G2 fork on other frames but I would not recommend it due to increasing the chances of odd handling behavior resulting from different frame geometry design.

  5. #5
    Warrior's Society
    Reputation: mtnbikej's Avatar
    Join Date
    Sep 2001
    Posts
    6,318
    It was a bigger difference when 29er forks had a 38mm offset. Now that it seems like everybody has gone to 46mm offset, the 51mm G2 is not as big of a deal.

    I have spent considerable time on a GF Paragon and several non-G2 frames using a G2 fork....did not hinder the non-G2 frames at all.
    I resolve to constantly assert my honest opinion on anything and everything - whether it is requested or not.
    Bucky the Cat

  6. #6
    mtbr member
    Reputation:
    Join Date
    May 2007
    Posts
    127
    I agree the offset difference is not that large anymore.
    I have run a G2 superfly and a G2 fork on non G2 bikes.
    I swapped a G2 in place of an old Reba on a Bianchi Rita, bike was notably quicker, not twitchy, I would call it an improvement (71.5 HA if I recall).
    I now run a G2 on a Richey P-29 (? 70.5HA), I have not run a different fork so I can't compare directly, but it rides nicely.
    On a side note I loved my Rita, that said the Richey is a great improvement. I was a skeptic, but steel makes a clear difference, mo better.

  7. #7
    DIYer
    Reputation: bushcat's Avatar
    Join Date
    Aug 2015
    Posts
    66

    Buying a g2 fork with 51mm offset for my chinese carbon 29er full suspension

    Quote Originally Posted by murphyd View Post
    I agree the offset difference is not that large anymore.
    I have run a G2 superfly and a G2 fork on non G2 bikes.
    I swapped a G2 in place of an old Reba on a Bianchi Rita, bike was notably quicker, not twitchy, I would call it an improvement (71.5 HA if I recall).
    I now run a G2 on a Richey P-29 (? 70.5HA), I have not run a different fork so I can't compare directly, but it rides nicely.
    On a side note I loved my Rita, that said the Richey is a great improvement. I was a skeptic, but steel makes a clear difference, mo better.
    I just bid on a g2 fork on ebay because I was amazed at how low the price was for this sid rct3. I didn't realize that it's "specifically" for g2 bikes after searching google. Reading this post doesn't make me think it matters putting this fork on my non g2 frame. Thoughts? Looking for possibly uneeded reaffirmation

  8. #8
    Trail Ninja
    Reputation: Varaxis's Avatar
    Join Date
    Mar 2010
    Posts
    4,349
    Quote Originally Posted by bushcat View Post
    I just bid on a g2 fork on ebay because I was amazed at how low the price was for this sid rct3. I didn't realize that it's "specifically" for g2 bikes after searching google. Reading this post doesn't make me think it matters putting this fork on my non g2 frame. Thoughts? Looking for possibly uneeded reaffirmation
    Hakuna matata!

  9. #9
    R.I.P. DogFriend
    Reputation: jeffj's Avatar
    Join Date
    Jan 2004
    Posts
    6,375
    Quote Originally Posted by Varaxis View Post
    Hakuna matata!
    Whoa: A two word Varaxis post :~D

    I have ridden and owned bikes with 51mm offset forks, some that were Gary Fisher/Treks that were designed as G2, and others not. I rode a Niner Air 9 alloy with a 51mm Manitou Tower Pro fork that was awesome. On paper that looks like it would be a hot twitchy mess. On the trail, I loved it.

    If you get it, I'd at least give it a shot.

  10. #10
    mtbr member
    Reputation:
    Join Date
    Jan 2012
    Posts
    9,159
    Manitou TP is 48mm offset. A Magnum Pro 29+ is 51mm offset or 48 for a 27.5+ which can take a 29 wheel.....and the Marvel Pro can be ordered in 51mm offset.

    More 29s are coming with 51mm offset from guys other than Trek nowadays like Evil and Ibis. I'd prefer it on any bike.

  11. #11
    mtbr member
    Reputation: 410sprint's Avatar
    Join Date
    Oct 2012
    Posts
    130
    Quote Originally Posted by eb1888 View Post
    More 29s are coming with 51mm offset from guys other than Trek nowadays like Evil and Ibis. I'd prefer it on any bike.
    Good point. Canfield Brothers recommends 51mm offset forks for all of their 29er frames.

Posting Permissions

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