Advertise on Bikeforums.net



User Tag List

Results 1 to 20 of 20
  1. #1
    Member
    Join Date
    Oct 2010
    Posts
    31
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    How much does frame geometry matter?

    I'm not talking about a huge difference, just a slight one.

    Excuse me if I dont use the proper cycling terms... but I've decided I want a fixed gear bike. While looking at Framesets I've found a few that I like, however the one I'd rather get (because of price) has a slightly different geometry, and I dont know how much it will effect the bike as a whole.

    Here's the main two I'm looking at:

    The Eighth Inch Scrambler V3- http://www.eighthinch.com/scrambler_frame.html

    and the Mission Valencia- https://www.missionbicycle.com/frame

    Now, I THINK I would prefer the top tube to be flat or slightly sloped downward for a LITTLE bit more aggressive geometry, however the Scrambler frame seems to have an almost upward sloped top tube... it's so slight that it's hard to tell in many of the pictures. and the Valencia looks to be slightly sloped downwards... So, do you all think that it matters for the price difference?? Would I really even notice much of a change with the different geometry?

    What do you all think?? and if you have suggestions for other fixie framesets around the same price range I'm all ears, but I've read a ton of old forums on the topic of cheap fixed gear framesets, so if you have a suggestion please include some reasoning to help me decide.

    thanks alot!! I appreciate any help.

  2. #2
    GONE~
    Join Date
    Apr 2010
    Posts
    6,745
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Define "aggressive geometry".

    I hear it used a lot, but what exactly is "aggressive"?

  3. #3
    Member
    Join Date
    Oct 2010
    Posts
    31
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    downward sloped toptube as opposed to upward sloped toptube. I included that in my post.

  4. #4
    Senior Member Kayce's Avatar
    Join Date
    Aug 2010
    Location
    St Louis
    Posts
    1,846
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Aggressive refers to short stays and steep headtube and seattube. It has nothing to do with the angle of the top tube.
    Last edited by Kayce; 11-18-10 at 11:12 PM.

  5. #5
    GONE~
    Join Date
    Apr 2010
    Posts
    6,745
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Downward slopping top tube does not necessary translate to aggressive geometry; upward slopping top tube, or compact geometry, can also be "aggressive".

    You could achieve downward slopping top tube simply by buying a new fork with different length and/or add 650c wheels. The handling will be very jittery and shaky, though.

    Neither of the frames are very aggressive, if you want the downward slopping look, get the Affinity Lo Pro.

  6. #6
    Senior Member
    Join Date
    Mar 2007
    Posts
    3,980
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    It depends on all kinds of factors: riding style, aesthetics and the bike build.

  7. #7
    Member
    Join Date
    Oct 2010
    Posts
    31
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Oh, thanks. As I also said in my post I dont know what alot of cycling terms mean. (although I thought I knew that one haha)

    So, would you consider the Scrambler any less aggressive than the Valencia?

  8. #8
    Member
    Join Date
    Oct 2010
    Posts
    31
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Vixtor View Post
    Downward slopping top tube does not necessary translate to aggressive geometry; upward slopping top tube, or compact geometry, can also be "aggressive".

    You could achieve downward slopping top tube simply by buying a new fork with different length and/or add 650c wheels. The handling will be very jittery and shaky, though.

    Neither of the frames are very aggressive, if you want the downward slopping look, get the Affinity Lo Pro.
    Thanks!
    I'll check it out

  9. #9
    Senior Member Kayce's Avatar
    Join Date
    Aug 2010
    Location
    St Louis
    Posts
    1,846
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Comparing the dimension on the 55 scrambler and the 56 valencia(just those two cause Im lazy some times). The scrambler is slightly mor aggressive. Since there is a lot of confusion of what aggressive means, do you know how they handle differently(theoretically, there is such little difference between the two)?

  10. #10
    Member
    Join Date
    Oct 2010
    Posts
    31
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Do you mean aggressive handling vs. less aggressive handling?

    Correct me if I'm wrong, but doesn't an aggressive geometry give you quicker handling, more nimble a little less 'stable' ect.??

  11. #11
    GONE~
    Join Date
    Apr 2010
    Posts
    6,745
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I should point out that Scrambler's forks are 30mm in rake, which will affect how the bike will steer.

  12. #12
    Member
    Join Date
    Oct 2010
    Posts
    31
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Vixtor View Post
    I should point out that Scrambler's forks are 30mm in rake, which will affect how the bike will steer.
    How exactly would that affect it?? And I apologize if I sound clueless... but I am. apparently even more so that I thought. haha

  13. #13
    GONE~
    Join Date
    Apr 2010
    Posts
    6,745
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    If I am correct, the less the rake, the more the trail, the more stable the bike it is at speed but will not be very lively at low speed.

    David Moulton have a very cohesive article on fork rake and trail.
    http://davesbikeblog.squarespace.com...f-history.html

    More to read about how a bike handles by David Moutlon.
    http://davesbikeblog.blogspot.com/20...rrelly_30.html

  14. #14
    Member
    Join Date
    Oct 2010
    Posts
    31
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Vixtor View Post
    If I am correct, the less the rake, the more the trail, the more stable the bike it is at speed but will not be very lively at low speed.

    David Moulton have a very cohesive article on fork rake and trail.
    http://davesbikeblog.squarespace.com...f-history.html

    More to read about how a bike handles by David Moutlon.
    http://davesbikeblog.blogspot.com/20...rrelly_30.html
    Thanks! I'll read both of those. I seriously appreciate it.

  15. #15
    Chronic 1st-timer lubes17319's Avatar
    Join Date
    Jan 2006
    Location
    Lakewood, CO
    My Bikes
    ...take me places.
    Posts
    1,080
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Urban Velo also did a nice easy-to-understand geometry guide in Issue #3.

    Quote Originally Posted by Vixtor View Post
    ....David Moulton have a very cohesive article.........

    Who cares what your bike weighs, just ride it!

  16. #16
    GONE~
    Join Date
    Apr 2010
    Posts
    6,745
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I know, my English sucks...


    Very unpleasant picture to look at.

  17. #17
    Ths Hipstr Kills Masheenz cc700's Avatar
    Join Date
    Oct 2006
    Location
    seattle
    My Bikes
    tirove
    Posts
    8,551
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Cool disc "Break" picture

  18. #18
    Noob. longjohns's Avatar
    Join Date
    Apr 2010
    Location
    NYC/NJ
    Posts
    504
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    My Lo pro has fairly slack angles considering the aggressive look. I believe the headtube angle is 72-73 with a 43mm rake fork.

  19. #19
    Senior Member
    Join Date
    Oct 2004
    Location
    Toronto, Ontario
    My Bikes
    Miele Azsora
    Posts
    1,736
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    If you don't know what makes a frame "aggressive" then it isn't something you should be worried about when buying your bike. Pick something in your favorite color.
    1988 Miele Azsora

  20. #20
    Senior Member
    Join Date
    Sep 2009
    Location
    im, hungary
    Posts
    1,983
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by jtgotsjets View Post
    If you don't know what makes a frame "aggressive" then it isn't something you should be worried about when buying your bike. Pick something in your favorite color.
    +1, "aggressive" isn't always the best for the street anyways and it wont even matter if you bike around the park all day. Get the one that looks the best.

Posting Permissions

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