Page 1 of 2 1 2 LastLast
Results 1 to 25 of 37
  1. #1
    Unfit Norwegian
    Reputation: Dazed's Avatar
    Join Date
    Feb 2004
    Posts
    1,175

    Dirty Disco frame sizing?

    I'm getting a On-One Dirty Disco frameset, but am not sure about what size.

    I'm 5'8" (173 cm) and sort of between the manufacturers recommended sizes. I don't know whether I should go for a small (535 mm ETT) with a 100mm stem or a medium (547 mm ETT) with a 90mm stem. ...or shorter, if I'll need a shorter cockpit for cx (gravel and road. Not racing.) than for a road bike.

    I have a 31.5" (80 cm) inseam, which is shorter than average, so normally I'd choose the longer frame, but I'm concerned that 90 (or 80) mm stems and maybe a little less visible seatpost (my saddle height is 72cm from the center of the BB to the top of the saddle, and the small and medium frames have seattubes with lengths of 51,5 and 53 cm. respectively.) will look stupid and/or mess up the handling.

    I'm leaning towards medium, but would appreciate any insight.

    Thanks!

  2. #2
    mtbr member
    Reputation:
    Join Date
    Jan 2011
    Posts
    3
    80mm on a road bike (cx) will result in a very twitchy bike. So I would go for a small.

  3. #3
    mtbr member
    Reputation: mnyquist's Avatar
    Join Date
    Sep 2009
    Posts
    282
    I am 5'8" as well and would lean towards the small. I have a short inseam as well. I figure I would need an 80mm stem with the medium.

  4. #4
    Unfit Norwegian
    Reputation: Dazed's Avatar
    Join Date
    Feb 2004
    Posts
    1,175
    Thanks. I really think I'd be good with 90mm on the medium and 100mm on the small, but I guess there's not really any problems with going for a small, except maybe a shorter headtube and more aggressive riding position which I no longer need.

  5. #5
    mtbr member
    Reputation: mnyquist's Avatar
    Join Date
    Sep 2009
    Posts
    282
    Good point, you may need a few spacers on the small. Did you pull the trigger? Post some pics if you get it....sweet bike.

  6. #6
    Unfit Norwegian
    Reputation: Dazed's Avatar
    Join Date
    Feb 2004
    Posts
    1,175
    Not yet. It's still a few weeks away, I think.

    I ran a 90 mm stem on my last road bike which also had a 547mm ETT, and that wasn't twitchy. I really don't know which size to get this time.

  7. #7
    jrm
    jrm is offline
    mtbr member
    Reputation: jrm's Avatar
    Join Date
    Jan 2004
    Posts
    10,129

    Same height as you

    with about the same inseam. I'd end up riding either a 54 but most likely a 56 in order to get the 561 effective top tube. My current 55 CX frame has a 565 effective top tube.

    Buy the frame based on the top tube lenght/reach and NOT standover.
    Wreck the malls with cows on Harleys

  8. #8
    Unfit Norwegian
    Reputation: Dazed's Avatar
    Join Date
    Feb 2004
    Posts
    1,175
    Quote Originally Posted by jrm View Post
    with about the same inseam. I'd end up riding either a 54 but most likely a 56 in order to get the 561 effective top tube. My current 55 CX frame has a 565 effective top tube.

    Buy the frame based on the top tube lenght/reach and NOT standover.
    That is exactly what I'm trying to do.

    Small/535mm ETT and a 100mm stem sounds good, except the low front end, but a lot of spacers might be better than a short stem. ...But then again 90 mm might not be too short after all.

  9. #9
    mtbr member
    Reputation:
    Join Date
    Dec 2009
    Posts
    244
    I'm 5'8" also and I got the medium size. But have longer legs than you - 33". I have a stretched out position and use a 13cm stem. I use the same position I used for years on my road bikes. Like you I do gravel and dirt but don't race. Sorry this may not help. My daughter (a physical therapist and bike fitter) tells me I'm way too long in front.

    One other thing to keep in mind: the Med DD has a steep seat angle: 74 deg. If this is steeper than your old road bike it has the effect of giving the DD a longer front center than the old bike ( if you base your seat position on KOPS, that is).

    DSC04133
    Last edited by mudrock; 07-23-2013 at 10:12 AM.

  10. #10
    Unfit Norwegian
    Reputation: Dazed's Avatar
    Join Date
    Feb 2004
    Posts
    1,175
    Thanks. Seeing your bike helps a bit. Do you know your seat height? From the center of the BB to the top of the seat, along the seat tube?

    Good point about the seat angle. My last bike was 74 degrees as well.
    Last edited by Dazed; 07-09-2012 at 03:19 AM.

  11. #11
    mtbr member
    Reputation:
    Join Date
    Dec 2009
    Posts
    244
    Center of BB to top of saddle is 29.5" (75.25cm). Tip of saddle to where stem intersects bar, 22"(56cm).

  12. #12
    Unfit Norwegian
    Reputation: Dazed's Avatar
    Join Date
    Feb 2004
    Posts
    1,175
    Thanks! That's helpful.

  13. #13
    Bro Mountainbiker
    Reputation: Sheepo5669's Avatar
    Join Date
    May 2010
    Posts
    3,501
    Im coming from a bike with a 73* seat tube. Both of these bikes have the same top tube 565mm.

    How much more effective reach will the disco have beacuse of the 1* steeper ST? Are we talking mms? or like .5cms?
    Raised in a Chicken-Coop by Chickens

  14. #14
    Bro Mountainbiker
    Reputation: Sheepo5669's Avatar
    Join Date
    May 2010
    Posts
    3,501
    I did the math about the 73* ---> 74* change in seattube angle.

    In my case of having the seat in its certain position, 1* of seat tube angle changed the effective reach by about 13.5mms. This is if I kept my saddle in the exact same position in relation to the BB.

    Just FYI!

    I had to use some serious math that I never learned in Highschool. Cosine Ratios and whatnot.
    Raised in a Chicken-Coop by Chickens

  15. #15
    mtbr member
    Reputation:
    Join Date
    Dec 2009
    Posts
    244
    I'm glad someone did that. Saw your question and made a halfhearted look for an answer. I had a 73 on my own road bike and wondered the same thing. 13.5mm is a lot!

  16. #16
    mtbr member
    Reputation:
    Join Date
    Jul 2012
    Posts
    8
    I'm 5'9" and ride a 56cm road frame...think the medium will work for me?

  17. #17
    Bro Mountainbiker
    Reputation: Sheepo5669's Avatar
    Join Date
    May 2010
    Posts
    3,501
    Quote Originally Posted by mudrock View Post
    I'm glad someone did that. Saw your question and made a halfhearted look for an answer. I had a 73 on my own road bike and wondered the same thing. 13.5mm is a lot!
    No problem. I ride a 56 and have about 5 inches of seatpost hanging out.

    If my frame was larger or smaller or my seat was higher or lower that number (13.5mm) would change a bit.
    Last edited by Sheepo5669; 08-11-2012 at 06:56 AM.
    Raised in a Chicken-Coop by Chickens

  18. #18
    mtbr member
    Reputation:
    Join Date
    Dec 2009
    Posts
    244
    Quote Originally Posted by EdPharmD View Post
    I'm 5'9" and ride a 56cm road frame...think the medium will work for me?
    That seems to be the general consensus of posters on this thread. look at my set-up above. I'm a bit over 5'8" w a 33" inseam. I like a stretched out position, more than most, w a 13cm stem.

  19. #19
    Bro Mountainbiker
    Reputation: Sheepo5669's Avatar
    Join Date
    May 2010
    Posts
    3,501
    Anyone else having trouble getting their saddle back far enough? even with a 25mm setback post my saddle is slammed back.

    May upgrade to a FSA 32mm setback...

    [IMG][/IMG]

    Its actually about 5mms further back now because I was getting knee pain with my knee slightly forward of the pedal spindle
    Raised in a Chicken-Coop by Chickens

  20. #20
    mtbr member
    Reputation:
    Join Date
    Dec 2009
    Posts
    244
    I didn't have that problem. I used to use the KOPS formula on my road bike but gave that up when I went to cross. I'm definitely forward of that now with no pain. When moving your position forward, you would have to raise your saddle slightly to get the same extension. Did you try that?

  21. #21
    Bro Mountainbiker
    Reputation: Sheepo5669's Avatar
    Join Date
    May 2010
    Posts
    3,501
    Yeah I tried it about 5mm further forward than KOPS. Got knee pain but I was also dialing in my saddle height at the time, so the one or two rides where it was off could have been the culprit for the pain.

    I probably need to pony up for a real fit. Kops is probably just a good starting place...
    Raised in a Chicken-Coop by Chickens

  22. #22
    roadie
    Reputation: modbog's Avatar
    Join Date
    Jun 2011
    Posts
    665
    fwiw, and it's probably not worth much, i'm 6' and got the 54. no setback. i normally ride a 56 on road (565mm TT) i've also ridden 57 and 58, but found them more stretched out than i like. i like the compact fit. if you really want to know how it will fit you should check out a shop with a fit cycle and have them dial it in.

    but for $550 you could just buy both sizes and A/B them

  23. #23
    Bro Mountainbiker
    Reputation: Sheepo5669's Avatar
    Join Date
    May 2010
    Posts
    3,501
    Yeah, I got my saddle slammed back but Im loving the bike.

    May not be as great as mu old steel frame for gravel grinding, but for singletrack, road, and racing, this frame is awesome!
    Raised in a Chicken-Coop by Chickens

  24. #24
    mtbr member
    Reputation:
    Join Date
    Jan 2007
    Posts
    1,231
    I've been waiting on a 56, but now I'm concerned about the size. I assume the 56 is a large, 54 medium ect? I am 5'10", long arms and legs, and am comfortable on my Jamis 56 CX bike. The DD geo is pretty different- 74 ST is 1 degree slacker than the Jamis (73) and the HT length is taller by 15 MM. I'm confused as to whether this will make the ETT to long, even though they are measured within 2 MM (DD 562, Jamis 560). Any help would be appreciated.

  25. #25
    Bro Mountainbiker
    Reputation: Sheepo5669's Avatar
    Join Date
    May 2010
    Posts
    3,501
    Refer to post #14. You could ride a 54 or a 56 its up to you.
    Raised in a Chicken-Coop by Chickens

Page 1 of 2 1 2 LastLast

Posting Permissions

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