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  1. #1
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    SB 66 Geometry Question - Help Needed

    I live in the Seattle area there is only one shop in a 100 mile radius that carries Yeti and they do not have a SB 66 for me to test ride. The SB 66 is at the top of my very short list for the next frame I'm going to buy. Although there are a couple concerns I have about the geometry which I was hoping someone could help me out and answer a couple of questions????

    1. I like my handlebars really low but it appears that the headtube length on the SB 66 is 4.9" which is really long and on paper produces a really tall stack height. In comparison to my current bike (Tracer w/ angleset) it has a 4.5" long headtube which is in line with other bikes in this catagory. Is it possible to get the handle bars as low as say a Nomad with a flush headset??

    2. I'm 5'-8" and according to Yeti's website a size medium would fit me. Although all of the bikes I have ridden in the past have been mediums with +/-23" top tube lengths. For comparison a medium Nomad has a 22.8" top tube while a large has a 23.8" top tube which is still shorter than a medium SB 66. I was hoping someone could give me the length of the down tube from the center of the fork to the center of the bottom bracket?

    Thank you everyone for your help, I hope to be on a SB 66 soon!

  2. #2
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    I think and I hope others correct me if I am wrong, Yeti will deliver your bike with a shorter stem compared to the other bikes you mentioned there.

    Most of the people on here run stems shorter than 70mm (40-50mm).

  3. #3
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    I am running into similar situation sitting between small and medium. Does anyone know the stack and reach?

  4. #4
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    GFreak: FWIW I am 5' 8.5" and was in Austin TX a couple weeks ago, I stopped in to University Cycles there because I wanted to talk about the SB's (my interest is in the 95 though). They had a large '66 on the floor so we used that as a sizing reference.

    According to both of the guys there it was clear that for the 66 I'd need a Medium, and that the stock stem would probably be good. Sitting on the large and wheeling around a little bit I feel like I could have been comfy on it in a classic "norba racer" kind of way. I was more stretched out than I would like to be for technical trail riding (my preference) and steep downs would have been a handful.

    For comparison both my current MTBs have a top tube hovering just under 24 inches. The 29er HT has a 90mm stem and 3.9" head with Reba XX 4" fork and no spacers; the 26er FS has a 100mm stem and 4.75" head with 7" Marz 66 RC2x fork with 1/2" spacer under stem. Both use the same h-bar (easton monkey-lite xc) and Chris King headset.

    I did not feel like the bars were high or that the head height was high. I do not recall if the 66 I was on had a -32 or -36 fork though and that could change things a bit. I may be biased though by the normal height of my bikes.

    If you're ordering through a shop and let them know of your needs they may very well help out with stem swap even if Yeti can't.

    A little pleasant talk and some fizzy beverages sometimes can go a long way.

  5. #5
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    It sounds to me like Yeti is using a longer top tube length to compensate for people coming from a non DH background that typically ride with a slightly longer stem - with a longer top tube typical riders, fit wise, will feel like a typical bike with a 70 mm stem and allowing them to benefit from a shorter stem.

    I still would like to know the distance from the BB to the bottom of the head tube as every frame is different. For reference, if you were to compare this measurement between the Nomad and Tracer, the Nomads length is 1" shorter than the Tracer's but the difference in TT length is .2". I believe this measurement is the best way to determine whether or not a frame will fit someone.

    Thanks for the info and the insight Bear, I really appreciate it!

  6. #6
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    It's too bad they don't publish the effective seat-tube length (BB to ETT intersect), then we could go all math-geek on them and whup out the Law of Cosines, get a little creative, and figure out your BB to top of HT length.

    Since the published info only has the physical seat tube though the best we could do would be to approximate the length of the effective seat tube and go from there. Could be significantly off, depends how accurate you need to be whether it's worth the effort though. ;^)

    Addendum: adding image attaching with ESTIMATED values for BB to top of HT.

    Addendum: based on Dogboy's measurements below, it appears my B-H estimate comes in between 1/2 and 1 inch short, just FYI.
    Attached Thumbnails Attached Thumbnails SB 66 Geometry Question - Help Needed-sb66-sizing-bb-tht.jpg  

    Last edited by bear; 03-28-2012 at 04:42 AM.

  7. #7
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    Nice work Bear! By the looks of it a small Yeti is the same size as my medium Tracer, so it will be a size small for me.

    This actually brings up another point.......It's odd to me that a size small SB 66 is roughly the same size as a medium Tracer and a large Nomad. It would be nice if frame sizes were a little more consistant across manufactures.

  8. #8
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    agreed on the sizing.

    note that the SB66 runs large compared to the SB95, as in I fit the M 66 but the L 95.

    Here's the table on the '95 in case anyone is curious for comparisons.
    Attached Thumbnails Attached Thumbnails SB 66 Geometry Question - Help Needed-sb95-sizing-bb-tht.jpg  


  9. #9
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    For question 1: The headtube on the SB66 is 44/56 zero stack and allows a zero stack lower cup with a tapered steerer. Your Tracer 49/49 headtube requires an external lower cup for a tapered steerer or a zero stack cup for a straight steerer. So for an apples to apples comparison, the total stack height with a straight steerer tube will be a bit shorter on the Tracer and with a tapered steerer the stack height will be comparable.

    For question 2: I am 5'9" and on a medium SB66. I am always a medium frame unless a bike has really, really wierd geometry. I went back and forth when deciding between a small and medium SB66 and I am 100% confident I made the right choice with the medium. Where I would normally use a 70mm stem on a bike with an average length top tube for a medium (~23-23.5"), I use a 50mm stem on the SB66 for a comparable cockpit fit but with better handling as a result of the shorter stem.

    If you would like I can get you that down tube measurement later today after work.

  10. #10
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    Quote Originally Posted by Dogboy View Post
    For question 1: The headtube on the SB66 is 44/56 zero stack and allows a zero stack lower cup with a tapered steerer. Your Tracer 49/49 headtube requires an external lower cup for a tapered steerer or a zero stack cup for a straight steerer. So for an apples to apples comparison, the total stack height with a straight steerer tube will be a bit shorter on the Tracer and with a tapered steerer the stack height will be comparable.

    For question 2: I am 5'9" and on a medium SB66. I am always a medium frame unless a bike has really, really wierd geometry. I went back and forth when deciding between a small and medium SB66 and I am 100% confident I made the right choice with the medium. Where I would normally use a 70mm stem on a bike with an average length top tube for a medium (~23-23.5"), I use a 50mm stem on the SB66 for a comparable cockpit fit but with better handling as a result of the shorter stem.

    If you would like I can get you that down tube measurement later today after work.
    I agree 100% on the sizing, I am also 5'9" and running a 50mm stem, I am very very happy with the over all feel. I can't say enough good about the bike either.
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  11. #11
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    Hey Dogboy, I would very much appreciate it if you could take that measurement for me. It sounds like there are a few others in this forum that would appreciate it as well.

    Thanks!

  12. #12
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    Quote Originally Posted by GFreak View Post
    Hey Dogboy, I would very much appreciate it if you could take that measurement for me.
    Here you go:
    Measuring from the center of the BB to the center of the head tube (at the fork crown race) it is 670mm (26.38"). Measuring from the center of the BB and in-line with the down tube to the center of the head tube (roughly half way up the HT) it is 700mm (27.56") Hope this helps.

  13. #13
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    Thank you very much! Given my preferences, I think that a size small is the right size for me.

  14. #14
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    Quote Originally Posted by GFreak View Post
    Thank you very much! Given my preferences, I think that a size small is the right size for me.
    I would probably go small if I were you and could swing it. Unless you are a little longer in the legs for your height. I am 5'11" w/shoes, little longer in the legs, typically ride large frames and on a medium and fits me pretty well with 50 mm stem (could even go shorter stem 35-45mm as I have the saddle pushed all the way forward in the max forward position). Don't think I could go much shorter in seat tube though, if at all since running a lot of exposed seatpost, about 10" when in climb position (from top of seat clamp to rails of saddle) and sub 4" in descend position.

    Go medium if primarily using bike for XC/trail riding with super short stem or go small with 50-70mm stem if doing more "AM" type of riding with speedy, jumpy, carvy, techy descents. Just my 0.02.
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