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  1. #1
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    New race bike, need sizing help

    I'm going to be purchasing a rocky mountain vertex carbon frame for XC racing, im stuck between large and XL.

    Previously I have always ran with XL, I currently have a 5.5" travel bandit 29 XL with a 70mm stem, It originally had a 90mm stem that felt fine, but I tried a 70mm stem to shorten it and make it a bit more aggressive and it worked fine.

    I'm 6'3, I have had a very basic bike fit before and was told I had fairly long legs compared to torso and because of this he sat me on a large (specialized demo day) epic 29er which felt really long compared to my bandit, even though it was a size smaller (but had like a 110mm stem). I noticed the same stretched feeling when I hopped on a large vertex with a 100m stem.

    So I'm kinda leaning more toward a large, but I may need a seat post longer than 400mm... my legs are definitely in the XL category.

    Better to size up and adjust cockpit or size down and adjust cockpit? any help is appreciated thanks!
    Pivot mach 6!

  2. #2
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    Wow, I hate to do this to you, but this really becomes about preference. Some will argue on the side of the smaller bike and adjusting just to keep the shorter wheelbase. Others will tell you the peddling efficiency is paramount, and get that right, then shorten the stem. It sounds like you had experience with both types of setup, albeit on different bikes, so maybe thinking about it in those terms sheds some light to help you decide.

  3. #3
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    Quote Originally Posted by Joel RW View Post
    I'm going to be purchasing a rocky mountain vertex carbon frame for XC racing, im stuck between large and XL.

    Previously I have always ran with XL, I currently have a 5.5" travel bandit 29 XL with a 70mm stem, It originally had a 90mm stem that felt fine, but I tried a 70mm stem to shorten it and make it a bit more aggressive and it worked fine.

    I'm 6'3, I have had a very basic bike fit before and was told I had fairly long legs compared to torso and because of this he sat me on a large (specialized demo day) epic 29er which felt really long compared to my bandit, even though it was a size smaller (but had like a 110mm stem). I noticed the same stretched feeling when I hopped on a large vertex with a 100m stem.

    So I'm kinda leaning more toward a large, but I may need a seat post longer than 400mm... my legs are definitely in the XL category.

    Better to size up and adjust cockpit or size down and adjust cockpit? any help is appreciated thanks!
    I'm the same height and also carry my height in the legs. But I've got long arms as well. I've been there and back since 2003 when I switched to the big wheels, so I'll report what I have found. I'm not saying our body types are alike as everyone is certainly unique in their build, but in terms of long legs and being 6'3" - we have that similarity. I don't think there's a stem size or set up I haven't tried over the years - and it took me quite a few years to get it all dialed in correctly.

    I guess I would worry on the size L that by the time you got the seat high enough and adjusted for your legs/knees/pedal spindle relationship, it would be so far back that the bike wouldn't handle as well as the size XL would for you. It all depends on the particular frame though as L and XL can mean different things from different companies.

    I did rent a size L (they didn't have an XL available) last Thanksgiving while out visiting family in San Francisco. It had a super wide bar and super short stem. It was a nice bike (Jekyll), but it was quite a struggle to keep the front end down on climbs. Even though we are talking 26" wheels in terms of the Jekyll, the illustration of trying to fit somebody our size on a size L bike remains constant. And this moose dwarfed the bike. I'm sure the size XL would have been a better platform for me in terms of the Jekyll as a starting point for dialing in fit.

    Here I am on the Jekyll before heading out for some East Bay singletrack on Thanksgiving morning last year....

    2011-11-26 Jekyll size L

    On all my XL's (Surly, Salsa, Niner), I use 110 and 120mm stems (even a 130mm at times on my Karate Monkey). I flip the stems negative on my JET 9 and RIP 9.

    Here's my JET 9 with a set back Syntace seatpost, with my seat slammed all the way back on the rails, and my stem flipped negative 6 degrees.

    JET profile 2012

    Here's my XL Dos Niner with a layback Thomson post, seat all the way back on the rails, 120mm 0 degree stem.

    P1010006

    Do you have any profile photographs of you on previous bikes to show your preferred position and fit on a bike?

    Just as an example, here I am on a few bikes where even though they are size XL, I still look and feel like a moose on them...

    Size XL Tallboy (demo rental, seat slammed all the way back on rails of a layback post, stem flipped negative, 0 spacers)

    2012-07-07 11.23.08

    Size XL Dos Niner (120mm stem 0 degree, seatback Thomson post, seat slammed all the way back on the rails)....

    Wheelhouse Drops

    JET 9 (as pictured above)...

    BuckHill2

    And a picture that is a bit more in profile...

    Shredding the Maskenthine XC Race

    Others?

    Here are a couple of shorter guys than us, but they are 6'2" pro XC riders and how they worked around the size L or XL choice.

    Check out 6'2" Jaroslav Kulhavy's Epic (he uses a 120mm stem flipped negative 21 degrees). He rides the size L Epic.

    Or 6'2" Todd Wells (he rides the size XL Epic). He uses a 105mm stem flipped negative 6 degrees.

    Kulhavy's long legs has him rearward on the size L, so the compensation for balance and getting more weight up on the front end resulted in a negative 21 degree, 120mm long stem.

    I'm sure you could make either size L or size XL work for you. I just feel like I am stretching the limits of a size XL as it is with seats way back, long stems and still looking like a moose on them. I'm not sure how I would make a size L work. So in my particular case, I always lean to the XL size for bike choice.

    All I can suggest to you is to sit on a bunch of them, test ride, ask if they can swap out some stems and adjust the saddle position for you so you can figure it all out for yourself. I wouldn't rely on a salesman (or my opinion either).

    All the best in getting it figured out.

    BB

  4. #4
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    Thanks that is some really awesome feedback! I had a look at those two specialized riders and compared their bikes to the geometry of the rocky(which is the slightest bit shorter) it's a difficult decision because I can only get size L demo bikes, but I will be taking one out soon anyway.

    Thanks for the time put into your reply!
    Pivot mach 6!

  5. #5
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    As you can see im pretty lanky.. This was during a solo 8 hour
    Attached Thumbnails Attached Thumbnails New race bike, need sizing help-193494_10151084638367834_1372015875_o.jpg  

    New race bike, need sizing help-218394_10151084638707834_469533884_o.jpg  

    New race bike, need sizing help-620455_10151084641812834_966542146_o.jpg  

    New race bike, need sizing help-334087_10151084640972834_724626681_o.jpg  

    New race bike, need sizing help-599404_10151084643952834_464803194_n.jpg  

    Pivot mach 6!

  6. #6
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    Quote Originally Posted by Joel RW View Post
    Thanks that is some really awesome feedback! I had a look at those two specialized riders and compared their bikes to the geometry of the rocky(which is the slightest bit shorter) it's a difficult decision because I can only get size L demo bikes, but I will be taking one out soon anyway.

    Thanks for the time put into your reply!
    It's pretty typical situation not to be able to get a demo bike in the size one would like to try. It's better these days than it was 5 - 10 years ago for sure, but still makes it difficult when making choices.

    Your photos sure point to a really good fit on the size XL. Also shows you like a nice and low aggressive position on the bike. Talk to me when you hit 50 about that....

    The XL Vertex, when I compare it to my XL Niner, has 17mm shorter chainstays, the headtube length is 15mm shorter, a shorter TT which makes it all a bit more "compact" of an XL than Niner's geometry for example. The size L Vertex only has a 115mm HT length - and the XL has a 130mm length. So that will factor into how you dial in the front end plumbing. No doubt the size L will require a lot of exposed seatpost with the seattube length on that size being only 470mm. Compared to the Air 9 Carbon, that's 1/2" shorter than their size L (and the XL Vertex is 1" shorter than Niner's XL carbon frame).

    I think your test ride on the Vertex L will be your best proving ground to answer all your questions. Take it up to race speed and see how the bike handles in that size for you compared to your current XL FS. Just looking at the geometry chart of the XL Vertex - it is smaller than all of my XL's except the Karate Monkey XL (my "smallest" XL). In fact, the Vertex XL is very similar on paper to the Karate Monkey XL when it comes to chainstay, top tube, head tube length, seat angle. The Vertex is slacker on the head tube angle than a KM, but it does give me a bit of idea of at least what a size XL Vertex would be like. As a tweener, and based on comparing those numbers, I would reach for the XL Vertex for myself without any question.

    Most guys who are 6'3" - at least according to the typical sizing chart guide for body height - are right in the "tweener" spot where they list 6'3" as the tallest rider who would fit on a size L, and also list the 6'3" rider as the starting point for the size XL. Again, pretty generic charts (and some companies don't even list them any more), but a good starting point.

    Niner Sizing Recommendations

    Many have echoed similar recommendations on this board that the Niner chart says - go down the size for quick maneuvering, go up for stability. I don't think the short chainstays and wheelbase of the Vertex XL would have you finding it lacking in maneuverability. And the best way to tell is a demo ride. It wouldn't hurt to demo a couple other brands in L and XL as well if at all possible. There must be some 29"er riders around your area who own the big bikes you could borrow.

    BB

  7. #7
    TR
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    Forget about whether it says L or XL or even XXL.
    If you are the same height as me with long legs (which you are), then you probably need a bike with a 25" ETT or longer.
    I used to squeeze onto bikes with a 24.5" ETT with a 110mm stem and broomstick of seatpost but now run longer ETT and shorter stems and a much more reasonable amount of seatpost.
    I dont subscribe to the idea that a smaller frame means less manouverability. Geometry does that. All a smaller frame brings is more fit issues.

    And because others are posting pics of themself racing on their bike, I will too.


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