Sizing up on a XC Bike- Mtbr.com
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  1. #1
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    Sizing up on a XC Bike

    My first mtn bike was a Large and every bike since then has been too. I'm probably 6' and a half inch. Blessed with longer torso and shorter legs than most. Recently I've been feeling cramped in the cockpit of my current ride. I've also wanted to swap out the fork from a 100 to a 120 which will shorten up the reach by another 10mm. I'm also liking the shorter stem on my trail bike and thinking about the same on the XC bike. That will make my bike feel even smaller.

    Given that, for my next purchase I'm thinking about going to an XL with a shorter stem for my next bike. Thinking maybe a 60mm on a XC bike. Has anyone moved to a larger size with the shorter. I think I've got enough standover and enough space for the short travel dropper.

    Yeah, I'm comparing reach and not TT length. But if there is something else I should be thinking about then by all means educate me.

    Comments, input, ideas?

  2. #2
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    I'm 6'2", and also have a long torso, and prefer XL bikes.

    Every time bikes take a step up in reach, I seem to be slightly happier with the fit/feel.
    Whining is not a strategy.

  3. #3
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    I see what your talking about, although your post leaves me a question. What are the geometry differences between your XC and your trail bike. A short stem on "very XC oriented" geometry may be an unsettling ride (at least that's was my experience on my XC bike.....I tried the whole "turn your XC bike into a trail bike thing") When I have the go-ahead from the other half, I've been seriously considering doing something like a "middle of the road" geo frame (68-69 HTA, 74-75 STA and a bit longer front end and short stays) but in a more XC/endurance build up (29er). Something like this may give you some needed reach, stable but "handle-able" and still have good climbing.
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  4. #4
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    Hi Riding29,

    From your description we have similar proportions being longer in the torso than the legs though I'm at the opposite end of the spectrum. I'm right on that dividing line between a S and M size frame. I went with the M frame with the longer wheel base and shortened the cockpit by dropping from an 80mm Stem to a 60mm and run my saddle just a tad (<5mm) forward of center on the rails. This is on a bike with a 69.5* Head Tube angle and a 74.75* Seat Tube angle. For me personally it has been a Win-Win.
    I think the bike handles better, still climbs like a mountain goat and I'm comfortable enough to do 35 mile 1 stop rides without feeling like I've been in some medieval torture device for two and a half hours. At my age that is a very important thing! LOL

    I can see the handling getting too twitchy like Joe said if you dropped down to something like a 45mm or shorter stem. The 20mm's I dropped actually made me feel more centered and balanced and not so strung out over the front end which on XC courses here in the desert SW (very rocky and a lot of loose on hard) is a very good thing. You give up a fraction of the Aero Position but gain a lot in the rough & tech.

    On the dropper I run a 125mm LEV Integra and absolutely love it. BUT, considering our height difference I'm not sure if that'll be any help at all.

    I hope this helps in your search for the perfect fit.

  5. #5
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    Id size up. Im about an inch shorter than you and all torso too. My best fitting bike is my new Pipedteam Moxie hardtail w 510mm reach. Best fit in seat, out of seat mashing, and DH. BTW, a quick test for pedaling bike fit is to move from sitting pedaling to standing and try to detect how much weight is awkwardly shifting or how much extra balancing you need. Good fits make this effortless.
    Unfortunately my FS trail/XC bike has 445mm. Any of my future bikes will be 480-520 reach.
    Note: standover/seat tube is important for trail use in my opinion too, so sizing up on a frame w high standover/seat tube might be a problem.

  6. #6
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    Quote Originally Posted by riding29 View Post
    My first mtn bike was a Large and every bike since then has been too. I'm probably 6' and a half inch. Blessed with longer torso and shorter legs than most. Recently I've been feeling cramped in the cockpit of my current ride. I've also wanted to swap out the fork from a 100 to a 120 which will shorten up the reach by another 10mm. I'm also liking the shorter stem on my trail bike and thinking about the same on the XC bike. That will make my bike feel even smaller.

    Given that, for my next purchase I'm thinking about going to an XL with a shorter stem for my next bike. Thinking maybe a 60mm on a XC bike. Has anyone moved to a larger size with the shorter. I think I've got enough standover and enough space for the short travel dropper.

    Yeah, I'm comparing reach and not TT length. But if there is something else I should be thinking about then by all means educate me.

    Comments, input, ideas?
    You're making wholesale statements about all XC bikes and sizing instead of being specific about YOUR current bike and whatever specific bike you're considering buying. Not all XC bikes fit the same at all.

    Modern XC bikes are getting longer in the Reach department while stems are getting shorter so depending on what your current bike is it may or may not be a good idea.

    The answer to your basic question of whether or not you can size up to an XL with longer arms and torso, probably yes.

    It would help a lot if you gave more specific details about your current bike and setup.
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  7. #7
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    Quote Originally Posted by *OneSpeed* View Post
    You're making wholesale statements about all XC bikes and sizing instead of being specific about YOUR current bike and whatever specific bike you're considering buying. Not all XC bikes fit the same at all.

    Modern XC bikes are getting longer in the Reach department while stems are getting shorter so depending on what your current bike is it may or may not be a good idea.

    The answer to your basic question of whether or not you can size up to an XL with longer arms and torso, probably yes.

    It would help a lot if you gave more specific details about your current bike and setup.
    Agree on the wholesale statements. Don't flame me. Just looking at trends and trying to get close on my next purchase. Test ride is everything, agreed.

    My RKT has a reach of 441 with the 100mm fork and I always had a 90/100mm stem. When I shortened the stem I liked the steering but like I said I felt cramped. I wanted to put a 120 fork on it which would shorten the reach another 10mm to 431mm. Wrong direction.

    So the RKT is now going to my son (fits him well) and I bought a new XL Oiz TR with a reach of 466mm. I think it is going to be perfect with a 60mm stem. It only has a 125mm dropper so I think I'm fine there. If it doesn't fit I have the option to get the large. I'll let you know.

    But in general, Large XC or XC/TR bikes all had a reach in the ~440 range. (yes I know every bike is different). And the generic sizing guess is that is for someone about 6'. I now see the new Santa Cruz Tallboy has a 470mm reach for a Large and a 50mm stem. Backs up my thinking. Yeah I know the TB is not a XC bike but wondering if the strictly XC bikes will follow. But on that Tallboy I would definitely be a Large and not an XL.

    Just seems to be a trend, and I guess my point is to be very aware of what the bike manufacturer has done with the geometry from version to version.

  8. #8
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    Back in the 90s and early 00s, we were told over and over again to not size-up, to down-size. But those bikes had goofy-long headtubes and crazy-high top-tubes. Modern geometry is much better and you don't take the huge handling and other hits that you used to by sizing up. It's worth noting that you will spend damn near ALL the time on the bike climbing and riding flat terrain. Sure, you may go downhill, but as a % of time it's a small fraction, even for an enduro bike, so the question is do you want to be uncomfortable nearly all the time, or comfortable the majority of the time? These days, the only thing I'd downsize when in-between sizes may be a full DH bike that will never see a day of uphill riding. There's also the structural concern with downsizing in terms of having to run more exposed seatpost. Min insert doesn't matter much when you increase the lever arm beyond what was intended.

    It's important to look more at reach and the combination of stem/bars that are on a particular bike build, but lots of people are still "programmed" to "always downsize" and it has pretty poor effects these days.
    "It's only when you stand over it, you know, when you physically stand over the bike, that then you say 'hey, I don't have much stand over height', you know"-T. Ellsworth

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  9. #9
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    Also remember reach is from cranks to top of head tube. It NOT from seat to bars. My 2019 Ripmo is Medium and so is my 2018 Epic. The Ripmo has a longer reach and ETT, but feels more cramped (ie upright when seated). This due to stem length. However the bikes are not the same and my Ripmo uses a more upright seating position for DH stability and confidence, but my Epic is more aggressive. The epic is made to go fast over short and long distances with quite a bit of that time in the saddle. The Rimpo is more biased to standing and descending position, but is forward enough to still climb steeps really well. So fit will be different on the bikes given their purpose. Personally I am 5'7" with longer legs and shorter torso so I use lots of seat post exposed in both bikes. One last thing to consider is that longer bikes tend to be more stable and shorter bikes more nimble. Given my leg length I am sure I could have "fit" on a Large Ripmo, but did not want to have that large of a bike. I don't do really fast DH stuff and prefer to have low speed control in tight places. My Epic I never considered going larger since I feel like it would be too long for comfortable seated position. I ride this bike in short races and 6hr races as well as 24 hour solo. Fit is pretty good on that bike.


    2019 Ripmo
    ETT = 603
    Reach = 447
    Stem = 60
    Stack = 623
    ETT+Stem = 507

    2018 Epic
    ETT = 595
    Reach = 426
    Stem = 80
    Stack = 597
    ETT+Stem = 513
    Joe
    '18 Specialized Epic 29", Vassago Verhauen SS 29", '19 Ibis Ripmo, XC, AM, blah blah blah.. I just ride.

  10. #10
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    I sized up on my Yeti SB100. Im 59 and according to there chart Im a med. I sized up to a large and couldnt be happier

  11. #11
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    Quote Originally Posted by JoePAz View Post
    Also remember reach is from cranks to top of head tube. It NOT from seat to bars. My 2019 Ripmo is Medium and so is my 2018 Epic. The Ripmo has a longer reach and ETT, but feels more cramped (ie upright when seated). This due to stem length. However the bikes are not the same and my Ripmo uses a more upright seating position for DH stability and confidence, but my Epic is more aggressive. The epic is made to go fast over short and long distances with quite a bit of that time in the saddle. The Rimpo is more biased to standing and descending position, but is forward enough to still climb steeps really well. So fit will be different on the bikes given their purpose. Personally I am 5'7" with longer legs and shorter torso so I use lots of seat post exposed in both bikes. One last thing to consider is that longer bikes tend to be more stable and shorter bikes more nimble. Given my leg length I am sure I could have "fit" on a Large Ripmo, but did not want to have that large of a bike. I don't do really fast DH stuff and prefer to have low speed control in tight places. My Epic I never considered going larger since I feel like it would be too long for comfortable seated position. I ride this bike in short races and 6hr races as well as 24 hour solo. Fit is pretty good on that bike.


    2019 Ripmo
    ETT = 603
    Reach = 447
    Stem = 60
    Stack = 623
    ETT+Stem = 507

    2018 Epic
    ETT = 595
    Reach = 426
    Stem = 80
    Stack = 597
    ETT+Stem = 513
    Joe, Im 5.9 or 1.80ish and I have 77cm from center BB to top of the seat, seatpost looks a lot out of the frame. what would be your meassure?
    Im using both L size cannondale fsi 2016 and specialized chisel 2019 with short stems (80mm) but considering, now they are longer in ETT terms, new epic ht or cannondale fsi 2020 in Msize, with 100mm stem

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