Mountain bike size

Discussion in 'Mountain Biking, Trials and BMX' started by Alan Farroll, 10 Aug 2018.

  1. Alan Farroll

    Alan Farroll Well-Known Member

    Hi,

    I have a hard tail mountain bike but seriously considering investing in a trail/xc full suspension. A local shop has this model below at a reduced price but it is a 19inch frame which I think is a size large and not medium. I have had a sit on it and when standing over the bike there is very little clearance between myself and the top tube. I am 5’11” or 180cm tall with a 32 inch inside leg. I am concerned the bike is too big for me. Is that the case and should I look for an alternative with a size smaller in frame?

    Thanks in advance

    https://www.merida-bikes.com/en_int/bikes/full-suspension/all-mountain/2017/one-forty-700-6343.html
     
  2. Threevok

    Threevok Über Member

    Location:
    South Wales
    If there is very little standover, then I suggest you look at a smaller frame

    19" isn't always a large - some bikes (like an Orange Crush for example) 19" would be classed as a medium. Some other brands have 17" as a medium.
     
    meta lon likes this.
  3. Sharky

    Sharky Veteran

    Location:
    Kent
    Is your old bike comfortable?

    Start by taking measurements of all the relative contact points
    - saddle to pedals
    - saddle to handlebar grips
    - height difference between grips and saddle
    - fore/aft position of saddle relative to bottom bracket

    Then compare with the new bike. If you can achieve the same positions on a smaller frame, then go for the smaller frame.
     
  4. meta lon

    meta lon Guru

    Location:
    pboro
    If it's a nut knocker it's too big.

    I tend to get small 16 frame size even though sizing says medium 17-18
    I find them a stretch.

    But my medium commencal was a bit small ....it's all about riding and trying I'm afraid.

    I've stopped bying off the net,I go to Rutland Cycles and test ride now.
     
  5. Jody

    Jody Über legend of a forum GOD!

    Take it out for a ride and see what it feels like. My Anthem is a small (16" and i'm 5'5) and my knackers rest on the top tube if stood in the middle even though its sloping. But the bike itself is perfect in terms of riding/handling.

    The most important part is that you're not stretched out or cramped in the cockpit. Slight changes can aways be had after purchase with riser bars, stem length, spacers on the steerer etc.
     
    meta lon likes this.
  6. OP
    OP
    Alan Farroll

    Alan Farroll Well-Known Member

    Thanks everyone for your feedback. I visited another shop yesterday and sat on an 18 inch and it was just touching my groin so I think I should sway towards caution and get a 17 inch.
     
    meta lon likes this.
  7. SkipdiverJohn

    SkipdiverJohn Über Member

    Location:
    London
    17" seems very small for an adult bike to me - I'd regard that as a child-size frame, and I'm not much bigger than the OP although my legs are a bit longer. I've got two (old-school rigid) MTB's with 23" frames and get on fine with these for general riding, although I tend to ride a 21" frame on gravel and dirt tracks in woods, for the obvious reason. Sizing seems to have got rather silly in recent years, most modern bikes I see these days look too small for the rider - like they've borrowed it from their little brother!
     
  8. FishFright

    FishFright More wheels than sense

    [QUOTE="SkipdiverJohn, post: 5346839, member: 56288"]17" seems very small for an adult bike to me - I'd regard that as a child-size frame, and I'm not much bigger than the OP although my legs are a bit longer. I've got two (old-school rigid) MTB's with 23" frames and get on fine with these for general riding, although I tend to ride a 21" frame on gravel and dirt tracks in woods, for the obvious reasons. Sizing seems to have got rather silly in recent years, most modern bikes I see these days look too small for the rider - like they've borrowed it from their little brother![/QUOTE]


    Not for a frame with sloping geometry
     
  9. Blue Hills

    Blue Hills Guru

    Location:
    London
    As fishfright says, things are a bit more complicated with modern frames and sloping top tubes. I have bikes of several nominal sizes and all fit in terms of riding comfort and that dreaded but useful term "cockpit". I have an old faithful Ridgeback with a sloping top tube which someone on a ride told me was too small for me but in truth it has always ridden just fine. I have checked and although it has a lot seatpost shwing it is not beyond the safety limit. In size it is also I think very close to my old Dale fast city bike. That also rode wonderfully sat on it even though I must admit that sometimes when I approached it from afar, seeing it parked/lockedf, it did look curiously small.

    Beyond sloping top tubes, the matter is further complicated by the fact that different companies measure bikes in different ways - from the centre of the BB to the top of the top tube, to the middle of the top tube, or to the top of the seatpost on the frame. And, dammit, I have even discovered that Ridgeback changed its system over the years. I had always thought that that old Ridgeback was a 19in. Merasured to the top of the seat tube. But I now understand that when the bike was made, mid to late 90s, they measured to the centre of the top tube where it hit the seat-tube. So in those terms I gather it is more like a 17 or 17.5 inch. I have since acquired another different Ridgeback of similar age which is 19inches to the middle of the top-tube. Also rides fine and maybe looks better/more conventional. Also sloping top tube. Both of those bikes are 700C wheels but as 90s hybrids have a certain MTB heritage.

    More recently I bought a Ridgeback Expedition. 26 inch wheels. Slopinmg top tube. That believe it or not is classed as large and is said by Ridgeback to be all of 57cm. But I gather that they are measuring that to the top of the frame's seat-tube. I tried this size and the one below (maybe 54cm) and surprised the shop by going for the bigger one as they expected me with my height of 5ft8 to 5ft 9 to be a 54cm. I musty admit that I partly chose the bigger one as it sort of looked betterv as I admired it from afar across a darkened room :smile: Although initially I feel slightly sat on top of it rather than in it compared to some of my other bikes, it rides just fine. And carries my ton of camping gear very well.
     
    Oldbloke likes this.
  10. Oldbloke

    Oldbloke Guru

    Location:
    Mayenne, France
    I'm the same size as you; bought a Giant Fathom hardtail in size large last year as recommended by Giant dealer. Although it felt ok on test ride I found it way too big offroad, too stretched even with a short stem. Recently sold it & bought a Merida 96 XT full susser size medium, fits perfectly. My first Merida which I can highly recommend; good luck with your search!
     
    Blue Hills likes this.
  11. screenman

    screenman Legendary Member

    My 29er has no standover room, in 2 years of riding mainly off road it has never been a problem.
     
  12. Blue Hills

    Blue Hills Guru

    Location:
    London
    I'm not an MTB rider but from what I understand smaller is often better for serious off road stuff. If I'd been contemplating serious downhill athletics on my MTB-heritage Expedition bike (see above) I think I would have gone for a smaller frame.
     
    Oldbloke likes this.
  13. fossyant

    fossyant Ride It Like You Stole It!

    Location:
    South Manchester
    Also, when picking frame, make sure there is enough exposed seatpost to fit a dropper post should you wish to get one. They have a minimum insertion measurement. Each one is different though, but if you've not got much exposed seatpost, you won't be able to fit one.
     
    Oldbloke likes this.
  14. Blue Hills

    Blue Hills Guru

    Location:
    London
    On modern bike frames, I was also encouraged that that 90s Ridgeback (and the dale) weren't all that bonkers when I saw the cover of this book.

    https://www.ebay.co.uk/p/Adventure-...Stephen-Lord/89733063?iid=302493897446&chn=ps

    Dig the shamefully exposed seatpost on that skipdiver :smile:

    Also worth considering, to appreciate how academic this can all be, what would the measurement be of a brommie?

    Or this:


    I have both of those bikes.

    Positively obscene amount of seatpost being flashed.

    all the best
     
  15. SkipdiverJohn

    SkipdiverJohn Über Member

    Location:
    London
    That's just wrong, way too much. I don't tend to apply the same standards to shoppers/folders, but on a conventional frame I reckon anything much over 6 inches of seatpost on show looks weird and to my eyes, says the frame is undersized.
     
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