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Pitfalls of buying too big ?

RandGRandG Posts: 779
edited December 2012 in MTB beginners
OK, simple question I guess, but what are the pitfalls of buying a bike that is too big for you ? I don't mean by miles, but for example, if you're a medium but the bike you're keen on is a large.

Posts

  • nicklousenicklouse Posts: 81,520 Lives Here
    to stretched. the big does not do what you want. even less stand over. just not a good idea.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
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  • RandGRandG Posts: 779
    Hmmm...looking add the geometry, the TT is exactly the same as my fs medium, but the seat tube is considerably longer as is the head tube
  • The RookieThe Rookie Posts: 27,747
    Are you looking at the top tube length or the EFFECTIVE top tube length (measure horizonatlly from headtub to an imaginary extended seat tube) which actually defines the size? A more downward inclined top tube will be longer for the same effective length.
    Seat tube will be loger it used for the equally meaningless seat tube length (from BB centre) to determine quoted size.

    A longer head tube will raise the bars, all else being equal, compared to a shorter one.....
  • miss notaxmiss notax Posts: 2,823
    Personally, I would consider buying a bike a bit too small but not a bit too big :?

    It's pretty easy to make a small bike a bit bigger and it still feels nice and easy to jump about on - if a bikes too big it throws everything out and it's more difficult to make it feel smaller when - essentially - that's just the size the frame is!
    Life is not measured by the number of breaths you take, but by the number of moments that take your breath away....

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  • If you value your testicles i would check the stand-over height, just to be sure.
  • nicklousenicklouse Posts: 81,520 Lives Here
    If you value your testicles i would check the stand-over height, just to be sure.
    sorry but standover height is a thing of the past.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • AlibranAlibran Posts: 370
    nicklouse wrote:
    If you value your testicles i would check the stand-over height, just to be sure.
    sorry but standover height is a thing of the past.

    Personally, I prefer a bike with some standover height. I don't much fancy being perched on the top tube with my feet off the ground.

    In my opinion, it's better to have a frame that's slightly too small than one that's slightly too big. As miss notax said, if it's a bit small, it's easy enough to make it feel bigger, but a frame that's too big will always mean the bike's too big. If I'm on a bike that's too big for me, I never feel like I'm really in control.
  • I have two bikes (well more or less one and a half now), the first is a Giant and I bought a frame that would classically be called "to big" for a MTB. This was partly deliberate and partly because it was all that I could afford. However, what it was brilliant for was going fast on relatively flat terrain really comfortably.
    What it is censored for is turning. The bike's geometry is simply wrong for me to use on trails and tight stuff.

    To put into context it is a 21" frame my MTB proper as such is an 18" frame.

    On a lesser note I would loose my testicles if I slid of the seat on the Giant so I am uber careful on it :oops:
    When God gave out brains I thought he said trains, and I said "it's OK I already have one".
  • The RookieThe Rookie Posts: 27,747
    Alibran wrote:
    Personally, I prefer a bike with some standover height. I don't much fancy being perched on the top tube with my feet off the ground.
    Which will rule you out of buying 95% of FSers on the market (probably).....

    As stated, a size too small is rideable, a size too big is not for an MTB although my daughter rides an 18" MTB frame as her commuter (to get her stretched out) her MTB is a 13.5".
  • There's a school of thought that says a smaller frame is better as it is more 'flickbable', however it seems that larger frames are now more popular as they are stabler and fits the current trend for short stem/wide bars. If you're between sizes and opt for the smaller frame, you are limited in the stem length you can put on it. This is the situation I was in, in the end I sold the medium and went for a large which is perfect. Of course, if the bike is clearly too big for you then that isn't good either.
  • AlibranAlibran Posts: 370
    Alibran wrote:
    Personally, I prefer a bike with some standover height. I don't much fancy being perched on the top tube with my feet off the ground.
    Which will rule you out of buying 95% of FSers on the market (probably).....

    It's a good thing I don't want one, then. I have plenty of standover on my 13" hardtail.
  • RockmonkeySCRockmonkeySC Posts: 15,247
    The idea that a smaller bike is easier to throw around and ride faster on descents is bollocks. Just take a look at any downhill bike, they are huge, they have long top tubes and massive wheelbases but are easy to throw around.
    The correct size bike is the one that's easiest to ride fast and throw around. A frame which is too small puts your weight too far forwards, will feel unstable at high speed, you won't have the length in the frame to move around properly when you use proper cornering techniques. It also doesn't work for climbing, the short top tube puts you in a more upright position which moves your weight back and makes to front too light. You can fit a longer stem & lay back seat post but they both cause other handling problems.
    My On-One 456SS is a size too small because I originally bought the frame when I didn't understand what I needed and I have never felt comfortable on it, I had a ride on a friends bike, same frame but a size larger and it was a huge improvement.
  • TorresTorres Posts: 1,266
    The idea that a smaller bike is easier to throw around...
    ... is exactly why jump bikes come in tiny sizes and BMX's are smaller still. :wink: However the rest of your post makes sense.

    In an idea world you should get a bike in the correct size, however I agree with Miss Notax that it's easier to make a little bike big than a big bike little.
    What We Achieve In Life, Echoes In Eternity
  • As I discovered first hand with my first bike, which was too big, it mostly restricts your ability to move around on the bike. In my case it was too long, so it meant I struggled to get my weight back as my arms would be at full extension too soon.

    With normal attack position it also meant my weight was too far forwards, so I found it impossible to manual it (still struggle now with that to be fair), but I could hardly lift the front wheel on my previous bike, simply because I was always too far forwards on the bike.
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