Bathroom Scales - How accurate are they?

Markta
Markta Posts: 767
edited May 2007 in Road beginners
Hi there,

Just trying to get an idea of the weight of my Trek Madone, so wheeled the bike vertically onto the scales to take a reading. I was a bit surprised to say the least when they said 16.8lbs!

I'm sure it's lighter than that (rather hoping). Was wondering whether anyone else uses them to do the same. The scales have only been used a handful of times and are the Hanson digital ones.

Logically, would just one wheel on the scales give an inaccurate reading due to the vertical load when compared to the bike being horizontal?

Thanks in advance [:)]

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Comments

  • greenmarkcp
    greenmarkcp Posts: 530
    depends on the scales, but I reckon your way of measuring the weight isn't really that easy

    Better to stand on the scales without the bike and then stand on them with the bike. Subtract one figure from the other and - hey presto - you have the negative of your bike weight.
  • Mosschops2
    Mosschops2 Posts: 1,774
    Unsure about whether this works for digitals particularly, but I understand that "normal" scales are most inaccurate at the extremes of the scale i.e. 0-1 stone, 18-19 stone (or whatever).

    Therefore when weighing stuff like airline luggage, I (still) stand on the scale first, and compare that weight to me holding the bag.

    If nothing else, you could try this, to see if there's any difference - which would tell you how accurate your scales are!!!!

    <font size="1">Have you ever tried pressing Alt+F4 ??</font id="size1">
    baby elephants? Any baby elephants here?? Helloo-ooo
  • Sheddy
    Sheddy Posts: 942
    Doh, ray, me, far, so, la, tee, do
    Should sound even better in the bathroom !
    Too much of anything is too much for me
  • I use the method of "me with object" - "me without object" to weigh bikes, luggage, folding kayaks, cats... I have the scales on a hard surface, not carpet, and I keep my feet in about the same position for both weighings. Seems to give consistent results.


    The older I get, the better I used to be.
    The older I get, the better I used to be.
  • giant_man
    giant_man Posts: 6,878
    Why are you surprised? My carbon bike is 16.1lbs so it's feasible I guess. Having said that i don't think bathroom scales are the best measuring scales to use.


    SIZE IS EVERYTHING! or at least that's what my LBS tells me.
  • giant_man
    giant_man Posts: 6,878
    <blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by giant man</i>

    Why are you surprised? My carbon bike is 16.1lbs so it's feasible I guess. Having said that i don't think bathroom scales are the best measuring scales to use. You won't get into the 15s with a Trek Madone!


    SIZE IS EVERYTHING! or at least that's what my LBS tells me.
    <hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">


    SIZE IS EVERYTHING! or at least that's what my LBS tells me.
  • mossycp
    mossycp Posts: 233
    Bathroom scales vary a lot. If you are comparing weights from week to week the scales have to be placed on a hard surface in exactly the same place, otherwise the results vary. If you are putting the bike vertically on the scales then you must be holding the bike up? That would affect the reading quite a lot even if you think it isn't. Best bet as everyone says is to weigh yourself, then yourself and the bike and take one from the other.

    You reckon it's lighter than 16.8lbs? Including pedals? That's light! I'd be surprised if it was much lighter than that unless you've got all the bling kit on it.

    If you really want an accurate weight then hang the bike from calibrated fishing scales.

    <font color="blue"><h5>Today is your day, your mountain is waiting, so get on your way {Dr Seus}</h5></font id="blue">
    Today is your day, your mountain is waiting, so get on your way {Dr Seus}
  • DavidTQ
    DavidTQ Posts: 943
    Bathroom scales I generally count as a guessometer they can vary even by you leaning forwards and backwards or moving your feet forward or back on them. They are only a rough guide at the very best, and being used in the manner you are describing likelly to be entirely out. How did you keep the bike up right on it rear wheel on the scales?
  • Positron
    Positron Posts: 191
    As mossy says domestic scales do vary. We've got some at home which are absolutely pants - very dependent on the surface they're on, neither accurate (give the correct value) nor precise (give the same value for repeat measurements).

    Luckily at work we have some dead expensive scales which are accurate (and precise) to less than a 0.5% error which do the job very nicely.

    p. (I find using a hose on the drive a better method of clearing the bike anyway...)
    Never order anti-pasta to arrive at the same time as pasta.
  • rosser
    rosser Posts: 25
    forget the bathroom scales and get some fishing scales - cheap, accurate and have a hook
  • Archcp
    Archcp Posts: 8,987
    <blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by DavidTQ</i>

    Bathroom scales I generally count as a guessometer they can vary even by you leaning forwards and backwards or moving your feet forward or back on them. <hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

    Aye. It takes a lot of perserverance to get the lightest result..[;)]

    If I had a baby elephant, it could help me clean the car. If I had a car.
    If I had a baby elephant, it could help me clean the car. If I had a car.
  • Mosschops2
    Mosschops2 Posts: 1,774
    Actually last time I used your scales Arch I thought they made me about half a stone too heavy!! [;)][;)][;)][;)]

    <font size="1">Have you ever tried pressing Alt+F4 ??</font id="size1">
    baby elephants? Any baby elephants here?? Helloo-ooo
  • Unless you've got very light/expensiv estuff on it, weight sounds about right, surely?

    I got a carbon TCR with mainly DA, carbon bars, stem, post and a 135grm saddle down to about 16.5lbs from memory. Cost me 1600 quid with nearly all 2nd hand bits (incl the frameset). To get below 16 would have cost at least another grand!

    d.j.
    "Like a true nature's child,
    We were born,
    Born to drink mild"
  • I had some Hansom digital scales and got fed up with their inconsistent results so I took Which? magazine's advice and bought a Weighfoolchers model instead. The latter tell me I am a bit lighter [:D] and seem to be more consistent, however whether they are actually more accurate is another matter. You would have to get of some standard weights and test them out and I am not really that bothered!

    PS I see T**T is automatically changed to FOOL
  • Fnaar
    Fnaar Posts: 1,985
    <blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Mosschops2</i>

    Actually last time I used your scales Arch I thought they made me about half a stone too heavy!! [;)][;)][;)][;)]
    <hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
    Try Arch without Mosschops, then Arch carrying Mosschops, for a more accurate result! [:D]

    <b><font color="blue"><font face="Comic Sans MS">kinckers kanckers konckers</font id="Comic Sans MS"></font id="blue"></b> [:D]