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Why the big difference between calculated and advertised bike weights?

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  • January 27, 2017 at 1:15 pm #26717
    part_robot

    I’ve just been calculating the weight of a build using a Cannondale SuperSix Evo 105 as the basis. The bike weighs 8120g according to reviews but if I add up the weights of all the components I get nowhere near that. This seems to always be the case for Cannondale (whilst Canyon bikes typically add up to what you’d expect). Why is this?

    Here’s the breakdown:

    Wheelset: 1735

    Tyres: 460

    Tubes: 200

    Bar: 320

    Stem: 149

    Shifters: 486

    Rear mech: 234

    Front mech: 89

    Brakes: 378

    Saddle: 250

    Crankset: 600 (guess… it’s around the Ultegra mark)

    Cassette: 251

    Chain: 257

    Frame “system” (i.e. forks, frame, seatpost): 1600

    TOTAL: 7009g

    Conspicuously missing are the bearings and cables but even then I’m  at least  700g out. How? Same happens when I calculate the weight of the SuperSix Evo Hi Mod and my Synapse. Do they hide some lead blocks somewhere after assembly?

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Viewing 14 replies - 1 through 14 (of 14 total)
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  • January 28, 2017 at 10:43 am #885941
    0
    trohos

     90% of manufacturers give

     90% of manufacturers give their weights without pedals and with the smaller sizes of components.

    The weight you take from web may differ  up to 10%. Also the frames for the same model has a little variation in the weight.

    January 28, 2017 at 9:31 am #885939
    0
    Nick T
    part_robot wrote:
    Bike, frameset and wheelset from reviews. Groupset from a site that has all the groupsets weighed. Some other from blogs/forums. The rest from wiggle etc.

     

    You’re comparing claimed individual component weights to a claimed full bike weight and you wonder why there’s a discrepancy? No two components will weigh the same from the same production line, the advertised weight is usually best case scenario so add a few % onto the advertised weight before buying. 

     

    Youll only get an accurate weight for an item when you have the part on a set of scales in front of you

    January 27, 2017 at 9:55 pm #885937
    0
    rjfrussell

    If every item manufacturer

    If every item manufacturer has gone 10% low (what cads, they’d never do that, would they), you are there.

    January 27, 2017 at 9:14 pm #885935
    0
    part_robot

    Bike, frameset and wheelset

    Bike, frameset and wheelset from reviews. Groupset from a site that has all the groupsets weighed. Some other from blogs/forums. The rest from wiggle etc.

    January 27, 2017 at 9:06 pm #885933
    0
    Nick T

    Where are you getting these

    Where are you getting these component weights from 

    January 27, 2017 at 7:14 pm #885931
    0
    Giles Pargiter

    I really think that when one

    I really think that when one considers that people often pay over a £1 a gram to lose weight on their bikes – that is way outside margin of error territory. . . then again ..?

    I have noticed in the past that the labels one would expect to be are often not the lightest. I distincty remember weighing a Stronglight chain set against a Campag’ one and the Stronglight was over an ounce (28g) lighter, to my surprise.

    That in no way explains the divergence in weights mentioned though. Rather it adds to the inexplicable inaccurracies in advertised weights. Could be some kind of fraud maybe?

    January 27, 2017 at 4:28 pm #885929
    0
    mtbtomo

    Do the review(s) give actual

    Do the review(s) give actual weight or catalogue weight?

     

    The manufacturer might weigh an actual bike for a given size, and the component manufacturers do it differently (minimum weight of one from a batch of components)?

     

    5 – 10% weight discrepancy is not a lot.

    January 27, 2017 at 3:08 pm #885927
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    beezus fufoon

    did you weigh the air in the

    did you weigh the air in the tyres?

    January 27, 2017 at 2:19 pm #885925
    0
    HarryTrauts

    Grease.  300g of grease.

    Grease.  300g of grease.  Problem solved! smiley

    January 27, 2017 at 2:12 pm #885923
    0
    part_robot

    So if Natrix is right we are

    So if Natrix is right we are down to just 300g missing. I suspect that’s margin of error territory unless I’ve missed something else?

    January 27, 2017 at 2:11 pm #885921
    0
    part_robot

    Could be. There’s 200g right

    Could be. There’s 200g right there maybe! Good spot. Perhaps the other review included pedals (I don’t recall where I found it however)

    January 27, 2017 at 2:09 pm #885919
    0
    Natrix

    Frame size??  The review I

    Frame size??  The review I read had it as 7.9kg anyway http://www.cyclingweekly.co.uk/reviews/road-bikes/cannondale-supersix-evo-carbon-105-5

    January 27, 2017 at 2:01 pm #885917
    0
    part_robot

    Nowhere near;

    Doesn’t look like it:

    Bar tape: 50g

    QR: included (but I’ll add 170g just in case)

    BB: 100g

    Bolts: stem only not accounted for – 30g max I’d guess?

    Cables:  250g

    NEW TOTAL: 7600g

    STILL MISSING: 500g

    January 27, 2017 at 1:36 pm #885915
    0
    sergius

    Cables, Bar Tape, Nuts and

    Cables, Bar Tape, Nuts and Bolts, BB, QRs…

    700g really isn’t a lot of weight for all of those bits

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