erig007

I see plenty of hidden weights that when put together can add up pretty fast:

-scale accuracy. Don't know much about digital scales but with analogic scales
(your weight + bike weight ) - your weight is not equal to bike weight
let's say you weight 200lbs, the scale has a 1% error
(200lbs + 23.6lbs ) +/- 1% = +/- 2.236 lbs
23.6lbs +/- 1% = +/- 0.236lbs

-the frame size +28g (seems small)
-if other people have rounded their bike weight
-air chamber weight and air weight
-bottle cage, bike computer, sticker etc weights
-weight variability between bikes
-dust on tires and grease on chain and cassette even if you don't see it
-everything i don't know like if all the other bicycle components are stock components, for your bike and other people's bikes you're comparing with. If the other guys have changed components like the saddle and tires for lighter one for instance then 21lbs is maybe 22lbs with stock components