Marie Attoinette Fan
I just close my eyes and hope for the best
If you sat on a pair of scales on top of your saddle, and it said 70kg or whatever when you were stationary, as soon as you started pedalling it would show less than 70kg because some of that weight is now being supported by your legs - because there is resistance when pedalling, some of the power generated is used to push the pedal down and some of the power is used to push your body up (or slightly backward sometimes). If you pedal really hard you'll find it only takes a little more power to lift off the saddle completely.I don't agree with the first paragraph. The weight should be on the saddle as it is the power one's leg generates which is transferred through the pedals to create motion.
If weight were a factor then heavier riders, on a flat route, would be faster. Weight is only a factor in descending because it increases impetus but it doesn't increase power, often the reverse in fact.
when pedalling normally there will always be weight taken through the legs, reducing the load on the saddle, unless you're pedalling at a super-high cadence? Any resistance from the pedal to being moved will result in the leg bearing weight and reducing the weight through the saddle.
As @Twilkes has said and then restated, if the rider applies a force downwards on a pedal and that's more than the force (if any - none on downhill) they apply upwards with hands on the bars, then the net weight supported by the saddle is reduced. I am disregarding any upwards force on the pedal moving upwards as it's negligible (and poor technique). Fisyks, init?I don't agree with the first paragraph. The weight should be on the saddle as it is the power one's leg generates which is transferred through the pedals to create motion.
Your own figures support the point I was making. I can't define what you mean by "most" but imagine it is more than one-third. By definition "most" must be more than 50% and I suggest it means much more than this figure. The link shows 45-50% of body weight supported by the saddle, 20% hands and 16% each leg. From your own figures +/- 70% of body weight is not supported by the legs. If "most" of one's weight is supported by the legs when freewheeling I feel the position is incorrect.When cycling normally most of my weight is on my feet, some on the saddle and a little on the handlebars.
Yeah the Sheldon Brown link essentially says that. I've found that on slow doddery rides my saddle hurts way more than on a long fast ride because there's far less power going through the pedals, so more weight on the saddle.Another thought/theory ...
With fresh legs, the body weight is shared between the contact points and a % taken up by the legs.
On longer rides, the legs begin to tire and the % weight share transfers more to the saddle, thus increasing saddle soreness on the longer rides.
Don't think I have suggested that "using one's legs to support body weight on a bike is" either necessary or efficient when riding along normally, nor that a road cyclist puts "most of [their] weight on the pedals" (and @Twilkes has resiled from "most" now). So I can see why you don't follow those arguments (as you have rephrased them) - I wouldn't agree with them either. But if a rider pedals (puts force on the pedal) then the 'equal and opposite' force on the body is upwards and that reduces the upwards force of the saddle on the rider's backside (NB bit more complex because of hands/bars interaction - see my earlier post). Riders aren't deliberately supporting their body weight with their feet when riding along normally, they are just pedaling: physics does the rest. No 'work' or 'power' without 'force'.I'm afraid I don't follow either of these arguments. The point of a saddle and it's position is to support the rider's weight. Using one's legs to support body weight on a bike is both unecessary and inefficient.
The sitting bones support the body and the legs do the work. Putting most of one's weight on the pedals suggests the riding position is wrong. The only time the legs support the body weight should be when standing on the pedals.