Originally Posted by
Ironfish653
It's an '89; started life as an R500, I repainted it in Kameleon green/purple, fitted a 2x10 drivetrain and 320tpi cotton racing clinchers. It wants "Full Gas" all the time now.
Yes and No; Yes, in that you are side-loading the hook, but that side-load is only ~20* off angle , but No, in that WRT hanging up a bike, the net force in the whole system is only equal to the weight of the bike. In a "dead hang", all of the force is on a single point on the wheel, and the whole thing is in tension. In a wall mount, the bikes' wheels are "pushing" against the wall, and the hook is keeping the bike from falling away from the wall as much as supporting its weight. Same net total of forces, just split up in a couple different directions.
Id have to pull out my old Statics notebook to get you an actual breakdown, though.
The nail-pulling example also brings biomechanics and levers into the equation, which increases the variation in the amount of force you can apply to a given point in the model. Unless you're putting the bike on the hook and then hanging from the handlebars, that just muddies the water.
I stand by my original statement though, that the anecdotes of damaging bikes by hanging them is because they were hung with the hooks against/around the spokes, and loaded or unloaded by trying to pull the bike "down" off the hook, rather than lifting it clear of the hanger, then bringing it down. I will agree though, that a wall mounted hook takes a bit more care, both in setup and in use, than a single ceiling hook.
I agree the weight is not much for a typical bike. But the loading is different. The weight of the bike is being exerted straight down at the axle of the wheel being hung, and you then have that moment arm, the wheel radius to the wall, to exert a torque. Now take that same torque and divide by the distance from the tire contact point at the wall, and the vertical distance upward to the hook; If that distance is small, you have a force magnification. The hook also experiences shear and bending loads, because even though the tire has contact with the wall and has friction, the tire can roll (EDIT: I have to think about this... it can roll when first hung... need to think about this), so none of the vertical load is being taken by the tire, it is all a downward shear and bending on the hook at 90 degrees to its intended load direction. But it can handle that. But whatever outward pull of that force magnification, is harder pull on the rim at the hook contact point, and possibly an actual point with deep section rims, so for lightweight rims like carbon race rims, I'd do a quick calc and check the force magnification versus a pure vertical force hang on a hook.
The bike looked familiar; Mine is an '89, I think R600 (sorta) that I had them add the aluminum fork and the 7 speed cassette. I guess I have about 70k miles on that bike before going into storage in favor of townies. Loved the sportiness of it, was my first good bike, but over the years I didn't like the stiff ride, eventually fit I think 28mm tires that just barely fit with a file dusting of the front derailleur, and a triple crank when I moved from flatland to gentle hills for work. Bike still looks like new. 3rd set of wheels, due to fatigue cracks at spoke holes from the miles, roads were smooth.