 06-May-2006, 08:13 | #11 | |
| Registered Forum User Mille Bikes: 996 sps foggy, 2001 r6, 1098S, s1000rr, Panigale 1199S  Posts: 248 Join Date: Jul 2005 Location: newcastle Mood: on the back wheel !! Quote:
OK then, i'll ask you some more questions to make you think about this one ... 1.pressure ? I think you should think more of compressive stresses in the sprocket material. 2. The sprocket is still transmitting the same power, but at a slightly different RPM (as you have altered the gearing)...so what about thermal stresses ? think of this... sprockets are transmitting power through friction..friction causes heat.... and the original sprocket was of larger diameter, ie larger surface area, and can therefore dissipate this heat more efficiently. So now you go down one tooth and the diameter is smaller, ie the surface area is also smaller, so the sprocket theoretically is hotter, then the larger one. Now think of this.... some of that heat is dissipated through windage...ie as the sprocket rotates, air is passed over its surface, and cools it. However some of that heat travels along the drive shaft, and is dissipated through radiation, convection, so surely the smaller sprocket therefore transmits more heat along the shaft...have I got you scratching your head yet. Next time you come back off a ride, touch the rear and front sprockets, and tell me what you find ? We have to think of thermal stresses as well as mechanical ones ! From your quote, you are saying that there is agreater stress on the 'tooth' but surely the teeth are of the same form shape and size as the larger sprocket...arent they ? Of course they are, but we may not have the same number of teeth in contact with the chain as we would with a different size sproket.....  | ||
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