Recently my chain broke (when it comes off, I usually hook it partially on, and then rotate the peddles to make it go all the way on - I'm guessing this sideways pressure was beyond what it's designed to handle and led to it breaking - I didn't get to inspect it 'cause I had to run to catch the bus (right after my knee had jammed into the handlebar) and it was taken later). I note that a new chain on my old sprockets, causes the new chain to sort of ride up on the teeth of the sprocket and then jerk forward/backward (I can't remember exactly what happens). When I lined the old chain up against the new chain, I noticed that 10 links on the old chain was a shorter distance than 10 links on the new chain so I suspect this is the cause, rather than the chain-rings simply being worn. Unfortunately, I no longer have the old chain in my possession (I left it hanging over the pannier on my bike after it broke, and it had been removed when I went to inspect it the next day). So it seems, contrary to what Wikipedia says, there is no single standard size of chain (even if one is more common). The new chain that I bought was of the size 1/2 x 1/8. What do these numbers relate to (using a ruler, I can't match the dimensions to any of the numbers given. Can anyone advise where I can find a list of chain sizes smaller than this? I figure I can calculate the circumference of the sprocket and divide by the number of teeth to find the required size.
I'm not sure if it makes a difference but the bike is a Batavus Cambridge with a SRAM Super-7 internal gear hub but I don't know the date of manufacture nor how to determine it.
I don't really want to replace the sprockets because the front one is welded to the crank and I don't even know what misery the rear one has in store for me.