What saddle rail clamp should I get? I just got a new supercycle bike that came with everything, including the saddle rail clamp (the part connecting the double-railed saddle to the shaft beneath). After riding about 20km on it, the bike seat began tilting backwards randomly, without me adjusting it. I took it apart and found that the ridges on the insides of the saddle clamp had been ground down, and that the whole thing was useless. So far, I've only found one rail clamp that fits with both my saddle and the shaft underneath, and that's the exact same clamp as the first one. Is there another better clamp that won't wear down as fast as my initial one did?
Those style of saddle clamp only slip like you described if they’re loose. Make sure you tighten the side bolts really good (it’s hard to break those things) and use threadlocker.
A better option is to buy a 2-bolt (also known as “infinite adjust”) seatpost. Those use a better design where that slippage is not possible. Simple aluminum posts are not too expensive. Make sure you get the right diameter and length for your bike.