Stamped steel crank sprockets vs machined

[steve marino]

My bike's getting to the point where I will soon need to replace the driveline. My low end eBike has stamped steel sprockets on the crankset (all in one w/ non removable sprockets), and I see that the higher quality cranksets have sprockets that are machined. Is there any benefit to the machined sprockets? I never use anything other than the big sprocket, so getting away from the cheap stamped steel 3 sprocket arrangement appeals to me in the interests of just making things simpler. I'll need to spend more money for a crank set that features removable sprockets and pick a sprocket to go on it though.

I would imagine that the machined sprockets might wear better over time, and perhaps contribute to longer chain life since they seem to be made of wider material than the stamped steel sprockets that look awfully thin. Is that true? If there's no difference in wear between the two it may not make sense to spend the extra money for the higher end cranksets/sprockets.

 

[Ken M]

On an ebike, where weight is less important, you are far better off sticking with steel sprockets front and rear. They last much longer than the softer aluminum ones that any shop is going to push you towards to get your repeat business more often (beancounters never really are concerned with what is best for the customer). Chains typically wear out by stretching so the sproket material will not have an impact on chain life. Stick with steel!!!

The bike industry has been driven by a weight priority for 50 years which simply doesn't apply that much to the ebike segment. I guess is you are exclusively riding off-road there may still be some merit to having alumimum alloy spockets but the loads will wear them even faster with a mid drive.

 

[steve marino]

Thanks. That makes sense. I was concerned that possibly the narrower stamped steel rings might place too much load in the middle of the chain rollers vs spreading it our further with the thicker machined sprockets, but that's probably a non factor.

 

[Ken M]

On some cassettes you will see the smaller high wear chain rings made from steel and the larger one from Aluminum which is a clear tell on which material is more wear resistent. So long as you let them many shops will just put aluminum front and rear knowing you'll be back sooner for more service.