July 23rd - Riding back home this evening, something shiny in the road caught my eye - lying on the edge of Green Lane in Shelfield, the debris from something that really shouldn’t happen. It’s a shattered bicycle sprocket.
This would have been part of the cassette, or rear group of cogs an the back wheel of a cheap bike. It’s been used, as the teeth are worn, and the chrome coating ground through. Decent sprockets are made from high-grade alloys or steel, with some flexibility. Generally, they’re pressed or forged.
This one is low grade steel, and has been made from cast material, making it inflexible and weak. It’s a fair assumption that under load, it’s cracked, and at some point catastrophic failure has occurred, and other debris in the road suggested as much.
Cheap supermarket or discount store bikes are often fitted with this kind of cheap componentry and fail in this kind of manner. Deprending on when it failed, this kind of breakdown could be very serious, and cause the rider to be injured - imagine if this had happened when cycling up a steep hill, like Black Cock Bridge, further on?
If you need a decent bike, and haven’t got much cash, a better option is to look out for a decent secondhand steed. You’d be surprised what you can get from Gumtree or the small ads for the same money.
A very, very cheap bike really isn’t worth the risk or hassle. They’re cheap because they’re made out of cheese, bus tickets and spit…