Originally Posted by
FBinNY
Yes, using smaller sprockets shortens chain life.
2 reasons for this.
1- driving torque, both input and output, is the product of sprocket radius and chain tension. So any system using small sprockets to achieve a given gear ratio wii have the chain running at higher load.
2- smaller sprockets cause the links to bend more as they wind onto and off the sprockets. More flex = greater wear.
This is why it is SOP in industrial applications to use the largest sprockets practical to the situation.
Yup. And the post that says "small wheels have to make more revolutions" is completely irrelevant. It's how many "engagements" of the chain and cogs / chain rings not how many wheel revolutions. To get the needed gear ratios with small wheels, they use small cogs on the cassette and that means faster wear. Whether this is the source of the OP's issue is not clear because if the gears are worn that would have a bigger effect.