Originally Posted by Spud Rider
Another factor to consider is possible interference with the chain guide and/or chain guard when using 45T, or larger sprockets. Also, the larger sprockets might cause accelerated wear of the chain guide slipper, part #9 in the following diagram.
This chain guide slipper have to be reversed when using a 42t.
I guess i would simply remove it with a lager sprocket, unless i can find a suitable aftermarket part.