Originally Posted by Sheldon Brown
No, this is not good practice on- or off-road. Arguably it's even worse on MTBs because they generally use smaller chainrings which are more stressful, and 11 tooth small rings which wear faster.
Hmmm...I'm not sure I'm understanding this.
My chainline is fine using my big chainwheel and the highest (smallest) cogs. My chainline is also fine using my middle chainwheel and the highest (smallest) cogs.
Why is it bad if I am in big (up front) and small (out back) and decide to shift my chainwheel only from big to middle? Again, my chainline is still fine with this combination (using outboard XTR BB bearings).