Dumbest things I've been told:
- Bike weight doesn't matter. This comment invariably comes from some old guy whose 30-pound bike is bristling with impediments such as racks, fenders, riser stems, obsolete electronics and a (shudder) kickstand;
- Fatter road tires are faster than the old skinny tires. Maybe, if you are comparing 23 vs. 28mm Conti 5000's both pumped up to 110 psi. But you pump the 28mm tires up to 80psi, and now they are slower;
- Disc brakes overall make you faster, since you can descend faster. This was actually told by a shop salesman, so I suppose it doesn't count as being conflicted advice.