European Bottom Bracket Install Step 10

Now install your first cup. This step should be messy with grease all over. The amount of grease you have applied should allow for the cup to be hand tightened until the cup is flush to the frame. Do not force it. If it feels wrong, it is wrong. The cup may have been offset and cross threading if it will not thread in easily. Start over, make sure you catch a good start in the threads, if you ever second guess things may be going wrong, assume they are. Threads can be damaged, forcing you to have the frame chased and lose valuable thread thickness in the process. You may have to use a wrench towards the end of hand tightening as the cup gets very close to final contact with the frame. However, the force applied should be very minimal. More of a finish with a wrench rather than a tightening with a wrench.