I am trying to install a new 105Di2 crankset into an Shimano Durace BB and I am having a hard time pushing it though. Looks like it gets stuck with about 1cm to full install. Does it matter if I try to do it with BB installed or outside the bike. Same thing happens.
I have read about freezing the crankset and allow the spindle to "shrink" a bit then grease up and hammer it in? Seem pretty harsh solution, and then what about getting it out?

I would do as you propose, freeze, grease and rubber Mallet (not like a mad man)

Shimano BBs are tight for adequate weather sealing. A rubber mallet with a towel on the crankset and gentle taps should get it through.

Quote from: jonathanf2 on November 20, 2025, 12:25:55 PM
Shimano BBs are tight for adequate weather sealing. A rubber mallet with a towel on the crankset and gentle taps should get it through.

Yepp that's the way to go, it's normal a tight fit on shimano spindle, had same issue with ultegra bb on the first installation.

Quote from: alfiomotrambo on December 12, 2025, 05:19:12 AM

Yepp that's the way to go, it's normal a tight fit on shimano spindle, had same issue with ultegra bb on the first installation.

So how did you get it in? With a mullet or freezing or both?

I once had to resort to an aluminium preload bolt to pull a Shimano crankset spindle all the way through a narrow bottom bracket. Replaced the metal preload bolt with the original plastic one once I got it through.

Quote from: crazyravr on December 12, 2025, 08:26:19 AM
So how did you get it in? With a mullet or freezing or both?

I use a mallet with a towel on top of the crankset (avoid tap the crank surface directly) some tap went straight through

I once had so tight axle bb combination that I was afraid to hammer it in/out on a carbon frame so I lightly sanded the hole a bit bigger, didn't take much. I think it was Ultegra BBR-60 bb.

Freezer, grease, mallet and a lot less f WTF am I doing thoughts but it went in. Hope the seal is that good so I won't have to now try removing it.