2014 Giant TCX: Press-fit bottom bracket replacement

It started with clicking as I pedaled away on Hyro aboard the indoor trainer.

It was always on the drive side, and it corresponded with applying downward pressure on the cranks from just beyond parallel to the ground. I wasn’t totally sold on it being a bottom bracket problem yet, as I could get it to go away with slight changes to my pedaling stance and force application on the pedal face.

The clicking got to a point where it became a regular occurrence and could no longer be ignored. One Saturday morning, I decided to finally get around to replacing the bottom bracket. Perhaps I was unconsciously putting it off, daunted by the procedure, but I suppose there’s a first time for everything. After all, it had been seven years on this current one.

At least I was prepared; I had a smattering of tools already in storage for this job. Accessing the bottom bracket always necessitates removing the crank, so I did just that. I would also need a new bottom bracket and the tools for removal and installation. A Shimano BB71-41B unit had been in my tool closet for years, and so was my Wheels Manufacturing PRESS-7 universal bottom bracket press and Park Tool BBT-90.3 tool set for BB86/BB90/BB92/BB95 applications. I had just never gotten around to using all of them until now.

With the crank out of the way, hammering out the old bottom bracket came next. Half of the BBT-90.3 is a remover tool, which is a steel tube closed at one end, and open with four flared fingers at the other. You push the remover tool through the bottom bracket shell, compressing the fingers until they go through the inside of the bearings and snap back into their flared-out position. Then you take a hammer and bash away at the tool’s closed end, its fingers pushing on the bearing cups with each blow until they fall out. I won’t lie – this feels totally wrong.

After some percussive persuasion, I got the old bottom bracket out and performed a postmortem inspection. Sure enough, the non-drive bearing still spun smoothly, but the drive-side one had telltale rusty brown traces in its inner race, and the whole thing felt rough and gritty to spin. This bottom bracket was truly well past its prime.

At this point I could now see into Hyro’s bottom bracket shell. As it had housed seven-year-old dirt and grit, it needed cleaning in preparation for the new bottom bracket, . A smearing of fresh grease later, it was now ready to accept a new bottom bracket – and time to truly test the PRESS-7.

Check out that funky green Shimano grease

While Wheels Manufacturing don’t recommend using the PRESS-7’s universal bottom bracket drifts for anything other than their own bottom brackets, they matched up nicely with the Shimano BB71-41B, carrying the bearings by their inner races. After assembling the tool inside Hyro’s bottom bracket shell, it was just a matter of turning the handles inward until the bearing cups sat flush on the lip.

Once the lip on the bearing cup meets the bottom bracket shell, you are done.

They got pressed in smoothly, simultaneously, and straight. Couldn’t really ask for more than that.

All that’s left is to reassemble the crank and ride the bike again – now free of clicking, creaking, or otherwise discordant noises as I pedal.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.