How to replace a bottom bracket

In the quest for lower gearing, I’m considering replacing Kuroko’s crankset. The current one is a Shimano 105 compact, and it’s already got the lowest inner chainring available at 34 teeth. A subcompact crankset would let me go to 30 teeth, for a reduction of almost 12%. (BikeCalc’s gear inch calculator puts the difference at just under 11%.)

The Rolls-Royce model is the K-Force Modular from Full Speed Ahead, a gorgeous unit with hollow carbon fibre cranks.

K-Force Modular
K-Force Modular

The change requires a replacement of the bottom bracket as well. Kuroko has a press-fit BB86 model, and this is the FSA model required to fit the crankset. I’ve been thinking about this for a few weeks now, and one decision I’ll have to make is whether to pay for the shop to make the swap for me or to do it myself. With that in mind I started looking for how-to videos, and a few surfaced.

This first one is specifically for the BB86:

This one is a bit more long-winded but covers things in a more generalized fashion:

Nice to see him using all Park Tools in that, including the hammer …

From the videos it does look like something I could handle (although I’ve probably just got my DIY genes riled up by watching too many restoration videos), as long as I get a couple of specialized tools. So the next question was how much those would cost. The Shimano tools mentioned in the first video are available from Amazon. The removal tool is about $50 and the bearing press is about $45.

Park Tool of course has alternatives, and they even have this thorough guide. The BB Bearing Tool Set BBT – 90.3 is about $55 and the Home Mechanic Bearing Cup Press is more than $90. (I don’t think I need the $230 bearing press used in the second video, or the $30 hammer.)

Park Tool Home Mechanic Bearing Cup Press
The Home Mechanic Bearing Cup Press is kind of cute, though

So now the question is whether I want to spend $100 for tools that I may only use once, in order to avoid spending $100 for the experienced mechanic at the shop to do the work.

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