Shimano Dura-Ace BB-9000 Bottom Bracket
The Shimano SM-BB9000 bottom bracket features a 25 gram weight reduction over the 7900 plus a new black-anodized finish. To achieve this considerable weight loss the external cup size is noticeably smaller thanks to smaller bearings and a reduced external diameter.
Other than the smaller cup and bearing size, the system is still Shimano's well proven Hollow Tech II design with a 24mm internal diameter and the benefits of a wider bearing platform, easy installation and serviceability. Improvements don't stop at weight reduction. New bearings and seals allow a claimed 50% reduction in friction so your cranks will spin more freely plus there is no pressing need to jump to ceramics.
As side note - your standard outboard bottom bracket tool won't fit directly due to the smaller external diameter. But the good news is Shimano includes an adapter that nicely works with all the standard outboard bottom bracket tools. Select BSC (also known as English) or Italian threading.
- Choose from BSC-English or Italian threading
- 65 grams including sleeve
- Includes adapter for external cups tools
- New seals reduce friction 50%
- New, smaller external diameter
AnonymousPosted on 8/8/2015
Buy this because it's a great, inexpensive piece of engineering and it works as advertised. The fact that it saves a little weight over regular sized outboard bb's is just an added bonus. This is my third BB9000. Im finding that around 8,000 kms/5,000miles, is about the limit on them. You can push beyond that of course, it will still function ok, but you will REALLY notice a tremendous difference when you change it. So, durability might be an issue for some folks, but they are so cheap and easy to work with, for piece of mind why wouldn't you change it out frequently? Ive read criticisms of the plastic bottom bracket tool adapter that comes with the BB9000. My experience with the adapter is different. I found that it fits perfectly into my Shimano bb tool. After three new bbs and multiple deinstalls/reinstalls for cleaning, regreasing, etc, Ive never had a problem with the adapter, I am still using the first one even though you get a new adapter every purchase.
Pros Inexpensive easy to install; works as advertised
Cons Maybe durability