Why do a good number of bikes equipped with BB30/PressFit type bottom brackets develop creaks? Well, there can be a number of causes.
• If the hole through the frame’s bottom bracket is not absolutely perpendicular to the frame, then the crank axle will be slightly angled. That angled crank passes through bearings that are parallel with the frame and the resulting twisting force can result in a creak.
• The hole in the frame may not be perfectly round or may be ever so slightly big compared to the bearing. Either way, if the bearings are not securely and squarely set in the frame, creaks are more likely to develop. This is why many manufacturers recommend using a retaining fluid, such as Loctite 609, that can fill in gaps when installing BB30/PressFit bearings.
• Use of separate crank adapters when using a smaller 24mm crank (Shimano, SRAM GXP…) axle with a bigger 30mm bearing can also contribute to creaking.
The good news is that better solutions to all of these contributors are available today than just a short time ago.
The first product we found that virtually eliminated the chance of creaks in BB30/PressFit frames was the Praxis Works Conversion Bottom Bracket. As described in our previous article about this product, the Praxis Conversion Bottom Bracket is a two piece alloy shell that screws together. One end of the non-drive shell incorporates a collet design. When the two sides are screwed together, the collet expands, wedging the insert firmly in the frame. So, the bottom bearing insert is held in place two ways – by clamping against the frame’s bottom bracket shell, and by wedging inside the frame.
The only drawbacks to the Praxis offerings are as follows:
1) Limited applicability. The Praxis Conversion Bottom Bracket only fits BB30, PressFit 30, and Specialized OSBB frames, and only converts such designs for use with a Shimano, SRAM GXP, or Campagnolo Ultra Torque crankset. Praxis does not make a bottom bracket for use with a 30mm crank, nor can it be used in a Cervelo bicycle with the BBRight bottom bracket design and some other designs.
2) The Praxis design may have fitment issues on some bikes with internally-routed Di2 cables.
This being said, where a Praxis Conversion Bottom Bracket fits, it is a great product that we have used many times with great success. The Praxis comes with either steel bearings or ceramic bearings, both from Enduro.
Wheels Manufacturing has a comprehensive line of bottom brackets inserts comprised of a two piece, threaded alloy shell. These two pieces thread together in the middle of the bike frame, using a specific tool. As with the Praxis, this prevents misalignment of the bearings, and corrects for frame construction that may not meet the extremely tight tolerances that are required. The Wheels Manufacturing insert lacks the Praxis patented collet system. Instead, the Wheels Mfg. insert simply clamps against the outside of the bike frame’s bottom bracket shell. The clamping tension, coupled with the tight fit into the frame, holds the insert and the bearings securely.
Unlike Praxis, the offerings from Wheels Manufacturing cover cranksets with 30mm axles as well as 24mm. You also have a choice of bearings: ABEC-3 steel bearings, angular contact bearings, and ZERO hybrid ceramic bearings, all from Enduro. Wheels also offers a conversion for Cervelo’s BBRight bottom brackets available with ABEC-3 and angular contact bearings, which we appreciate very much as a Cervelo dealer.
Enduro TorqTite Bottom Brackets
In addition to making bearings used by others, Enduro has introduced their own line of bottom brackets with a design similar to those of Wheels Manufacturing. As with the Wheels inserts, the Enduro comes in two parts that thread together and squeeze against the outside of the bottom bracket shell, but lacking the Praxis collet design.
The Enduro line is very broad, accommodating a very broad selection of frame designs and cranksets. Enduro makes bearing inserts to fit BB30, PressFit 30, Cervelo BBRight, BB86/92, and even BB386EVO. The bearing inserts are available to fit 24mm Shimano and SRAM GXP cranksets, but also cranksets with 30mm axles. Finally, these inserts are available with either stainless steel angular contact bearings, or ceramic angular contact Enduro bearings. Similar to Wheels Mfg., the Enduro inserts require use of specific installation tools, in this case two Enduro TorqTite wrenches.
BBInfinite makes a one-piece insert that is pressed into the frame, using the retaining fluid that comes with the bottom bracket insert to help hold everything tight. Unlike the other three designs previously discussed, the BBInfinite is not a threaded system, it inserts in one rigid piece that is designed to keep everything in alignment as a unit and is locked into place with gap filling compound (Loctite 609). The BBInfinite system incorporates ABEC-7 steel bearings, the second-highest grade under the ABEC scale, and the tolerances are twice as tight as with an ABEC-3 bearing for smoother operation and increased durability. The BBInfinite is also available with CeramiTech hybrid ceramic bearings, made by BBInfinite. BBInfinite makes inserts for Shimano, SRAM GXP, Campagnolo Ultra Torque, as well as 30mm axle cranksets, to fit bikes with BB30, PressFit 30, Cervelo BBRight, BB86/92, BB386EVO, and Specialized OSBB.
All of these inserts do a really good job of addressing creak in BB30/PressFit frames. We have also installed many of these as original equipment on bikes we are building. A noisy bike is truly annoying, both to you as the rider and to those with whom you ride. If you have creaks in your bike with a BB30-type design, we have more solutions than ever available. Contact us or stop in to discuss which option will work best for you and your bike.