1. Киришүү
The Praxis BB M30 Road 68 mm BB30/PF30 Bottom Bracket is a high-quality component designed to provide a smooth and reliable interface between your bicycle's crankset and frame. This bottom bracket is specifically engineered for BB30 and PF30 frame standards, accommodating frame diameters of 42mm or 46mm and widths of 68mm, 73mm, or 61.5mm (for Specialized OSBB). It is compatible with Praxis M30 30-28mm cranksets.
This manual will guide you through the proper installation, operational understanding, maintenance, and troubleshooting of your Praxis bottom bracket to ensure its optimal performance and longevity.

Figure 1: Praxis BB M30 Road 68 mm BB30/PF30 Bottom Bracket, showing its robust construction and integrated bearings.
2. Орнотуу жана орнотуу
2.1. Шайкештикти текшерүү
Before installation, it is crucial to confirm that your bicycle frame and crankset are compatible with the Praxis BB M30 bottom bracket. This bottom bracket is designed for:
- Frame Standards: BB30 and PF30.
- Frame Internal Diameter: 42мм же 46мм.
- Frame Shell Width: 68mm, 73mm, or 61.5mm (Specialized OSBB).
- Crankset Compatibility: Praxis M30 30-28mm cranksets only. This bottom bracket is not compatible with other 30mm systems.
For detailed frame compatibility, refer to the general bottom bracket compatibility chart below. It is highly recommended to dismantle your original bottom bracket to accurately measure your frame's internal diameter and width.

2-сүрөт: Каптал view of the Praxis BB M30 Bottom Bracket, highlighting the precision-machined cups and internal structure.
2.2. General Bottom Bracket Compatibility Chart
| Ички диаметри | Box Width | Ассамблеянын түрү | Стандарт | Recommended BB |
|---|---|---|---|---|
| 34.8 мм | 68 мм | жиптүү | BSA / BSC | 24 mm / GXP / Dub 29 mm |
| 36 мм | 70 мм | жиптүү | Итальянча | 24 мм |
| 37 мм | 90.5 мм | Press-Fit | BB 90 (Trekking) | 24 mm / GXP / Dub 29 mm |
| 41 мм | 86.5 мм | Press-Fit | PF 86 (Shimano) | 24mm / GXP / Dub 29 mm |
| 41 мм | 89.5 мм | Press-Fit | PF 90 (Shimano) | 24mm / GXP / Dub 29 mm |
| 42 мм | 68 мм | Press-Fit | BB 30 | 30 mm / Dub 29 mm |
| 42 мм | 79 мм | Press-Fit | BB Right | 30 mm / Dub 29 mm |
| 46 мм | 61 мм | Press-Fit | Адистештирилген | 30mm / Dub 29 mm |
| 46 мм | 68 мм | Press-Fit | PF 30 | 30 mm / Dub 29 mm |
| 46 мм | 79 мм | Press-Fit | BB Right PF | 30 mm / Dub 29 mm |
| 46 мм | 86.5 мм | Press-Fit | 386 EVO | 30mm / Dub 29 mm |
Note: The Praxis BB M30 is a press-fit bottom bracket. Ensure your frame is compatible with press-fit installation.

Figure 3: Included spacers and washers for the Praxis BB M30 Bottom Bracket, essential for proper crankset alignment and bearing preload.
2.3. Орнотуу кадамдары (Жалпы көрсөтмө)
Installation of a press-fit bottom bracket requires specific tools and mechanical aptitude. If you are unsure about any step, it is highly recommended to seek assistance from a professional bicycle mechanic.
- кадрды даярдоо: Ensure the bottom bracket shell of your frame is clean, free of debris, and properly faced (if necessary) to ensure a flush fit.
- Майды колдонуу: Apply a thin layer of high-quality bicycle grease to the inside of the bottom bracket shell and the outer surfaces of the bottom bracket cups.
- Press the Cups: Using a dedicated bottom bracket press tool, carefully press each cup into the frame's bottom bracket shell. Ensure they are pressed in straight and evenly. Do not use a hammer or other impact tools.
- Install Crankset: Follow the instructions provided with your Praxis M30 crankset for proper installation, including any necessary spacers or wave washers.
- Моменттин мүнөздөмөлөрү: Adhere strictly to the torque specifications provided by Praxis for both the bottom bracket and crankset components. Overtightening or undertightening can lead to damage or premature wear.
For detailed, step-by-step installation instructions, please refer to the official PDF documentation available on the Praxis Works website, which may be linked from the product page where you purchased this item.
3. Иштөө принциптери
The bottom bracket serves as the central rotating component of your bicycle's drivetrain, allowing the crankset to spin freely and efficiently. The Praxis BB M30 utilizes durable steel cartridge bearings housed within precision-machined 7075 T6 aluminum cups. This design ensures smooth power transfer from your pedals to the rear wheel, minimizing friction and maximizing pedaling efficiency.
Proper installation and maintenance are key to ensuring the bottom bracket operates silently and without resistance, providing a fluid pedaling experience.
4. Техникалык тейлөө
Regular maintenance is essential for the longevity and performance of your Praxis bottom bracket. While the sealed cartridge bearings are designed for durability, periodic checks can prevent issues.
- Тазалоо: Keep the area around the bottom bracket shell clean from dirt, grit, and road grime. A build-up of contaminants can lead to premature wear of seals and bearings.
- Inspection for Play: Periodically check for any lateral play in the crankset. If you detect movement, it may indicate loose crank bolts, worn bearings, or an improperly installed bottom bracket.
- Майлоо: The sealed bearings do not require external lubrication. However, ensure that the crank spindle and any interfaces with the bottom bracket are lightly greased during installation to prevent creaking and facilitate future removal.
- Подшипник алмаштыруу: Like all wear components, the bearings will eventually wear out. If the bottom bracket feels rough, gritty, or develops significant play, it's time for replacement. The Praxis BB M30 is designed for easy replacement of the entire unit.
5. Жалпы көйгөйлөрдү чечүү
If you experience issues with your bottom bracket, consider the following common problems and their potential solutions:
- Creaking Noise:
- Себеби: Often caused by insufficient grease during installation, loose crank bolts, or contamination.
- Чечим: Remove the crankset and bottom bracket, clean all surfaces thoroughly, reapply appropriate grease, and reinstall ensuring all components are torqued to specification. If creaking persists, bearings may be worn.
- Loss of Fluidity / Roughness:
- Себеби: Worn or contaminated bearings.
- Чечим: This indicates the bearings have reached the end of their lifespan. The entire bottom bracket unit should be replaced.
- Play in Crankset:
- Себеби: Loose crank bolts, worn bearings, or incorrect spacing/preload.
- Чечим: First, check and re-torque crank bolts. If play persists, inspect the bottom bracket for wear or ensure all spacers and wave washers are correctly installed according to your crankset's instructions. If bearings are worn, replacement is necessary.
6. Техникалык шарттар
| Өзгөчөлүк | Деталь |
|---|---|
| Бренд | Praxis |
| Модел | BB M30 Road 68 mm BB30/PF30 |
| Бөлүмдүн номери | 854053003880 |
| Материал | 7075 T6 AL Forged and Heat Machined Cups, Steel Cartridge Bearings |
| Түс | Кара |
| Салмагы | 80 грамм |
| Кадрлардын шайкештиги | BB30, PF30 (42mm/46mm ID, 68mm/73mm/61.5mm width) |
| Crankset Compatibility | Praxis M30 30-28mm cranksets only |
| Элементтин пакетинин өлчөмдөрү | 0.04 x 0.04 x 0.04 дюйм |
| Пакет Салмагы | 0.22 фунт |
| Дата биринчи жеткиликтүү | 20-март, 2018-жыл |
7. Кепилдик жана колдоо
For information regarding the warranty of your Praxis BB M30 Bottom Bracket, please refer to the official Praxis Works website or contact their customer support directly. Warranty terms typically cover manufacturing defects and material flaws for a specified period from the date of purchase.
For technical support, additional resources, or to find authorized service centers, visit the official Praxis Works website. Always ensure you are using genuine Praxis replacement parts if any are needed.





