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Shimano BB-UN300 MTB bottom bracket, square spindle 122.5mm - EBBUN300B22X
Voir les avis clients(2 reviews)
square spindle, 122.5mm in length
Notre avis
Need to replace your Shimano bottom bracket? This model is suitable for a generation of cranksets with a square axle. The length of this model is 122.5 mm.
Sylvain C.
Mechanical expert
Are you looking for a Shimano mountain bike bottom bracket with a square taper spindle to replace your old model? The Shimano BB-UN300 EBBUN300B22X is a suitable solution for bikes fitted with a crankset compatible with a JIS square taper spindle.
Developed by Shimano, the BB-UN300 is a cartridge bottom bracket fitted with bearings designed to provide a smooth pedalling experience and reliable performance for everyday use. Shimano also states that this range features a stabiliser designed to maintain a consistent chainline.
This specific version has a 122.5 mm square axle and is designed for a 68 mm-wide bottom bracket shell with a BSA 1.37 x 24 thread. The manufacturer’s part number is EBBUN300B22X and its EAN code is 4550170619152.
The BB-UN300 Shimano e is particularly suitable for mountain bikes, hybrid bikes and city bikes that still use a square-taper crankset. It offers a practical alternative for refurbishing a bike fitted with an older generation drivetrain without having to replace the entire crankset.
Key features of the BB-UN300 122.5 mm Shimano
- JIS square spindle compatible with cranksets designed for this standard.
- Axle length: 122.5 mm.
- Bottom bracket shell: 68 mm.
- BSA thread: 1.37 x 24.
- Cartridge design with integrated bearings.
- Aluminium adaptors and steel axle.
- Shimano stabiliser to maintain a consistent chainline.
- Ideal solution for replacing a worn bottom bracket.
- Shimano part number: EBBUN300B22X.
Compatibility: check the axle length
The length of 122.5 mm is a crucial factor to check before purchasing. A square-axle bottom bracket is not automatically compatible with all square-axle cranksets: the axle length plays a key role in determining the crankset’s positioning and chainline.
To replace your old bottom bracket, you should therefore check the width of the bottom bracket shell, the type of threading, the mounting standard and the axle length. For this part number, EBBUN300B22X, the configuration corresponds to a 68 mm BSA bottom bracket with a 122.5 mm square spindle.
Technical specifications
| Feature | Details |
|---|---|
| Brand | Shimano |
| Model | BB-UN300 |
| Part number | EBBUN300B22X |
| Type | Cartridge bottom bracket |
| Crank interface | JIS square spindle |
| Axle length | 122.5 mm |
| Bottom bracket width | 68 mm |
| Thread | BSA 1.37 x 24 |
| Axle | Steel |
| Adapters | Aluminium |
| Use | Mountain bikes, hybrid bikes, city bikes |
| EAN | 4550170619152 |
Frequently asked questions
Want to find out more?
La référence EBBUN300B22X correspond à une boîte de pédalier de 68 mm. Shimano propose également le BB-UN300 dans d’autres configurations, notamment pour des boîtes de 73 mm. Il est donc important de ne pas confondre les différentes références.
Le BB-UN300 EBBUN300B22X utilise un filetage BSA 1.37 x 24, également appelé filetage anglais.
Oui. Le BB-UN300 est notamment destiné aux applications VTT, VTC et vélo de ville équipées d’un pédalier à axe carré compatible.
Oui. Le Shimano BB-UN300 utilise une conception à cartouche avec roulements intégrés, ce qui simplifie le remplacement du boîtier de pédalier.
Non, pas nécessairement. Si votre pédalier à axe carré est en bon état et compatible avec un axe de 122,5 mm, vous pouvez simplement remplacer le boîtier de pédalier.
Le remplacement nécessite notamment un outil adapté au démontage et au montage du boîtier de pédalier ainsi que les outils nécessaires au retrait du pédalier. Shimano référence notamment l’outil TL-UN74 pour les boîtiers de cette famille.
Relevez les dimensions de votre boîtier actuel : largeur de la boîte, filetage, type d’axe et longueur de l’axe. Pour le EBBUN300B22X, la configuration à rechercher est BSA 68 mm + axe carré 122,5 mm.
Le Shimano BB-UN300 axe carré 122,5 mm est une solution simple pour remplacer un boîtier de pédalier usé sur un vélo équipé d’un pédalier traditionnel. Sa conception à cartouche, son axe carré JIS et sa fabrication Shimano en font une pièce adaptée à de nombreuses configurations de VTT et vélos de loisir.
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