Shimano square taper bottom bracket BB-UN300, superb value for money for BSA bottom bracket.
This bottom bracket will give you value for money in good senses – durable and trusted for rugged operations from India to the US; bike makers love this for the price and durability. Shimano launched the BB-UN300 square taper bottom bracket as the successor of the BB-UN26 and BB-UN55. It covers various applications, from Touring and City bikes to older Road and Mountain bikes. BB-UN300 is available with BSA thread and in different axle lengths. In this type, the bottom bracket axle and crank are connected by a square taper, and the delivery does not include crank bolts.
BB-UN300
SHIMANO – Square Type Bottom Bracket – MTB – Standard Structure
Square Type Bottom Bracket
- SHIMANO quality/performance cartridge bearing square bottom bracket
- Better chain line stability with chain line stabilizer
- 3 structures available
- Standard, E-type, chaincase options
- Adapter Material: Aluminum
Specifications:
- Application: City, Touring, Road, All Mountain, Cross Country
- Type: BSA
- Shell Width: 68 mm
- Axle Length: 110 mm, 113 mm, 117.5 mm, 122.5 mm
- Axle Type: square taper (JIS)
- E-Type Compatibility: some models (Denoted by “E” in the model name)
- Chaincase Compatibility: some models (Denoted by “K” in the model name)
Technical Information:
- Bearings: Steel
- Axle Material: Steel
- Bottom Bracket Cup Material: aluminum (left), aluminum/steel (right)
Compatibility:
- For all cranks with JIS square mount
- FC-M311, FC-M315, FC-M351, FC-M361, FC-M371, FC-M430
- FC-M2000, FC-M3000
- FC-T3010
- FC-MT100
- FC-RS200
- FC-TY301, FC-TY501, FC-TY701
- FC-TX801
- FC-A070, FC-A073
Product Specifications
- MODEL NO: BB-UN300
- SERIES: TOURNEY TX800 Series
- Remarks: * w/ Crank arm fixing bolts spec. Only ** w/ Crank arm fixing bolts spec. is available
- Structure_Standard: ✔
- Axle length/shell width (mm)_107_68 (BC1.37): ✔
- Axle length/shell width (mm)_LL113_73 (BC1.37): ✔
- Axle length/shell width (mm)_D-H_68 (BC1.37): X *
- Axle length/shell width (mm)_117.5_68 (BC1.37): X **
- Axle length/shell width (mm)_XL118_68 (BC1.37): X **
- Axle length/shell width (mm)_XL118_73 mm: ✔
- Axle length/shell width (mm)_D-NL 122_68 (BC1.37): X **
- Axle length/shell width (mm)_D-NL 122_73 (BC1.37): X *
- Axle length/shell width (mm)_D-EL 127_68 (BC1.37): X *
- Axle length/shell width (mm)_LL123_68 (BC1.37): ✔
- Axle length/shell width (mm)_LL123_73 (BC1.37): ✔
- Axle length/shell width (mm)_LL113_68 (BC1.37): X **
- Axle length/shell width (mm)_MM110_68 (BC1.37): X **
- Spindle_Square type: ✔

ENDURO 6707 2RS - ABEC-3 Radial Bearing for Internal Headset - 35mm x 40mm x 5mm
CONTROLTECH ONE GRAVEL HANDLEBAR
CICLOVATION ADVANCED BAR TAPE LEATHER TOUCH, FUSION BLACK
CONTROLTECH Bull Horn Alloy W400 Red
MDH PEDAL PCA-02
Controltech OE Series Stem (Black)
CubiCubi 1200, W/ Aluminum Handelbar Mount
Shimano Ultegra Hydraulic Disc Brake Caliper - BR-R8070( Select Option=RIGHT/REAR, RESIN(W/FIN))
KRUTIALS PLATFORM PEDAL BLACK
3/16 STEEL BALLS GRADE 40 ( PACK OF 1200 )
SHIMANO MTB OTHERS BOTTOM BRACKET , BB - UN300, ( SELECT OPTION = BSA 73MM , 122.5MM(LL123), W/O FIXING BOLT )
SHIMANO GRX HYDRAULIC DISC BRAKE BR-RX810, REAR, FLAT MOUNT, W/ FIXING BOLT FOR MOUNT THICKNESS 25MM ,W/O ADAPTER, W/L03A RESIN PAD(W/FIN)
SHIMANO RESIN PAD W/O FIN(B05S-RX), PAD SPRING, W/3 TYPES OF SPLIT PIN, 1 PAIR
SHIMANO HYDRAULIC DISC BRAKE, BR-RX400, GRX, FRONT, FLAT MOUNT, W/BRACKET FOR 140/160MM ROTOR(ASSEMBLED FOR 160),W/L03A RESIN PAD(W/FIN),IND.PACK
ENDURO BKCJ-0340 - 11 tooth, XD-15 Ceramic Hybrid Bearing, Machined Delrin Derailleur Pulleys for 11 speed Shimano Dura Ace (9000 Series) and Ultegra (8000 Series) Derailleurs (5mm bolt hole) - Red
CICLOVATION ADVANCED BAR TAPE LEATHER TOUCH, DIAMOND BLACK
CICLOVATION ADVANCED BAR TAPE LEATHER TOUCH, 2D CARBON BLACK
Argon 18 E-117 Tri Disc Ultegra Di2 - Blue
SHIMANO HYDRAULIC DISC BRAKE, BR-R7070, 105, FRONT, FLAT MOUNT, W/BRACKET FOR 140/160MM ROTOR(ASSEMBLED FOR 140),W/L03A RESIN PAD(W/FIN),SILVER, IND.PACK
Argon 18 Sum Frame Kit, Race Day Red Gloss
Unior Pro Repair Stand with Single Clamp, Manually Adjustable, Without plate
BIKEHAND PROFESSIONAL TOOL KIT
Argon 18 Electron Pro RIO Pursuit Frame Kit, Black Matte/Red Gloss







