Ryden Square-Taper Bottom Bracket – Sealed Cartridge JIS Bottom Bracket
The Ryden Square-Taper Bottom Bracket is a dependable sealed-cartridge bottom bracket for bicycles with JIS square-taper cranksets, combining a hardened steel spindle with protected internal bearings for smooth rotation, reliable crank support, and consistent, low-maintenance drivetrain performance. It fits BSA-threaded 68 mm and 73 mm shells, with five spindle lengths from 110.5 to 127.5 mm, and suits city bikes, hybrids, commuters, touring bicycles, recreational mountain bikes, fitness bikes, and many entry-level road and utility bicycles. Its sealed cartridge helps protect the bearings from road dirt, dust, and moisture, and it’s simpler to replace than a traditional adjustable cup-and-cone bottom bracket.
The width of your frame’s BSA-threaded bottom bracket shell, measured face to face.
Choose the spindle length your crankset specifies: it sets the chainline.
- ✓ Sealed cartridge bearings, no preload adjustment
- ✓ JIS square-taper crank interface
- ✓ BSA / English thread: 1.37" × 24 TPI
- ✓ 68 mm or 73 mm shell; spindles 110.5–127.5 mm
- ✓ Hardened high-strength steel spindle
- ✓ 1×/2×/3× cranksets when matched; crank bolts not included
Proven simplicity. Reliable drivetrain support.
Four tapered flats on each end of the spindle hold the crank arm with one bolt per side: no splines, no external bearings, and very little to set up.
The spindle and bearings form one integrated unit that needs no routine bearing adjustment and helps keep out dirt, dust, and moisture.
High-strength hardened steel resists bending and fatigue for stable, long-term crank support.
Threads into BSA / English 1.37" × 24 TPI frame shells in the two most common widths.
110.5, 113, 118, 122.5, and 127.5 mm, so you can match the spindle length and chainline your single, double, or triple crankset specifies.
Square taper is one of the oldest crank interfaces still in everyday use, and still one of the most common. Four tapered flats on each end of the spindle, one bolt per crank arm, and nothing to adjust: that’s why it is fitted to city, commuter, and utility bicycles all over the world, and why parts for it stay easy to find.
The Ryden Square-Taper Bottom Bracket pairs that interface with sealed cartridge construction, which removes the need for routine bearing adjustment. Instead of separate cups, loose bearings, cones, and axle adjustments, the spindle and its bearings come as one sealed unit.
That makes installation simpler and everyday maintenance significantly easier. When the bearings reach the end of their service life, you replace the complete cartridge.
It suits city, hybrid, commuter, touring, and utility bikes, as well as recreational mountain bikes and traditional road bikes, where simplicity and durability matter more than marginal weight savings.
Sealed cartridge construction
Traditional bottom brackets often used separate bearing cups with loose or caged bearings. Those systems needed periodic adjustment, greasing, bearing inspection, and cup servicing.
The Ryden Square-Taper Bottom Bracket uses a sealed cartridge instead: the spindle and bearings are assembled into one compact, integrated unit. This gives you:
- •Factory-set bearing preload
- •No routine bearing adjustment
- •Better protection from dirt and water
- •Quicker installation
- •Replacement as a single unit
The bearings aren’t serviced on their own. When they reach the end of their service life, the cartridge comes out and a new one goes in, which takes about as long as the first installation.
Hardened steel spindle
The spindle links the two crank arms, so every pedal stroke passes through it on its way to the chainrings. That means it takes repeated:
- •Torsional loads
- •Bending forces
- •Rider weight transfer
- •Pedaling impacts
- •Long-term fatigue cycles
That’s why it’s made from hardened high-strength steel, which resists bending under load, gives good fatigue life, and holds its dimensions through years of riding so the crank arms stay properly supported.
Smooth bearing support
A bearing sits at each end of the cartridge, inside the shell, so the spindle is supported close to both crank arms. Correctly installed, the bottom bracket should turn:
- •Smoothly
- •Quietly
- •Without grinding
- •Without excessive resistance
- •Without noticeable side-to-side movement
The sealed bearings are designed to keep crank rotation smooth in normal commuting and recreational riding. When new, they can feel slightly stiffer by hand than worn or unsealed bearings.
Why square taper still makes sense
Newer crank systems may use hollow spindles, external bearings, integrated axles, press-fit shells, or multi-piece interfaces. Square taper remains extremely practical for many bicycles:
- Broad compatibility
- Square-taper cranksets are available worldwide in countless configurations.
- Affordable replacement
- Replacement cranksets and bottom brackets are generally inexpensive compared with higher-end integrated systems.
- Simple installation
- A bottom bracket tool, a crank puller, and a torque wrench cover the whole job.
- Long service life
- A correctly installed cartridge can give years of everyday service before the bearings need replacing.
- Ideal for utility bicycles
- On commuter, touring, city, rental, and recreational bicycles, simplicity can be worth more than marginal weight savings.
Materials and weight
- Spindle
- Hardened steel.
- Cartridge body
- Steel.
- Cups
- Alloy or reinforced steel, depending on the cup version.
- Bearings
- Sealed cartridge bearings.
- Finish
- Black / silver components.
- Weight
- Approx. 275–335 g, depending on spindle length and cup version; longer spindles generally weigh slightly more.
For commuter and utility riding, durability and bearing protection come before extreme weight reduction.
In the box
- •Sealed cartridge with integrated drive-side threaded cup
- •Non-drive-side retaining cup
- •Installation and compatibility guide
- •Crank bolts aren’t included: use the bolts your crankset specifies
Questions about this product (30)
A (Ryden team): A sealed cartridge bottom bracket with a JIS square-taper crank interface.
What frames will it fit?+
Frames with a BSA / English threaded bottom bracket shell, 68 mm or 73 mm wide.
What thread standard does it use?+
BSA / English, 1.37" × 24 TPI.
What cranksets are compatible?+
Cranksets with a JIS square-taper interface, as long as the spindle length you choose matches the crank manufacturer’s requirement. It doesn’t fit Ryden’s road, MTB, and city/hybrid cranksets, which have an integrated 24 mm spindle and need a 24 mm bottom bracket.
Is this compatible with ISO square-taper cranks?+
No. It’s designed for JIS cranksets, and mixing JIS and ISO parts isn’t recommended because the crank can sit in the wrong position on the spindle.
What spindle lengths are available?+
110.5, 113, 118, 122.5, and 127.5 mm, each for both 68 mm and 73 mm shells.
How do I know which spindle length I need?+
Check the crankset manufacturer’s specification, or match the spindle length of the correctly working bottom bracket already on your bike. A marking such as 68 × 113 means a 68 mm shell and a 113 mm spindle.
Can I just choose the longest spindle to ensure frame clearance?+
No. A spindle that’s too long can give a poor chainline and poor shifting. Choose the length your crankset specifies.
Can I use this with a triple crankset?+
Yes, if the crankset has a JIS square taper and you choose the spindle length the crank specifies.
Can I use it with a single-speed bike?+
Yes, as long as the frame, crankset, chainline, and spindle length all suit it.
Can I use it with a mountain bike?+
Yes, on compatible recreational and traditional MTB setups with a BSA-threaded frame and a JIS square-taper crankset.
Can I use it with a road bike?+
Yes: many traditional and entry-level road cranksets use a JIS square taper. Check the spindle length carefully.
Does it require regular bearing adjustment?+
No. The sealed cartridge doesn’t normally need bearing preload adjustment.
Can the bearings be replaced separately?+
No. It’s designed to be replaced as a complete cartridge when the bearings reach the end of their service life.
Is the spindle hollow?+
No. It uses a conventional hardened, high-strength steel spindle.
What is the difference between 68 mm and 73 mm?+
It’s the width of your frame’s bottom bracket shell, measured face to face. Choose the shell width that matches your frame.
Can I install the 68 mm bottom bracket in a 73 mm frame?+
No. The cups wouldn’t sit correctly in the wider shell and the chainline would be off, so order the width you measured.
Which side is reverse-threaded?+
The drive side. On a standard BSA frame, the drive-side cup has a reverse (left-hand) thread and tightens counterclockwise, viewed from the drive side; the non-drive-side cup tightens clockwise.
How much does it weigh?+
Approx. 275–335 g, depending on the spindle length and the cups.
Is it waterproof?+
No. It’s designed for normal wet-weather riding, with protected bearings, but it isn’t waterproof: don’t submerge it or pressure-wash it directly.
Can I use it on an e-bike?+
Only on e-bikes that keep a conventional threaded bottom bracket and crankset. Most mid-drive systems use their own motor interface, including the Ryden E-Bike Crankset, which fits the motor’s spindle rather than a bottom bracket.
Why does my crank still have side-to-side movement after installation?+
Possible causes are a worn crank interface, incorrect crank installation, loose crank bolts, a damaged bottom bracket, or incompatible components. If the movement remains, have the bike inspected.
Why does my drivetrain chainline look wrong?+
The spindle is probably too short or too long for the crankset. Check the crank manufacturer’s specified spindle length.
Should the spindle spin freely when new?+
It should rotate smoothly, although new sealed bearings can feel slightly stiffer by hand than worn or unsealed bearings.
Can I reuse my existing crank bolts?+
Yes, if they’re compatible, undamaged, and approved for your crankset. Replace damaged or heavily corroded bolts. Crank bolts aren’t included with the bottom bracket.
Can I use this bottom bracket with an external-bearing crankset?+
No. External-bearing cranksets need a different bottom bracket system.
Will it fit a press-fit frame?+
No. It needs a threaded BSA bottom bracket shell.
What does JIS mean?+
Japanese Industrial Standards: the dimensional standard commonly used for modern square-taper bicycle crank interfaces.
How long should a square-taper bottom bracket last?+
It varies a lot with rider weight, weather, mileage, riding style, contamination, and installation quality. A properly installed sealed cartridge can give long service in normal everyday riding.
When should I replace it?+
When it develops persistent play, roughness, or grinding, or when you find bearing failure, spindle damage, or other confirmed structural wear.
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