Shimano Abbreviations

Ever wonder what those cryptic names are in Shimano's product model names. Decode them with the following. The first two letters denote:
  • BB - Bottom bracket
  • BC - Brake cable
  • BCC - Battery cable
  • BCR - Battery charger
  • BH - Disc brake hose
  • BL - Brake lever
  • BM - battery mount
  • BR - Brake caliper
  • BTC - Battery case
  • BTH - Battery holder
  • BTR - Battery
  • CB - Coaster brake
  • CD - Chain device
  • CG - Chain guard
  • CJ - Cassette joint
  • CN - Chain
  • CP - Spoke protector
  • CR - Chainring
  • CS - Cassette sprocket
  • CT - Chain tensioner
  • DH - Hub dynamo
  • DU - Drive unit
  • EC - Battery charger
  • EW - Electric wire
  • EWC - Cord cover
  • EWEX - DI2 adapter
  • EWW - Wireless unit
  • FC - Front chainwheel Crank Arm
  • FD - Front derailleur
  • FH - Freehub
  • GM - Grommet
  • HB - Front hub
  • HP - Head parts
  • HRB - Hub roller brake
  • I-SPEC - Integration mounting system of brake and shifting lever
  • ID - CI-DECK
  • JC - Junction
  • LP - Light
  • MF - Multiple freewheel
  • MU - Motor unit
  • O.L.D. - Over Locknut Dimension
  • OT - Outer casing
  • P.C.D. - Pitch Circle Diameter
  • PCE - PC Linkage device
  • PD - Pedal
  • PM - Power modulator
  • QR - Quick release
  • RD - Rear derailleur
  • RT - Disc brake rotor
  • RTAD - Disc brake rotor adapter
  • SB - REVOSHIFT shifter integrated with brake lever
  • SC - Cycle computer System information display
  • SF - Single freewheel
  • SG - Internal geared hub
  • SL - Shifting lever
  • SPD - Shimano pedaling dynamics
  • SPD-SL - Shimano pedaling dynamics-SL
  • ST - Dual control lever/shifting lever integrated with brake lever
  • SW - Switch unit
  • WH - Wheel


Shimano Technologies Explained


HG Sprockets


The distinctively designed HYPERGLIDE sprockets incorporate specially positioned shift ramps and tooth profiles for improved chain control during shifting. Fast and responsive indexed shifting is the result.
The HG cassette sprocket, which was developed for the MTB 10-speed system, underwent comprehensive optimization to achieve super-highly efficient shifting.


HG sprockets

Guide the chain quickly and directly to the next sprocket without override.


Conventional sprockets

Cause the chain to ride up and over the gear teeth before engaging the sprocket.

Press-Fit BOTTOM Bracket


To meet customer needs in the best possible way, SHIMANO has developed the press-fit bottom bracket, staying focused on our final goal: total performance in pedaling.
The bottom bracket axle is steadily supported by the wide placed bearings on the basis of HOLLOWTECH II technologies providing highly-efficient power transfer.


SM-BB94-41A (MTB)
SM-BB92-41B (Road)

Press Fit Bottom Bracket



Providing the best balance of stiffness, strength, weight and rotating performance
The concept of HOLLOWTECH II technology is focused on producing a superior crankset which will maximize a rider’s power transfer. The rigidity of the crankset ensures pedaling efficiency while its weight, a key element of the crankset, you want light, aids in cycling longer distances over which the rider needs to pedal more. Naturally, SHIMANO strove for the optimum balance between the conflicting needs of stiffness while producing a lightweight crank. HOLLOWTECH technology is an ultra-lightweight hollow crankarm created by SHIMANO with the company’s own proprietary forging technology that also maintains rigidity. The addition of HOLLOWTECH II technology integrates the bottom bracket axle with the right crankarm for more stiffness and a weight savings to achieve a high-dimensional balance. Its outboard bottom bracket bearing system provides better weight distribution and more pedaling stability, allowing for more efficient power transfer.
The HOLLOWTECH II crankset has been developed by pursuing the optimum balance of stiffness & rotating performance in a lightweight and beautiful crankset design.
High Precision Sealing
Moreover, HOLLOWTECH II crankset has a high-precision sealing in the bearing area to increase durability maintaining the excellent rotating performance for long periods.


Hollow Tech 2-1


24mm Diameter Axle And Bearings

Why choose the 24mm axle and bearings for the HOLLOWTECH II crankset?

The diameter of the Bottom Bracket axle and bearings was of primary importance for the development because the Bottom Bracket axle area is tied to such key elements as stiffness, strength, weight and rotating performance.

Hollow Tech 2-2

What’s important is the total balance of crankset

In addition, taking the crankset as a whole, the total balance of crankarm rigidity, axle stiffness, bearing position and others is essential.

Indeed, the crankset is designed by careful consideration of the total balance of those elements to prevent breakage.

Outboard Bearing

For most frames with 68mm Bottom Bracket shells, HOLLOWTECH II with 24mm axle can set the bearing position outside of the frame to provide better weight distribution and more stability.

Hollow Tech 2-3

Outboard Bearing

For most frames with 68mm Bottom Bracket shells, HOLLOWTECH II with 24mm axle can set the bearing position outside of the frame to provide better weight distribution and more stability.

Hollow Tech 2-4

24mm Diameter Axle And Bearings Provide Optimum Balance For The Crankset

After studying all these problems thoroughly, we made the decision to adopt the 24mm diameter axle and bearings, which have the optimum balance, for the HOLLOWTECH II crankset.

In addition, an examination of the total crankset, including the crankarm and gears, proves the optimum balance of rigidity, weight and rotating performance for the ultimate transfer of power to your bike. HOLLOWTECH II is simply the most optimized crankset design on the market.



The SIS rear index shifting system was adopted at the front. With the index system at the front shifting operation is easier and more comfortable.



SHIMANO’s next generation 10-speed MTB drivetrain
SHIMANO presents the drivetrain technology for mountain bikes: DYNA-SYS. This revolutionary technology uses a 10-speed cassette, but that is not the only feature of this system. Highlight is a completely redesigned drivetrain that creates real added benefits for the rider.
It’s not only an extra gear…
It’s about closer gear ratios for a smoother shifting performance and improved power transfer
It’s about riding optimized gear combinations that improve efficiency and durability
It’s all about performance: DYNA-SYS offers a more stable drivetrain for any type of rider!

Inherently Efficient

A wider-range 11-36T 10-speed HG cassette means riders can spend more time in their Primary Driving Gear—the 32-tooth ring. Traditionally, triple-ring riders have had to get used to making two to three recovery shifts in the back every time they drop into the 22T granny. With DYNA-SYS, it’s just one recovery shift, and it’s needed less often. Shifting is smoother and faster thanks to CloseStep gear ratios—42-32-24. Getting from the 24-tooth ring back into the Primary Driving Gear—the middle ring—is easier and more intuitive. And a more manageable 42-tooth big-ring is also easier to get into, which means riders will use it more. DYNA-SYS technology makes the shifting transitions seamless, enabling riders to deliver consistent, efficient power while maintaining traction and momentum.

When pedaling in steep climbing sections...


Combining wider gear ratios with the CloseStep chainring minimizes cadence change and pedaling loss, making power transfer more efficient.

Remarkably Stable

An asymmetrical mountain bike-specific chain means smoother shifts, lighter weight, and better overall system performance. CloseStep gear ratios mean smaller jumps between gears, more efficient chain movement and a reduced chance of dropping a chain while shifting in rough conditions.

The more efficiently redesigned cable routing and shorter rear derailleur housing helps make the system less prone to contamination, trail chatter or suspension movement. The Compact Cage rear derailleur and a smaller big-ring allow for fewer chain links, which translates to a quieter, more stable transmission. The Long-Arm rear derailleur architecture increases the mechanical advantage for Advanced Light Action shifting.

DYNA-SYS CloseStep gears are based on the 32T middle chainring, helping make overall power transfer more efficient

  • The 32T is the most effective and most often used chainring in off-road riding.
  • DYNA-SYS Technology minimizes the variation in driving chain position relative to most bikes’ effective main pivot, reducing unwanted influence on suspension performance.
Pivot Position



Rhythm and Range
The real advantage of 11-speed is the ability to have all the range you require without sacrificing the rhythm you need.

Wider Driving Range / Total Range Gear Range Comparison


RANGE Optimized Chainwheels

Chainwheels matched with specific sprockets for:

  • Improved gear quality and driving efficiency

    - Reduced cross-chain

    - Effective gear steps

  • Larger diameter, longer wearing cogs

At the range

DRIVING: gears are purpose matched to keep you riding efficiently without front shifting

CLIMBING: gears are chosen to compliment the lowest cogs and maximize seated traction

Driving range

DYNA-SYS11 maximizes rhythm with “rhythm step” gears in the most frequently used range.

  • Less front shifting thanks to optimum front gear teeth
  • Rider controls cadence and energy use by rear close ratio

Climbing range

DYNA-SYS11 maximizes rhythm with “rhythm step” gears in the most frequently used range.

  • Smooth shifting performance thanks to front close gear ratio
  • Rider controls cadence and energy use by rear close ratio

Highly Efficient gear combination

Driving efficiency is a key drivetrain performance indicator.

  • More speed for the same effort
  • Multiple front gear (2x, 3x) maintains higher efficiency in all range

Gear Ratio

M9000 series

Front double 36-26T, Cassette sprocket 11-40T / Front single 30T, Cassette sprocket 11-40T


MEGA 9 DriveTrain


The 9-speed gear cluster actualizes close ratio gearing without impairing wide gear range.



Light pedaling with efficient drivetrain
Optimal gear ratio for each wheel size
The larger the wheel the more range needed in the cassette to maintain light pedaling.

Refined front shifting system
Gear combinations specialized for each tire size reduces the number of recovery rear shifts needed with front close gear ratio.
Tire clearance improved for better maneuverability




Win all kinds of gravity races!
SHIMANO MODULAR CHAIN DEVICE is tough and efficient chain device. Rider can choose one half guard/two half guards/no guard according to course/usage. It has minimum bash guard for protecting chain and chain ring from impact. And replaceable silencer works less noise, easy focus on your riding. Moreover SHIMANO MODULAR CHAIN DEVICE ensures super stable and silent drivetrain with SHIMANO SHADOW RD+ rear derailleur.

*Courtesy: Shimano Japan.