Modified at: Jul 20, 2023
Posted at: Nov 28, 2021
In-depth comparison of Shimano Hollowtech 2 and BB (bottom bracket) units! A comparison of the specs of the different BBs in terms of weight and compatibility. The following is a summary of the points to consider when selecting a BB.
Table of contents
Sponsored Link
Hollowtech 2 BBs for road bikes are available in three types of screw-in type and two types of press-fit type in the current model lineup.
SHIMANO BB-R9100
| Manufacturer | Shimano |
|---|---|
| Standard | Hollowtech 2 |
| Brand | DURA-ACE |
| Weight | 65g |
| BB Shell Width | 68mm、70mm |
| Joining method | Threaded |
SHIMANO SM-BB72-41
| Manufacturer | Shimano |
|---|---|
| Standard | Hollowtech 2 |
| Brand | ULTEGRA/105 |
| Weight | 69g |
| BB Shell Width | 86.5mm |
| Joining method | Press-fit |
SHIMANO SM-BBR60
| Manufacturer | Shimano |
|---|---|
| Standard | Hollowtech 2 |
| Brand | ULTEGRA/105 |
| Weight | 77g |
| BB Shell Width | 68mm、70mm |
| Joining method | Threaded |
SHIMANO BB-RS500
| Manufacturer | Shimano |
|---|---|
| Standard | Hollowtech 2 |
| Brand | TIAGRA |
| Weight | 92g |
| BB Shell Width | 68mm、70mm |
| Joining method | Threaded |
SHIMANO BB-RS500-PB
| Manufacturer | Shimano |
|---|---|
| Standard | Hollowtech 2 |
| Brand | GRX |
| Weight | 70.4g |
| BB Shell Width | 86.5mm |
| Joining method | Press-fit |
The Hollowtech 2 BB for MTB is available in three screw-in types in the current model lineup. There are no press-fit BBs.
SHIMANO SM-BB93
| Manufacturer | Shimano |
|---|---|
| Standard | Hollowtech 2 |
| Brand | XTR |
| Weight | 73g |
| BB Shell Width | 68mm、73mm |
| Joining method | Threaded |
SHIMANO SM-BB80
| Manufacturer | Shimano |
|---|---|
| Standard | Hollowtech 2 |
| Brand | SAINT |
| Weight | 95g |
| BB Shell Width | 68mm、73mm、83mm |
| Joining method | Threaded |
SHIMANO BB-MT801
| Manufacturer | Shimano |
|---|---|
| Standard | Hollowtech 2 |
| Brand | DEORE XT |
| Weight | 84g |
| BB Shell Width | 68mm、73mm |
| Joining method | Threaded |
SHIMANO BB-MT800
| Manufacturer | Shimano |
|---|---|
| Standard | Hollowtech 2 |
| Brand | DEORE XT |
| Weight | 82g |
| BB Shell Width | 68mm、73mm |
| Joining method | Threaded |
SHIMANO SM-BB52
| Manufacturer | Shimano |
|---|---|
| Standard | Hollowtech 2 |
| Brand | - |
| Weight | - |
| BB Shell Width | 68mm、73mm |
| Joining method | Threaded |
Sponsored Link
Here is a comparison of the Shimano Hollowtech 2 BBs introduced so far in terms of grade, weight, system, and compatible shell width.
| Products | Brand | Weights | Joining method | Supported Shell Widths |
|---|---|---|---|---|
| BB-R9100 | DURA-ACE | 65g | Threaded | 68mm、70mm |
| SM-BBR60 | ULTEGRA/105 | 77g | Threaded | 68mm、70mm |
| BB-RS500 | TIAGRA | 92g | Threaded | 68mm、70mm |
| SM-BB93 | XTR | 73g | Threaded | 68mm、73mm |
| SM-BB80 | SAINT | 95g | Threaded | 68mm、73mm、83mm |
| BB-MT800 | DEORE XT | 95g | Threaded | 68mm、73mm |
| SM-BB52 | - | - | Threaded | 68mm、73mm |
In terms of weight, it does not make much difference which grade you choose, as it is light enough to be under the 70g range.
On the other hand, shell widths are available in a variety of widths, so there is a good chance that one of the models will fit your frame.
| Products | Brand | Weights | Joining method | Supported Shell Widths |
|---|---|---|---|---|
| SM-BB72-41 | ULTEGRA/105 | 69g | Press-fit | 86.5mm |
| BB-RS500-PB | GRX | 70.4g | Press-fit | 86.5mm |
There are only two options for press-fit BBs in the current models, and both have almost identical specs. The GRX, which is a gravel component, is built for dirt, so you can choose the BB-RS500-PB for gravel or the SM-BB72-41 for road.
Shimano Hollowtech 2 BBs are divided into two types: screw-in and press-fit. There are many screw-in BBs available, but there are only two press-fit BBs available from the current model lineup.
Next, you can narrow down your selection by the width of the BB shell. Shimano Hollowtech 2 BBs are available in five different widths: 68mm, 70mm, 73mm, 83mm, and 86.5mm, so choose the one that matches the width of your frame.
At this point, your choices will be quite limited.
Once you’ve narrowed down your search by “mounting standard,” the last thing to consider is weight, color, and grade.
Most of the Shimano Hollowtech 2 BBs are lightweight models to begin with, so there is not much of a weight difference.
Also, Shimano Hollowtech 2 BBs are not available in many colors, so you can choose the color you want to match your frame.
Lastly, the grade of Shimano Hollowtech 2 BBs is generally said that there is not much difference in performance between the different grades.
Summary of special tools required for installation and maintenance of the Shimano Hollowtech 2
Hollowtech 2" is the standard adopted by the latest Shimano front cranks. We have compiled a list of special tools required for installation and maintenance of "Hollowtech 2", which is unavoidable when upgrading to higher grade front cranks.
| Manufacturer | Shimano |
|---|---|
| Standard | Hollowtech 2 |
| Brand | DURA-ACE |
| Weight | 65g |
| BB Shell Width | 68mm、70mm |
| Joining method | Threaded |
| Manufacturer | Shimano |
|---|---|
| Standard | Hollowtech 2 |
| Brand | ULTEGRA/105 |
| Weight | 69g |
| BB Shell Width | 86.5mm |
| Joining method | Press-fit |
| Manufacturer | Shimano |
|---|---|
| Standard | Hollowtech 2 |
| Brand | ULTEGRA/105 |
| Weight | 77g |
| BB Shell Width | 68mm、70mm |
| Joining method | Threaded |
| Manufacturer | Shimano |
|---|---|
| Standard | Hollowtech 2 |
| Brand | TIAGRA |
| Weight | 92g |
| BB Shell Width | 68mm、70mm |
| Joining method | Threaded |
| Manufacturer | Shimano |
|---|---|
| Standard | Hollowtech 2 |
| Brand | GRX |
| Weight | 70.4g |
| BB Shell Width | 86.5mm |
| Joining method | Press-fit |
| Manufacturer | Shimano |
|---|---|
| Standard | Hollowtech 2 |
| Brand | XTR |
| Weight | 73g |
| BB Shell Width | 68mm、73mm |
| Joining method | Threaded |
| Manufacturer | Shimano |
|---|---|
| Standard | Hollowtech 2 |
| Brand | SAINT |
| Weight | 95g |
| BB Shell Width | 68mm、73mm、83mm |
| Joining method | Threaded |
| Manufacturer | Shimano |
|---|---|
| Standard | Hollowtech 2 |
| Brand | DEORE XT |
| Weight | 84g |
| BB Shell Width | 68mm、73mm |
| Joining method | Threaded |
| Manufacturer | Shimano |
|---|---|
| Standard | Hollowtech 2 |
| Brand | DEORE XT |
| Weight | 82g |
| BB Shell Width | 68mm、73mm |
| Joining method | Threaded |
| Manufacturer | Shimano |
|---|---|
| Standard | Hollowtech 2 |
| Brand | - |
| Weight | - |
| BB Shell Width | 68mm、73mm |
| Joining method | Threaded |
Sponsored Link
Features of TPU tubing and advantages and disadvantages of using it on road bikes and MTB
TPU tubes are gaining attention as the third force in bicycle tires. We summarize its features, advantages and disadvantages of using it on road bikes and MTBs, and major manufacturers.
Summary of Shimano mechanical brake levers for MTB and cross bike
Shimano mechanical brake levers are now few and far between. The following is a summary of the current model lineup, specifications, and compatible components.
Summary of electric components for MTB
This section summarizes the types of electric components for MTB and the advantages and disadvantages of each.
Types of MTB dropper seatposts from major manufacturers and points to consider when choosing one
The dropper seat post is becoming a "must-have" part for MTB. Here we summarize the lineup, specifications, and features of dropper seatposts for MTB from major manufacturers, as well as a comparison of each manufacturer and points to consider when choosing a dropper seatpost.
SRAM Component Grades and Compatibility Summary for MTB
This section summarizes the grades, features, and compatibility of SRAM's Eagle series of components for MTB, as well as the electric component AXS and the latest component, Eagle Transmission.
SRAM's MTB sprockets and compatibility, summary of points to consider when choosing
SRAM components are being increasingly adopted in entry-grade MTB. In this issue, we summarize SRAM's sprockets for MTB and points to consider when choosing one.
MTB suspension fork interchangeability standard! You definitely want to check when replacing.
When it comes to serious MTB customization, suspension fork upgrades are the way to go. However, there are various standards for MTB suspension forks, and if you choose the wrong one, it may not work at all.
Summary of 12-speed sprockets for MTB that can be used with Shimano Free (HG spline)
We have put together a 12-speed sprocket that is not part of Shimano's 12-speed lineup for MTB. With this one, it is possible to convert to 12-speed with a conventional Shimano free (HG spline) without upgrading the wheels.
Shimano MTB sprocket and wheel (free body) compatibility summary
This section summarizes the compatibility of Shimano's sprockets and wheels (free bodies) for MTB, which are a mixture of old and new standards, the latest Micro Spline and the previous HG spline, and what to look out for when purchasing.
End width? Boost? MTB end standards and what to look out for when buying an MTB.
Detailed explanation of MTB end standards! What is the boost standard? What is the end width that fits your MTB, points to keep in mind when buying an MTB, etc.
MTB wheel standards and how to choose one without fail.
The following is an overview of MTB wheel standards, their compatibility, and how to choose the right wheel for you.
What is a Tire Insert? Advantages and Disadvantages
This section summarizes what tire inserts are and the advantages and disadvantages of using them, which have been attracting attention along with the spread of tubeless tires and have recently been used in professional road racing.
Summary of Shimano disc brake pad types and compatibility
This section summarizes the types of Shimano disc brake pads, the differences between models, and compatible brake calipers.
TPI, Compound, Tread? Understanding Bicycle Tire Specifications
When looking for items to upgrade your road, MTB, or gravel bike tires, technical terms such as TPI, compound, and pattern appear in the descriptions. At first glance, tire specifications may seem difficult to understand, but if you keep only the important details in mind, your tire selection will be enhanced.
What is a torque wrench? Advantages and disadvantages of torque management
A torque wrench is a useful tool to have if you want to properly maintain your road bike or MTB. The following is a summary of what a torque wrench is and the advantages and disadvantages of torque management.
The bead won't come up! How to raise the bead on tubeless tires
Bead raising" is an essential task with tubeless tires. However, there are times when it is easy to raise the bead, and other times when it does not raise at all despite your best efforts. In this issue, we will introduce a method to raise the bead of a tubeless tire that will not raise, considering the cause.
What is bicycle disc rotor distortion? What causes it and how to correct the distortion
If you hear a strange "shuffling" noise coming from the disc rotor area of your disc brake bicycle, it could be disc rotor distortion. This section summarizes why disc rotor distortion occurs and how to correct the distortion.
Tubeless is reassuring to have! Summary of air pumps with booster/boost function
The booster simplifies bead raising, which is the most difficult part of tubeless installation. We have compiled a list of air pumps with booster(boost functions) that are reassuring to have one.
What is hookless rim? Advantages, Disadvantages and Points to Consider When Choosing
Many "hookless rim" wheels are lightweight and cost-effective. What is hookless? We have compiled a list of advantages and disadvantages of hookless, as well as points to keep in mind when choosing.
What is the ASTM standard for bicycle wheels?
What is the ASTM standard for bicycle wheels? We have compiled a list of points to note when choosing a wheel.