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.
The BB of DURA-ACE, the top grade for road bikes, is BB-R9100, and it uses small bearings. Although it is a top grade part, some user reviews complain about the reluctance of rotation and durability.
The SM-BB72-41 is a press-fit BB for ULTEGRA/105 grade road bikes, but it cannot be used with threaded BB shells.
The ULTEGRA 105 grade threaded BB for road bikes is the SM-BBR60, which is a popular and standard BB because of its high quality and only 8g difference in weight compared to the higher grade BB-R9100. adaptor (TL-FC25) is required because of the different diameter.
BB-RS500 is a TIAGRA grade screw-in BB for road bikes, which is often installed on 105 and TIAGRA grade complete bikes, and is an entry-level Hollowtech 2 BB. Slightly heavier than higher grade BBs.
BB-RS500B=PB, a GRX grade press-fit BB for gravel roads, slightly heavier than the higher grade SM-BB72-41, but more durable thanks to a new sealing structure.
The Hollowtech 2 BB for MTB is available in three screw-in types in the current model lineup. There are no press-fit BBs.
The SM-BB93 is the top grade XTR screw-in BB for MTB, weighing only 73 grams and compatible with not only 73mm but also 68mm, so it can be installed on road bike frames.
The gold-colored SAINT SM-BB80 threaded BB for MTB is slightly heavier at 95g, and is compatible not only with 73mm but also with 68mm and 83mm.
BB-MT800, DEORE XT’s screw-in BB for MTB. 82g heavier than the top-of-the-line SM-BB93, but other than that, there is not much difference in specifications.
Here is a comparison of the Shimano Hollowtech 2 BBs introduced so far in terms of grade, weight, system, and compatible shell width.
| Products | Grades | Weights | Formulas | 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 | Grades | Weights | Formulas | 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.
Sponsored Link
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.
What to do when you get a flat tire with a tubeless or tubeless ready tire
Tubeless tires have seen a dramatic increase in the number of users over the past few years. Even with tubeless and tubeless ready tires, punctures cannot be reduced to zero. The following is a summary of the causes of punctures and how to deal with them.
How to check compatible tires from wheel specs
When trying to change tire thickness on a road bike or other sport bicycle, it is important to know what tire size the wheel will allow. In this article, we will show you how to find out which tires are compatible with your wheel based on its specifications.
What is a tubeless valve? Types and How to Choose
The tubeless valve is an essential item for tubeless use. What is a tubeless valve, tubeless valve types, and how to select one are summarized below.
What is SRAM's XDR and XD? What is the difference from Shimano?
The following is a summary of SRAM's proprietary XD and XDR standards, what makes them different from Shimano's, and what to look for when purchasing.
Summary of Shimano wide ratio sprockets for road bikes
Shimano wide-ratio sprockets for road bikes are listed here, including compatibility by step number.
Summary of 12-speed chains for use with Shimano road bike and MTB components
We have compiled a list of 12-speed chains that can be used with Shimano road bike and MTB components. Also about chain compatibility with chains from manufacturers other than Shimano.
Types of bicycle disc brake mounts, how to recognize them, and how to choose an adapter.
Mounting adapters for bicycle disc brakes are essential when changing calipers with different standards or rotor sizes. This section explains the types of mount adapters, how to recognize them, and the model numbers of Shimano's mount adapters.
Inside, outside serrations? Types of center lock locking rings
There are two types of lock rings for center locking disc brakes, inner serration and outer serration. The following is a summary of the differences and how to select the right one.
Summary of mechanical disc brake calipers for road use
Mechanical (mechanical) disc brake calipers are ideal for ease of maintenance and as an upgrade from rim brake components. Models from major manufacturers are listed below.
What is a Through Axle? Types and How to Choose
Through-axle is becoming a major fixation method for disc brake wheels. What is a through-axle? Here is a summary of what types are available.
Difference between 700C and 650B, advantages and disadvantages
With the popularity of gravel road bikes and the spread of disc brakes, the choice of road bike wheel size has become not only the standard 700C, but also 650B. In this issue, we will look at the differences between 700C and 650B, and the advantages and disadvantages of each.
Types of disc brake rotors and how to select them
Disc brake rotors are an unassuming part, but they have a significant impact on the effectiveness of disc brakes. We have compiled a list of the different types of rotors, how to select one, and the lineup of rotors from major manufacturers.
Disc brake pad types and selection
Brake pads are installed on the calipers of disc brakes. In fact, there are multiple types in terms of material and shape. The following is a summary of disc brake pad types and how to select the right one.
Summary of hex wrench sizes to prepare for road bike maintenance.
For those who will be servicing their road bikes, we have compiled a list of hex wrench sizes that are commonly used for road bike maintenance and that you should have available.
Latex Butyl? Different tire tube materials and how to choose the right one.
There are two types of bicycle tire tubes, latex tubing and butyl tubing. The following is a summary of the differences between the two and which one you should choose.
Guide to Choosing Binding Pedals for Road Bikes
Binding pedals allow you to ride faster and more efficiently on your road bike. In this article, we will thoroughly explain what to look for when choosing binding pedals.
Summary of binding pedal cleat types and their respective characteristics
Cleats are the parts that connect binding pedals to shoes. Cleats are only one part, but each manufacturer has its own characteristics and differences. They are actually important parts that are linked to usability and their merits and demerits.