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
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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 |
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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.
Essential Special Tools for Installing and Servicing 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 |
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