Have you ever had shimano part numbers explained to you? Each Shimano bike component comes with a unique part number. This not only helps us to define what kind of part it is but also what kind of cycling it is designed for, which generation it belongs to and if there are any variations within the part. Once in a while Shimano upgrades model numbers on their components which makes them even harder to follow. Luckily there is a pattern which we will reveal to you.
If you’re not sure where to look for the number on your Shimano part then visit our article here.
You can also watch this video:
Shimano part numbers explained
Up to 2016 mountain bike, trekking and non-series bike part codes would usually consist of 3 letters and 3 numbers (AB-C123).
The first 2 letters (AB) indicate what type of component it is.
The third letter (C) specify the style of bike.
The first number (1) indicates which group set the part belongs to.
The second number (2) indicates a change in the generation of the component.
The third number (3) indicates a small change of the component within its generation.
Pre 2016 road bike component codes (within the groupset range) consisted of two letters and 4 numbers (AB-1234).
The first 2 letters (AB) indicate what type of component it is.
The first number (1) indicates which group set the part belongs to.
The second number (2) indicates a change in the generation of the component.
Between 2014 and 2017 Shimano changed the codes for their components adding another number to the mountain bike and trekking components (AB-C1234) and the letter “R” to the road components within the group sets (AB-R1234) but with the exception of the Tiagra groupset.
The first 2 letters (AB) indicate what type of component it is.
The third letter (C/R) specifies the style of bike.
The first number (1) indicates which group set the part belongs to. The higher the number the better the quality groupset it is.
The second number (2) indicates a change in the generation of the component.
The third number (3) indicates compatibility within its groupset family.
The fourth number indicates a small change that doesn’t affect compatibility in the family.
Shimano part numbers explained – pre 2016 MTB and trekking components
Up to 2016 mountain bike, trekking and non-series bike part codes would usually consist of 3 letters and 3 numbers (AB-C123).
The first three letters
The first 2 letters (AB) indicate what type of component it is, for example:
FD for front derailleur, RD for rear derailleur, FC for front chainwheel, CS for cassette, BL for brake lever, BR for brake caliper, SL for shift lever, ST for Shimano total integration, HB for front hub, FH for freehub body hub.
The third letter (C) specify the style of bike, M for mountain bikes, T- for trekking bikes.
The first number
This number (1) will be between 2 and 9 and it indicates which group set the part belongs to.
The higher the number the better the quality groupset it is. For example:
Between 1999 and 2013 the numbers represented:
3 for Acera and Altus groupsets,
4 for Alivio groupset,
5 for Deore groupset,
6 for SLX groupset,
7 for XT groupset,
8 for Saint groupset,
9 for XTR groupset.
The second number
The second number (2) indicates a change in the generation of the component.
The number isn’t necessarily sequential but is always higher.
XTR groupset (9)
- 0 or 1 – 1st generation (1992 – 1995)
- 5 – 2nd and 3rd generation (1996 – 2002)
- 6 – 4th generation (2003-2006)
- 7 -5th generation (2007-2010)
- 8 – 6th generation (2011-2013)
XT groupset (7)
- 0 – 1st generation (1983 – 1986)
- 3 – 2nd generation (1987 – 1998)
- 5 – 3rd generation (1999-2002)
- 6 – 4th generation (2003 – 2007)
- 7 – 5th generation (2007 – 2010)
- 8 – 6th generation (2011 – 2014)
SLX groupset (6)
- 6 – 1st generation (2008-2011)
- 7 – 2nd generation (2012-2015)
Deore groupset (5)
- 1 – 1st generation (2000- 2004)
- 3 – 2nd generation (2005-2008)
- 9 – 3rd generation 2010-2013
Alivio groupset (4)
- 1 – 1st generation representing 8 speed (2005-2013)
- 3 -1st generation representing 9 speed (2010- 2013)
Acera groupset (3)
- 3 – 1st generation (1999 – 2001)
- 4 – 2nd generation (2002 – 2007)
- 6 – 3rd generation (2008-2010)
- 9 -4th generation (2011-2014)
The third number
The third number (3) indicates a small upgrade of the component within its generation. For example a Shimano XT rear derailleur RD-M786 will be equipped with a clutch compared to the RD-M780 model.
Shimano part numbers explained – pre 2016 road components
Pre 2016 road bike component codes (within the groupset range) consisted of two letters and 4 numbers (AB-1234).
The first two letters
These letters (AB) indicate what type of component it is, FD for front derailleur, RD for rear derailleur, FC for front chainwheel, CS for cassette, BL for brake lever, BR for brake caliper, SL for shift lever, ST for Shimano total integration, HB for front hub, FH for freehub body hub.
The first number
This number (1) will be between 2 and 9 and it indicates which group set the part belongs to. The higher the number the better the quality groupset it is.
Between 1996 and 2011 the numbers represented:
2 – Claris groupset
3 – Sora groupset
4 – Tiagra groupset
5 – 105 groupset
6 – Ultegra groupset
7 Dura ace groupset
The second number
The second number (2) indicates a change in the generation of the component. The number isn’t necessarily sequential but is always higher.
Shimano part numbers explained – 2014 onwards
Between 2014 and 2017 Shimano changed the codes for their components adding another number to the mountain bike and trekking components (AB-c1234)
and the letter “R” to the road components within the group sets (AB-R1234) but with the exception of the Tiagra groupset.
The first three letters
The first 2 letters (AB) indicate what type of component it is, for example: FD for front derailleur and ST for STI shifters.
The third letter (C) specifies the style of bike,
M for mountain bikes,
R for road bikes,
T for trekking bikes,
U for urban bikes.
The first number
This number (1) will be between 2 and 9 and it indicates which group set the part belongs to. The higher the number the better the quality groupset it is.
For mountain bikes the number represents:
2 – for Altus groupset
3 – for Acera and Alivio groupset
4 – for Deore groupset (10 speed)
5 – for Deore groupset (11 speed)
6 – for Deore groupset (12 speed)
7 – for SLX groupset
8 – for XT groupset
9 – for XTR groupset
For road bikes the number represents:
2 – for Claris
3 – for Sora
4 – for Tiagra
7 – for 105
8 – for Ultegra groupset
9 – for Dura Ace groupset
The second number
The second number (2) indicates a change in the generation of the component.
The third number
The third number (3) indicates compatibility within its groupset family. To be able to use the third number you need to look at compatibility within the part, (AB-C) the series (1) and the generation. (2). Two components can both be produced, fit on the bike with the rest of the groupset but not function. This will be because of a major difference in the structure or function of the bike.
Examples include whether a rear derailleur works electronically or not (RD-M9050 and RD-M9000).
The difference in the maximum drivetrain capacity of a rear derailleur when it is used with a single or a double chainring (For example Shimano XTR RD-M9120 is specifically designed with XTR FC-M9100 12 speed double drive trains whether the RD- M9100 is designed to work with XTR FC-M9100 12 speed single drive train) or the difference in chain sets needed to achieve the correct chainline (FC-M6100 where the Q- factor 172mm, FC-M6120 where the Q-Factor is 178mm and FC-M6130 where the Q-Factor is 181mm).
The forth number
The fourth number indicates a small change that doesn’t affect compatibility in the family. Here is an example. The ST-R8025 STI lever has a slightly smaller lever size than ST-R8020 STI lever.
Shimano part numbers explained – video tutorial
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