Brompton BWR 6 speed sprocket set (13T/16T)
The sprocket set kit includes chain guard, sprockets (13T and 16T), spacer and circlip
This is a kit of parts making the BWR sprocket stack for fixing to the Brompton / Sturmey Archer wide range (hence BWR) 6-speed rear wheel hub
Also used on the Brompton Electric 6 speed rear wheel
What's in the pack? |
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The BWR-6 sprocket set pack contains the following:
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| Note: The BWR sprockets have a 9-spline Shimano style fitting - so will not fit the SRAM / Sachs 6 speed wheel - for that you would need the (discontinued) SRAM 6 speed sprocket stack which uses an ISO 3 spline fitting (we created a work-around solution for that) |
We made this YouTube video (below) to show how to remove the existing sprocket stack and install a new one
Chain / Chain Length |
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The chain required for this sprocket set depends upon the number of teeth on the front chainring: We recommend changing the chain when you change the sprockets |
Note: If you were looking for a higher gear - you could use the 12/16T combination (though this isn't strictly recommended by Brompton as it leads to some overlapping gears)
Compatibility: |
Which hub / rear wheel is the BWR sprocket stack for?
The Brompton BWR-6 sprocket stack is for the Sturmey Archer / Brompton developed hub used on the 16 inch wheel size 6-speed Brompton folding bikes
Below is a picture of the Brompton BWR hub (with sprockets attached) - sometimes it is labelled Brompton Wide Ratio
The BWR is actually an internally geared 3 speed hub, but as you can see from the above picture it has two sprockets (normally 13 tooth and 16 tooth) which work in combination with a proprietary Brompton derailleur system - giving 6 gears in total
The sprockets on the BWR hub use a Shimano style 16 spline shape on the inside - this means they will only fit onto the hub driver the correct side facing you (one of the 16 splines is wider than the others)
Below is a picture of a (slightly dirty - to show it is a real one!) BWR hub driver (where the sprockets fit to) with the sprockets removed - so you can see the Shimano style spline shape. The one on the top just to the right is wider than the others, ensuring that the sprockets can only be fitted the correct way around
Brompton BWR sprocket set installation |
The sprockets are held in place with a circle / C-ring
Tools required for installation: |
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The pack consists of: Installation sequence |
1/ Install the chain guard disc |
The chain guard disk is fitted first, it is keyed so it will only fit onto the diver in the correct direction. It protects the hub from dirt coming off of the chain
Simply slide the chain guard disk onto the driver and push so it's snug against the spokes
2/ Install the 16 tooth sprocket |
The 16 tooth sprocket used on the BWR wheel is keyed for the Shimano splined system - which is good as it means that you can't put it on the wrong way around
The sprocket is 1.8mm thick and has an individual Brompton Q part code of QRSPR16DR-SHMNO
There is a small triangle on the sprocket which points to the large spline - making alignment a bit easier
It is the same sprocket as is also used on the 2 speed Brompton rear wheel
Below is a picture of the 16 tooth sprocket installed on the BWR wheel
Simply slide on the 16T sprocket so that it is snug against the chain guard disk
3/ Install the spacer |
The spacer included with the kit is 2.2mm wide, and is not keyed for the driver (though in the past we have seen keyed spacers)
It fits between the two sprockets to keep them the correct distance apart for the derailleur to function correctly and to make the sprocket stack the correct total width to be held firmly in place by the circlip
The below picture shows the hub with the spacer now installed
4/ Install the 13 tooth sprocket |
Next on is the 13T sprocket. It is also keyed to prevent it being installed the wrong way around
The 13T sprocket is 3.1mm thick and also available as individual Brompton Q part reference: QRSPR13DR-SHMNO (Note: This Sprocket is not compatible with 3 speed Sturmey Archer hubs - BSR, AW, SRF-3)
5/ Install the circlip |
Last up is the circlip (also going by various other names). It is just a piece of metal with a split allowing it to open slightly for installation onto the driver where it sits in a groove holding the whole sprocket stack in place
Simple but effective!
This is where you will need a tool (there are special circlip pliers, but a small flat headed screwdriver is sufficient)
The circlip is installed to sit in the groove on the driver
The picture below shows the circlip successfully installed - there will be approx a 5-10mm gap as shown
Now you can re-install the wheel, make sure your hub gears are set up correctly and are free to go ride your six speed BWR Brompton off into the sunset!
Brompton 2020 Q part code: Q101615
Brompton Q part code: QRSPRSTACK-BWR6
Brompton part number: 9024162