Brompton derailleur chain tensioner
Chain tensioner for 2 and 6 speed Brompton folding bikes
This chain tensioner is for Brompton folding bikes with 2 speed, 6 speed SRAM or 6 speed Sturmey Archer / BWR (Brompton Wide Ratio) gears
This can be identified by the fact it has 2 identical looking black jockey wheels where the chain sits in a groove in the jockey wheel
This works as a chain tensioner (keeping the chain tight when riding and folded) and as part of the Brompton designed derailleur mechanism - by having juckey wheels which can move from side to side to allow the chain to move between the two rear sprockets
To make your chain tensioner last as longer - keep your chain clean and not over lubricated
Fitting instructions are included or can be viewed in the downloads tab
Weight: approx. 143g
If you have a single, three or five speed Brompton (i.e. no derailleur) then you need the standard chain tensioner (QCTA)
We made this short video to help identify which chain tensioner you have, as well as how to remove and install it
We also made this video about how the chain tensioner fits into the Brompton derailleur system and how to adjust that
Brompton 2021 Q part code: Q101507
Brompton original Q part code: QCTADR
Brompton part number: 9023011
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