This is a replacement Brompton 54 tooth chain ring complete with guard. It is used to replace a worn 54T chain ring or to increase the gearing if you currently have a 44T or 50T chain ring

Chain ring colour: silver
Chain ring guard colour: black

The chain ring is also available in black (this option was originally introduced on black edition models) at a slightly higher price

About the Brompton 54 tooth chain ring and guard 

The Brompton Spider crankset was introduced on new Brompton bicycles at the beginning of 2013 in conjunction with the change to ISO bottom brackets

One of the main benefits of the this crankset over the previous versions is the ability to be able to change the gearing without having to change the complete crank set

Another improvement over previous models is that the chain guard is now held onto the chain ring with screws - previously it was held on with plastic lugs which wasn't as secure, so sometimes the chain guard would fall off

The chain guard is not strictly necessary - but helps to prevent getting your dress / trousers rubbing on the chain / chain ring and getting dirty

Changing the Brompton chain ring and guard

The chain ring - complete with guard - can be changed (it is held on with 5 chain ring bolts - not included - as opposed to being moulded to the crank arm like the previous crankset) to alter your Brompton bicycles gearing. You also need to change the chain accordingly 

It can be used to replace the 44, 50 or 54 teeth chain rings on a spider type crank

This 54 tooth chain ring is the standard on 1 and 2 speed Bromptons from the factory or on a 3 speed with higher gearing from the factory

Changing from the standard 50 tooth 3 speed to 54 tooth will increase your gearing by approx. 10% making getting up hills slightly tougher but giving a higher top speed on the flat

This is a replacement Brompton 54 tooth chain ring complete with guard. It is used to replace a worn 54T chain ring or to increase the gearing if you currently have a 44T or 50T chain ring Another improvement over previous models is that the chain guard is now held onto the chain ring with screws - previously it was held on with plastic lugs which wasn't as secure, so sometimes the chain guard would fall off The chain ring - complete with guard - can be changed (it is held on with 5 chain ring bolts - not included - as opposed to being moulded to the crank arm like the previous crankset) to alter your Brompton bicycles gearing. You also need to change the chain accordingly  Changing from the standard 50 tooth 3 speed to 54 tooth will increase your gearing by approx. 10% making getting up h