The Brompton Crankset 50T is a replacement set with left and right hand crank, including chainring and chainguard, as found on post 2013 Brompton Bikes.
A standard 3 or 6 speed Brompton comes with a 50 tooth front chain ring.
A standard 1 or 2 speed Brompton comes with a 54 tooth front chain ring - changing to 50 teeth will decrease the gearing by approx 7%.
The Bottom bracket is NOT included - If upgrading from the old fixed crankset then you will also need to change the bottom bracket (the old one was ISO standard and the new one is JIS standard).
Brompton is committed to quality; if our products have failed you in any way, please return them and we will either exchange them or give you your money back. If the product is faulty or has arrived damaged, we will reimburse the cost of return postage. Unwanted items may be returned within 28 days at your cost.