The default Brompton gearing is great for most people, but if you're carrying cargo, not in peak shape, or are a particularly strong rider, you might want to have us alter the gearing. Just add the chainring of your choice to your cart. No labor charges will be added when when purchased at the same time as a Brompton. All parts will be professionally installed and adjusted with the chain length set to the correct length. Any original parts removed will be included with your order. Questions? Just ask. The table below illustrates the options available for each Brompton, depending on the number of speeds on the bike.