Currently, Shimano is the most popular groupset choice among bike manufacturers. The component giants have a range of offerings, in ascending order of efficiency (and cost), mechanical groupsets include: Shimano Claris, Shimano Sora, Shimano Tiagra, Shimano 105, Shimano Ultegra, Shimano Dura Ace.
Shimano use STI’s levers – which stands for ‘Shimano Total Integration’. The shifters have two levers – a big one, and a smaller little one behind it.
Trek Silque SL 2015 Womens Road Bike Reviewed
The left shifter controls the front derailleur, and thus the chainrings. From Tiagra onwards, to change into a larger chainring, adding more resistance, you press in with the biggest lever. When you want to make is easier to pedal, you can change into a smaller chainring, by pushing in the smaller lever.
The right shifter controls the rear derailleur – allowing you to make smaller changes on the cassette. When you want to change into a gear that provides more resistance, for a flat piece of road, you push in with the smaller lever. When you want to make it easier to pedal, you press in with the larger lever.
