Front Derailleur Types For Mountain Bikes.

[SickBiker]

There are three main factors you want to consider before buying a new front derailleur for your Mountain Bike: the assembly system, swing design and cable pull type. It is not really complicated to find out what front mech will fit your bike and I explain that in this article...

Front derailleur installation types:

1. clamp on - the front mech usually comes with shims, so that we can fit the clamp to different seat tube diameters (28,6mm, 31,8mm, 34,9mm),
2. Direct Mount - the derailleur is secured directly to the frame with one bolt,
3. E2-Type - the derailleur is also secured directly to the frame, but with two bolts (E-Type was the previous generation).

Standard, clamp-on front derailleur.

Direct Mount front derailleur.

E-Type front derailleur (aka E2-Type)

The derailleur swing design:

1. High Clamp / Down Swing - the clamp is located above the swing,
2. Low Clamp / Top Swing - the clamp is located below the swing,
3. Side Swing - the derailleur swings sideways and is pulled from the front of the bike).

Down Swing / High Clamp front derailleur symbols.

Top Swing / Low Clamp front derailleur symbol.

Low Clamp on the left. High Clamp on the right.

Side Swing rear derailleur.

Vertically positioned spring on Side Swing derailleurs.

The cable pull type:

1. Top Pull - the cable is routed on the top tube of the frame and then goes down to the derailleur,
2. Bottom Pull - the cable goes by the down tube, then under the bottom bracket and goes up to the front mech,
3. Dual Pull - the design of the derailleur fits both bottom and top pull systems,
4. Front Pull - Side Swing derailleurs will have the cable coming from the front of the bike.

Dual Pull front derailleur.

Dual Pull systems allows to guide the cable from either sides.

Front Pull system is used only on Side Swing derailleurs.

The cable comes through the guide from the front.

Top Pull derailleur symbol.

These two silver bolts on the side of the seat tube indicate, that we can use here the Direct Mount front derailleur (the adaptor comes FIRST). If there were two bolts, but positioned much lower, that would fit the E2-Type derailleur. No bolts or threads at all means - buy the clamp-on rear derailleur.