Wolf Tooth Components Elliptical Direct Mount Flattop Chainring for SRAM Cyclocross / Road

This oval Direct Mount chainring by Wolf Tooth Components can be used for SRAM road, gravel and cyclocross cranks and is also compatible with Flattop chains.

Specifications:

Application:

Cyclocross, Gravel, Road

Mount:

SRAM Direct Mount

Teeth:

38 T, 40 T

Gearing:

1x9-speed, 1x10-speed, 1x11-speed, 1x12-speed

Type:

10 % oval

Technical Information:

Offset:

6 mm

Chainline:

45.5 mm / 47 mm / 47.5 mm

Material:

aluminium (7075-T6)

Compatibility:

Rear Over Locknut Dimension:

• quick release: 135 mm
• thru-axle: 142 mm

Crank:

• SRAM Cyclocross, Gravel and Road Cranksets
• Praxis Works Road-/CX-cranks
• also suitable for SRAM Direct Mount GXP cranks and BB30 cranks with long axle (101.5 mm)

Chain:

• all 9-speed, 10-speed and 11-speed chains
• SRAM Flattop, SRAM Eagle, Campagnolo and KMC 12-speed chains
• 10-speed chain recommended for 9-speed drivetrains

Features:

• Wolf Tooth PowerTrac Elliptical and Wide-Narrow design
• increased and more even pedalling performance, more efficiency in the recovery zone and more traction thanks to constant torque
• timing: 112° to TDC (Top Dead Center)
• standard chainline (6 mm offset)
• Made in the USA

Note from the Manufacturer:

Please reuse the 3 original spider bolts to directly mount the chainring or buy Wolf Tooth spare bolts (installing/removing is best done with T25 L-key). Damped rear derailleur recommended.

Technology:

PowerTrac Elliptical™ (PTE)
Wolf Tooth's PowerTrac Elliptical chainrings feature 10% ovality, in combination with 112° timing, which is measured according to the Top Dead Center (TDC). This means that the chainring section with a wider diameter engages the chain at the optimum point in the downward movement, the power zone. In this way the natural biomechanics of the body are taken into account.

PTE is like having two chain rings in one. This is because your pedal stroke is biomechanically weakest when your pedals are at the upper and lower positions of the circle (at 11 to 1 o'clock and 5 to 7 o'clock on a dial), also known as the " recovery zone" . Thanks to the oval shape of the chainrings, the narrower section grips at this stage, which makes it seem as if you have two chainring teeth less. It's as if you were instantly shifting to a smaller chainring, for example from 34 to 32 tooth.
The reverse is true for the power zone of your pedal stroke - when your front pedal is at 1 to 5 o'clock. Here, when your legs are at their strongest and most efficient, the PowerTrac elliptical has a wide diameter and works as if you have two extra chainring teeth, about 36 instead of 34.

The whole thing also benefits traction. The torque on the rear wheel is more even, so the probability of you overpowering and slipping in the power zone is reduced. It also makes pedalling easier in the recovery zone and maintains momentum. This " 2 chainrings-in-1" effect keeps the pedal stroke smooth and the torque constant at every stroke.

Drop-Stop® B
Wolf Tooth has invested countless hours in the design, prototyping and testing of their Wide-Narrow chainrings and has developed a highly innovative tooth profile. Test riders around the world have confirmed that this design brings unparalleled performance.
The right side of the chainring tooth has a different shape than the left side. The right side transmits the power to the chain and the left side opens a free space for cleaning mud and dirt. Since the two sides have completely different functions, it makes sense to design them differently, true to the motto: extra reinforcement where you need it, less material where you don't.
The right side of the Drop-Stop tooth is as wide as possible to distribute the load over a larger area, which also minimises wear. The left side of the Drop-Stop tooth helps to guide the chain, but it does not transmit any load. Therefore the left side is narrower than the chain roller. Wear is not an issue on this side, so Wolf Tooth was able to save material and create a better mud clearance channel. More free space means less friction and less change of the chain being dropped due to mud.
In the B version, the drop-stop profile is optimised for use on wheels with drop bars. The teeth are slightly narrower and the valleys between the teeth are deeper to accommodate the larger rollers of SRAM Flattop chains. The outer sides of the narrow and wide teeth touch the chain to guide it.

Manufacturer Numbers:

38 tooth:

OVALSDM38FT

40 tooth:

OVALSDM40FT

Contents:

• 1 x Wolf Tooth Components Elliptical Direct Mount SRAM Flattop Chainring