Bionicon/B-Labs B-Ring Narrow/Wide Oval Chainring BCD 104

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Bionicon/B-Labs B-Ring Narrow/Wide Oval Chainring BCD 104

The 1-by - drivetrain solution has been embraced by riders worldwide looking for a simpler, lighter and cleaner bike set-up.

Losing 2 or 3 front rings reaps numerous benefits but the major drawback is the decreased range of gears making long or steep climbs a real struggle.

Elliptical chainrings ease the pain by creating a virtual gear ratio, which effectively varies by -2 or +2 teeth during each turn of the pedals.

The downside of elliptical rings is the decreased shifting quality when used with multiple ring drivetrains.

The B-Ring OVAL is a win-win-win upgrade for all 1 by 9/10/11 transmissions!

The alternating tooth profile ensures your chain stays put on the chainring without requiring use of an upper frame or BB mounted chain guide or clutch style rear mech. For ultimate peace of mind use a c guide ECO to add chain security and cut down on noise.

Virtual gear range - roadies, triathletes and XC racers have long known about the benefits of using oval shaped chainrings. It´s elliptical shape provides you more torque at your weak-spot of the crank position. This means, that it virtually gives you -2 teeth lighter gears in your crank weak-spot and +2 teeth harder gears in your sweet-spot.
Also: Your pedalling will noticeably become more steady and homogeneous! At first you might think not to feel a difference? Well, then try to get back to normal circular ring and see, what happens...

Offset chainline - replacing 2 or 3 chainrings with a single ring can open a whole can of chainline worms. Our BCD104 and the direct mount rings create a narrower chainline than standard 2x10 or 3x10 cranks on the equivalent chainring. Also B-Rings have a narrower chainline than other 1-by chainrings. The benefits of our increased offset design are:

  1. less (better) chain-angle/wear in low gears because of reduced diagonal chain run
  2. less friction in low gears (where you can literally hear the friction with every painful stroke on the pedals ;-)) due to reduced diagonal run of the chain
  3. reduced noise in low gears

Thread mount - You mount the chainring only with one standard chainring bolt, the thread is machined into the chainring. Until now chainrings were fixed by a 2 part bolt system. When tightening the outer part the inside fixing inevitably rotates. Unless you have the special tool for holding the inner part fitting chainrings often ends in bloody knuckles or creaking drivetrains. Getting rid of the inner bolt part saves weight, reduces fitting hassles and helps keep your skin where it should be.

Chainlines with SRAM Cranks (mm)
2x10 crank 3x10 crank
GXP,PF30/BB30 long spindle GXP,PF30/BB30 long spindle
X9,X0,S1400,S2210 X9,X0,S1400,S2210
Original chainline 2nd ring 53 51
Teeth Weight
32 40g 50.6 49
34 48g 50.6 49
36 58g 50.6 49
Chainlines with Shimano Cranks (mm)
2x10 crank 3x10 crank
- -
Original chainline 2nd ring 52.7 50.6
Teeth Weight
32 40g 51 48.5
34 48g 51 48.5
36 58g 51 48.5
Condition: New


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