The Rennen Ultralite Mini Bottom Bracket is an engineering masterpiece. We set forth to develop the lightest and smallest bottom bracket in the world, but we did not stop there and made the bottom bracket adjustable.

The adjustable feature includes a bearing cup with a taper thread lockring/expanding shell design. This allows the user to precisely adjust their chainline. Once set we provide special tools to lock the cup in place and allow precise control over bearing pretension and chainline adjustments. Check out the installation video here.

Specs:

- Our 95mm option weighs a mere 77g w/out screws (90g w/Ti, 80g w/7075). Spindles are available in 5mm increments up to 115mm.

- The unique 20mm aluminum 7075-T6 spindle has been oversized to increase strength while keeping the weight low.

- The spindle features M8x1mm stainless steel helicoil threads to ensure confidence in its strength and holding torque capability.

- The Rennen Ultralite Mini Bottom Bracket uses Enduro ABEC 5 Silicon Nitride Ceramic bearings. Enduro is the leader in high performance bicycle bearings. When designing the best mini bottom bracket it only makes sense to use the best bearings.

- Titanium spindle bolts come standard but the serious Factory Dad can upgrade to an Aluminum 7075-T6 bolt for maximum weight savings and bling factor.

80 lb Weight Limit - Due to the extreme weight reduction design we recommend that this product not be used for a child weighing greater than 80 lb.