TRiPEAK Jetstream Pro Ceramic Pulley Wheel 12T/18T | Shimano 11/12s | Asymmetric Oversized Pulley Wheel (AOPW) OSPW

12T upper / 18T lower oversize pulley | NC Race G3 ceramic bearings | Patented asymmetric frame | 4-year warranty

Upper pulley 9g | Lower pulley 30g | Supra LV lubricant included

Oversized pulley wheels reduce chain deflection angle and rotational resistance.

What TRiPEAK solved with the AOPW is the installation problem. Fitting an 18T lower pulley into a standard Dura-Ace cage normally requires chain length adjustment and cage modification. TRiPEAK's patented asymmetric frame design allows the 18T pulley to fit the original derailleur cage with minimal modification, installed with nothing more than a hex wrench.

The JetStream Pro bearing system consists of NC Race nano-coated races, G3-grade ceramic balls, zero-contact seals, and Supra LV low-viscosity lubricant. 

Features

Patented Asymmetric Frame Design

TRiPEAK's asymmetric pulley frame is the key engineering feature that makes AOPW work without the usual installation headaches.

By offsetting the frame geometry, the 18T lower pulley fits within the envelope of the standard cage.

No chain length adjustment required in most cases, though checking B-tension spacing after installation is still recommended.

18T Lower Pulley — Reduced Chain Deflection

18T significantly reduces the chain wrap angle compared to the original 11T lower pulley.

Less angle = less deflection = less energy lost to chain articulation at that point in the chain.

Injection-Moulded PA+GF Pulley Body

The pulley body is injection-moulded from a PA+GF (polyamide + glass fibre) composite rather than machined aluminium.

Injection moulding fully encases the bearing with a zero-tolerance fit. There's no press-fit gap between bearing and pulley body that can introduce play or noise over time.

The composite material is also more wear-resistant than aluminium against chain contact, which extends the service life of both the pulley and the chain itself.

Narrow-Wide Tooth Profile

The pulley uses a narrow-wide tooth pattern that alternates tooth thickness to match the inner and outer links of the chain.

This improves chain retention on the pulley and reduces the chance of chain skip under hard acceleration or rough road conditions.

Hollow Frame Design

The 6061 aluminium pulley frame (cap) uses a hollow structure that increases bearing diameter without adding weight.

A larger bearing running at the same RPM has better load distribution and longer service life. The hollow design also reduces the impact of any debris intrusion on rotational consistency.

NC Race G3 Ceramic Bearings

NC Race bearings feature a nano coating on both inner and outer races, reducing the dynamic coefficient of friction to as low as 0.03.

G3-grade ceramic balls are precision-ground to tighter sphericity tolerances than standard ceramic bearings, lowering rotational resistance and extending bearing life. TRiPEAK backs the JetStream Pro bearing system with a 4-year warranty.

Zero Contact Seal

The bearings use a non-contact seal that fully covers the bearing race without physically touching the inner ring with greatly reduces drag.

Zero-contact seals provide coverage and protection without the friction penalty.

Supra LV Low-Viscosity Lubricant

Supra LV is TRiPEAK's ceramic-specific low-viscosity lubricant.

It's formulated for high-speed, low-load applications like pulley bearings. Easy to maintain without removing the bearing seal.

Specifications

What's Included?

• TRiPEAK Asymmetric Oversized Pulley Wheel 12T Upper Pulley
• TRiPEAK Asymmetric Oversized Pulley Wheel 18T Lower Pulley of your chosen colour
  

Installation

Installation requires only a standard hex wrench with no chain removal or length adjustment in most cases.

After installation, check chain length and B-tension spacing before riding.

Download PDF Installation Manual.

Links

View the TRiPEAK Collection Here
View other Pulley Wheels Here