UltraPulley from 9.8g/set

Minimize friction and mass

Weight: see table below

Sealing: low friction 2RS seals

Construction: twin-bearing system

Bearings: High Grade Stainless Ceramic Bearings

Material: self-lubing hi-tech polymer and AL7075 inserts

Compatibility: nearly every rear mech (see details on the table below)

Extralite Pulleys have been developed and continuosly evolved for over 15 years

Extremely lightweight and performing, weighing half of the competitors

Thanks to their unique engineering layout they provide the lowest resistance you can find today

Rolling smoothness is enhanced by custom super-low-friction stainless ceramic bearings featuring proper sealing too

Each pulley wheel features a twin-bearing assembly for unmatched stability and shifting precision

Pulley body and teeth are 3D machined from highly durable polymer that's well self-lubing too


Complete Kits

Direct replacement for
Upper position
Lower position
Weight (set)
UltraPulley 11-11
Sram Red / XO
Shimano Road 11/12s - MTB 10/11s
Campa 10/11/12s
11T Not Phased *
11T Not Phased *
UltraPulley 12-12
Di2** and Shimano road 11/12s
Sram Road AXS
12T Not Phased *
12T Not Phased *
UltraPulley 13-13
Shimano MTB XRT-XT 12s
13T Not Phased *
13T Not Phased *
UltraPulley 12-12 PH
Sram XX1-XO1-GX 11s
12T Phased *
12T Phased *
UltraPulley 12-14 PH
Sram XX1-XO1-GX Eagle 12s
12T Phased
14T Phased
UltraPulley 14-16 PH
Sram XX1-XO1-GX Eagle 12s
14T Phased
16T Phased
UltraPulley 14-16 PHB
Eagle XX SL-XX-XO AXS 2023
14TB Phased AXS
16TB Phased AXS

* Interchangeable for upper or lower position
** Di2 12s requires ExtraBolt 12.2C or equivalent M5x15.5mm bolts

Pulley Bolts
All UltraPulley models are equipped with a twin-bearing system and their width at the bolt fitting is 8.4mm
Their fitting into derailleur cages proved to be fine on any common setup however in some cases it may require a different bolt length than the original
We always suggest to check well your setup before ordering and eventually use the the following Extralite bolts (or equivalent)
ExtraBolt 12.2 are
specifically designed for derailleur pulleys and are available in 3 different lengths
ExtraBolt 12.1 are less specific but very versatile and can
generally offer a good fitting too


Single Pulleys for Custom Setups

Diameter ( with chain )
Thickness at bolt fitting
UltraPulley 11T
Upper and/or Lower
UltraPulley 12T
Upper and/or Lower
UltraPulley 13T
Upper and/or Lower
UltraPulley 12PH
Upper and/or Lower (Phased)
UltraPulley 14PH
Upper and/or Lower (Phased)
UltraPulley 16PH
Lower (Phased)

Tuning Tips

Phased pulleys were born to help guiding the chain on MTB single chainring systems and can fit road systems too
Pulleys with phased teeth (PH) can be applied also on standard double chainring systems with the benefit of a higher shifting precision

Most derailleur cages can fit pulleys with one or more teeth than the original
However each setup differs slightly so you always have to analyze it specifically
As example Dura Ace 11/12s has been positively tested with 12-12PH , 12-14PH and 13-13

How to check the clearance of your cage at each pulley
Measure the distance from the center of pulley bolt to the inner edges of your derailleur cage
The table above reports the max diameter for each pulley model with chain installed
Divide by 2 the pulley diameter (with chain) and compare the result with your cage clearance

If you plan to fit UltraPulley 12PH in the upper position note that it behaves differently and more precisely than a regular 12T
UltraPulley 13T is not phased however the wider diameter keeps the upper pulley a bit closer to cogs and that may add precision in some setups too

The kind of possible improvements are part of your personal tuning process and taste, no written rules to project your ideal setup

Stability and Friction of the Rotation System

All UltraPulley models feature the most advanced spinning system currently in use
The system is based on 2 paired-micro-ceramic-bearings on each pulley instead of one-big-bearing per pulley as most others

Which are the advantages?

Two paired bearings on each pulley stabilize the lateral play and virtually eliminate any left-to-right play, similarly to a front wheel-hub
Note that a single-bearing pulley can't even get close to this level of lateral stability

Friction minimization
Apparently two bearings could increase the overall friction but actually that's not the case
Thanks to the vastly improved rotating geometry described above the bearing size can be minimized
The smaller difference between inner and outer races reduces ball rotation friction way under the 50% of what is generated by one single-big-bearing
Our custom-made High Grade Hybrid Ceramic bearings further enhance the quality of UltraPulley rotating system, allowing the lowest friction factor of the whole bike-tuning industry
All that with the proper protection of low-friction 2RS seals and the advantage of non-rustable stainless bearings too

100% made in Italy