RAR FIRST Hubs

For our fifteenth year of production, we have refined our RAR FIRST hub range.

This latest evolution elevates the performance and capabilities of our hubs, with RAR FIRST achieving a level of maturity rivaling the most prestigious hubs on the market.

Their longevity, ease of maintenance, and exceptional performance align with the guiding principles RAR has instilled in its wheels from the start.

The wheels are enhanced with a new gear mechanism and a drastic weight reduction.

RAR FIRST draws on the expertise and experience gained from producing high-performance wheels and exclusive RAR ESO hubs.

RAR FIRST becomes the heart of our road, gravel, and MTB ranges.

WEIGHT

Each design leverages ongoing structural analysis research.

The RAR FIRST disc road hub pair now weighs just 323g with oversized bearings.

The off-road RAR FIRST BOOST version tips the scales at 369g per pair, also with reinforced bearings.

RAR FIRST enters the realm of lightweight hubs.

GEOMETRY

These hubs are the culmination of over a decade of development. The results enhance effort transmission through finely optimized geometry.

Improvements include, but are not limited to, spoke positioning relative to the rim, spoke anchor diameters, and the rigidity of the axle-clamping system. Optimal mechanical balance of spoke tensions increases reliability and perceived dynamics on the bike.

MECANICS

The RAR FIRST V2 series operates with a ratchet mechanism. One ring is screwed into the hub body, while the second slides into the freewheel body via a spring-loaded blade.

Their 36 teeth provide a 10° engagement angle: an ideal balance to minimize freewheel friction and ensure rapid engagement during acceleration.
As a critical component for effort transmission, steel is the perfect material for this application.

BEARINGS & AXLE

A critical element: the bearing.

Wheel performance hinges partly on this component.

For maximum efficiency, the hub must feature bearings sized proportionally to the loads received, ideally exceeding them for absolute reliability.

We prioritize large-section bearings across the RAR FIRST V2 range, using ISO 61902 or 6902 bearings: 15mm inner diameter, 28mm outer diameter, and 7mm thickness.
This offers a triple advantage:

  1. 5/32-inch balls provide the smoothest rolling between races, minimizing friction.
  2. The dynamic strength of these bearings far surpasses that of 61802 or 61803 bearings (with 3/32-inch balls), typically used to save weight.
  3. These bearings are more tolerant to shocks and contaminants due to the size of their rolling elements.

Exceptions to the 61902 are made for low-load applications: front rim-brake hubs, rear rim-brake hubs (non-cassette side), and front disc-brake hubs (non-disc side), where 61802 bearings made more sense.

To maximize bearing performance, a precisely designed axle is essential.<
Our axle features shoulders perfectly aligned with bearing races to relieve lateral stress, extending their lifespan.
Clamping stresses are distributed via spacers across the entire axle.

Bearings in the freewheel relieve those in the hub body, and vice versa. RAR FIRST uses a nested or screwed cap on the axle, eliminating adjustment needs and preventing misalignment.