Road Boost Compatibility Explained

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Road Boost Compatibility Explained

Road Boost is a byproduct of e-bikes proliferating into Gravel and Road categories. Not an innovation in itself its proclaimed benefit of stronger wheels is dubious. Don’t we have Boost already? Designated almost identically it is somewhat compatible with Boost, but not exactly. We uncover and explain the details of Road Boost compatibility and its relations to other standards.

The list of standards with Boost designation is confusing. We covered Boost and its relation to classic, once standard MTB hubs, earlier. Read on to how to convert non-Boost to Boost. Explained what its downgraded variant Boost QR or Boost 141 as all about. And looked at the details of one standard with several names. Which, yet, stands on its own for genuine reasons – Super Boost Plus or SB+, also known as Trail 157.

Front hubs Road Boost and Boost compatibility. Gravel (left) 12 mm axle, XCR (right) either 12 mm or 15 mm axles.
Front hubs: Gravel (left) 12 mm axle, XCR (right) either 12 mm or 15 mm axles

There are many attributes that Road Boost shares with Boost. It got the same Over the Locknut Dimension (OLD): 148 mm rear and 110 mm front. The rotor mount offset is unaltered. So is the chainline: With e-Road bikes there is a clear need to have more space at the bottom bracket unit. An increased chainline makes sense.

These similarities suggest that Road Boost is compatible with Boost. And to some extend this is correct. But what is different between Road Boost and Boost than?

The front thru axle is 12 mm, instead of 15 mm. The specification for the Road Boost front reads 110×12 vs 110×15 for Boost. Regular Road or Gravel hubs are 100×12, so Road Boost brings those 10 extra mm of width. The increase in wheels bracing angle drives up its strength. Effectively it catches up with performance characteristics of MTB wheel. If not for the 12 mm axle.

What if one gets regular Boost front hub and adopts the 12 mm end caps instead of 15 mm? It would than quality for the Road Boost standard. Alternative is the “native” 12 mm front hub, which does not allow for 15 mm axle by design. The benefit is ~20 g of weight saving at the expense of versatility. The estimate is based on the comparison of Gravel and XCR front hubs. Check the photo above.

Trailmech XCR front hubs are available in either 110×12 mm or 110×15 mm. To convert between the two standards simply replace the end caps. Whilst Gravel front hub won’t accept 15 mm axle, no matter the OLD – 100 mm or 110 mm.

Rear hubs compatibility between Road Boost and Boost is even more subtle. Both Road Boost and Boost rear hubs are identical from OLD point of view, as they are 148×12 mm. Is it possible to use Boost, that is MTB, rear hubs with Road Boost frames? Well, it depends. And the nuance is the driver train. With narrow range Road cassette either 11 or 12 speed Boost hub is unlikely an option. With wide range MTB or certain marketed as Gravel cassettes – regular Boost hub works just fine – XCR. We cover why this is the case in Shimano HG MTB and HG Road freehub compatibility.

If you are running Campagnolo’s 11, 12 or 13 speed drive train, than you need genuine Road Boost rear hub. At present we do not offer Gravel rear hubs in Road Boost 148×12 spacing.