It often seems like we can spend all day every day explaining various aspects of different products. We are more or less tolerant of this to a fault, since we want people to be armed with the best info they can have before making a big purchase decision. BUT... it's also smart for us to document all that stuff so that it's always available for people when they want it, and it's more efficient for us. An investment, for sure, since this is taking me forever to write, but worth it. Anyhow, I'll divide them up into manageable chunks and post them as blogs before we put them in permanent spots on the site. Here's Part 1.
We offer a broad range of hub choices, partially because there are substantive differences between different hubs, and partially because hubs are a great way to individualize a set of wheels.
All hubs perform several basic functions:
1. They provide an attachment point between your wheels and your bike
2. They are the anchor point for the spokes
3. They provide the axis on which the wheel spins
4. Rear hubs house a significant amount of the bike’s transmission
5. Disc brake hubs transmit stopping force from the brakes to the tires.
Different hubs perform these different functions differently, which we’ll briefly explore. Then we’ll explain the pros and cons of each type of hub that we offer in order to help you make the best choice for yourself.
The Attachment Point
You’d think this would be simple but, you know, bikes – so it isn’t. Here goes…
- Quick release: Fork dropouts are 100mm apart, rear dropouts are either 130mm (rim brakes, usually) or 135mm (disc brakes) apart. The front dropouts are nominally 9mm diameter, while rears are 10. Advantages of this system are convenience, simplicity, and history – it’s been around a long time, so a lot of wheels are made to fit. Disadvantages are reliance on quick releases, which some people find difficult to master and some of which are poorly designed, and ultimately less security than thru-axle systems.
- 15x100 thru. Popular in cross country mountain bikes. A 15mm thru axle secures the wheel to the fork. The fork has holes instead of dropouts, and the hub ends butt directly against the fork. A very secure system, the use of the thru axle also provides additional torsion resistance to the fork. The specific thru axle that you’ll use is dependent on your fork.
- 12x100 thru. Functionally the same as 15x100 thru, this standard came about when it was decided that 15mm thru was “overbuilt” for cross, gravel, and road bikes.
- 12x142 thru. Rear axle standard for disc road, disc cross, and disc gravel bikes. Still popular on mountain bikes, for which it was originally developed. Provides a stiffer, more secure connection between hub and bike. The functional (and overall) width of a 12x142 hub is exactly the same as a quick release rear hub, so the wheel’s inherent stiffness is the same from one standard to the other.
- 110mm Boost. A wider front thru axle becoming popular for longer-travel mountain bikes. Slightly increases wheel stability thanks to wider flange spacing.
- 12x148 Boost. A wider rear thru axle becoming popular for longer-travel mountain bikes. Slightly increases wheel stability thanks to wider flange spacing.
- Lefty. Specific attachment for Cannondale Lefty (one legged) forks.
- Fat bike hubs – there are several fat bike width standards that are their own kettle of fish.
The Anchor Point for the Spokes
The main variants here are hubs for j-bend versus hubs for straight pull spokes. While there are arguments that straight pull spokes resist fatigue better as the potential fatigue point of the spoke’s j-bend is removed, straight pull hubs generally have worse spoke geometry as the flanges are much thicker than on j-bend hubs. This moves half of the drive side spokes inboard, which is a negative. For this, and for the pervasive availability of replacement j-bend spokes, we much prefer j-bend hubs and use them exclusively except in very special circumstances.
Okay so that wraps it up for Part 1 since this chapter is already way too long.