Since 2015 Cannondale has released BB30A and PressFit30A or PF30A. Originally on the Synapse and Slice, the standards have now been rolled out across most of the road and mountain platforms.

Let's slap a BB30 sticker on it!

Before we get started, there is a good chance your Cannondale frame has a BB30 logo on the down tube. Cannondale is the company that invented the BB30 standard in the early 2000s and they printed a gazillion stickers that they are still trying to get rid of today.

Ignore it. There is no guarantee your frame is actually a BB30 frame.

What's with the A?

The A in BB30A and PF30A stands for Asymmetric. The bottom bracket shell is made 5mm wider on the non-drive side only. According to Cannondale it makes the system wider and stiffer. Other benefits include making shorter seat stays and helping with the Ai, Cannondale's off-center rear triangle and wheel system.


  • Cannondale loves putting BB30 stickers on frames that are not BB30 or even fit a BB30 crank set. Like on this PressFit30 Asymmetric SuperSix. We all have our quirks.


BB30A vs PF30A

One new standard is great, two is better! in 2015 the Synapse started using BB30A (bearings pressed direct in the frame), the Slice TT bike started using PF30A (bearings pressed in a cup, then pressed into the frame).

The width dimensions are the same, only the diameter of the frame opening is different: 42 vs 46mm. Typically a BB30 shell is made of aluminum, where a PF30 shell can be made out of all carbon.

We need more standards!!

As if two new standards, exclusive to Cannondale was not enough, the guys in Connecticut decided to add 2 more.

In 2017 the new SuperX cyclo cross bike came out with BB30A83: same as BB30A except at 83mm width instead of 73mm. You will also find this standard on the Topstone Carbon frames.

In 2018 the Scalpel Si cross country race bike has PF30Ai. Same as PF30, only wider by 10mm. The A stands for Asymmetric Integration in this case, this refers to the fact that the rear wheel hub and drive train are off-center in the frame. But the bottom bracket is symmetrical.

Since the entire rear of the frame is off-center, we managed to fit a Shimano crank set on these frames, but the arms always seem to hit the chain stay. To make things more confusing: the Cannondale Factory Racing team uses that exact setup: Scalpel plus XTR crank set. More research required.

Why, why, whyyyyyyy?

The result of all this innovation is that it is virtually impossible to fit an aftermarket crank set on a Cannondale frame. If you want to transfer your power meter from another bike: tough luck!

Kogel Bearings and other bottom bracket manufacturers have designed conversion bottom brackets for the most common asymmetric frames. A standard that is only used on one model of CX frame does not sell in enough volume to justify the tooling and production cost for aftermarket products. Sorry Johnny, no Shimano or Quark crank set for you.

Cannondale is a company that strongly believes in system integration. They will design every part of the bike to what they think is the best fit. From a suspension fork with only one leg to wheels that are purposely built with the rim off-center. Cannondale produces crank sets and all these confusing bottom bracket standards forcing customers to use theirs over a third-party solution.

What's the standard of my frame?

I have tried to make a comprehensive list of all Cannondale frames that use the asymmetric standards below. I think it is accurate, but if you see any mistakes or updates, feel free to bring them to my attention with the contact button at the left bottom of your screen.

BB30A (73mm width, 42mm Inner Diameter)

  • Synapse 2015 and later
  • Caad12
  • Slate


PF30A (73mm width for road bikes, 78mm width for MTB, 46mm Inner Diameter)

  • Slice 2015 and later
  • SuperSix Evo HiMod 2016 and later
  • FSi


BB30A83 (road edition)

  • SuperX 2017


PF30Ai (MTB edition)

  • Scalpel Si