Promax came out swinging this year putting some serious effort into updating its line of drivetrain-related components. The latest additions not only looks better but also bring additional functionality, all in the hopes of helping you go faster!
In this article, we’ll spotlight each new Promax product while also explaining how they integrate with one another.
- Promax CK-1 (carbon crank)
- Promax HF-3 (Alu crank)
- Promax Spider
- Promax Direct Drive Chainring
CK-1
Promax is no stranger to producing BMX Race cranks, as the previous HF-2 succeeded on all levels and even won a few world titles. The cranks of the past were extremely capable, but the modest price tag led people to believe they were mid-tier. With the addition of the CK-1, Promax is turning that narrative on its head and entering the ultra-premium relm of race cranks.
The CK-1 is Promax’s top-of-the-line carbon crank offering. The race-ready carbon design maximizes strength while minimizing weight. Coming in at just 448g for a 175mm crankset, the CK-1s are practically half the weight of traditional aluminum cranks!
Despite the lightweight, the CK-1s are built tough as the carbon arms spin on a beefy 30mm chromoly spindle. This oversized spindle aids in increasing stiffness and power transfer. The 30mm spindle also utilizes a straight-thru Bottom Bracket style, whereas other 30mm crank options require a specialty tapered 30mm BB.
Why that matters?
The bearings used in a straight thru 30mm BBs are far more common as they're used in other parts such as race hubs. If you ever find yourself in a pinch at a race, you’ll have a better chance of finding the correct BB size for your cranks.
While the CK-1 is the first BMX-specific carbon crank released from Promax, prototypes of this crank have been in development for multiple years. A lot of time went into the development process of the CK-1 to ensure they're race-ready on day one.
We even had a pre-release set of our own at the shop that a few of our factory riders rode to collect honest race feedback and durability testing. All this to say, the CK-1s are a refined piece of BMX Racing technology, ready to help you reach your best!
HF-3
Following the success of the HF-2, Promax decided to update their best-selling aluminum crank as well. As the name suggests, the HF-3 is the bigger and better version of the long-lived HF-2.
Like the CK-1, the HF-3 also receives the same oversized 30mm chromoly spindle. This also utilizes the same straight thru 30mm BB we talked about with the CK-1. Increased rigidity and responsiveness are two things you can expect from this crank while maintaining the traditional hollow-forged aluminum build.
The HF-3 also features a removable spider allowing the use of direct mount chainrings. This is a new feature for the HF-3 and counts as another small upgrade over the HF-2. We will talk more about the benefits of a direct drive system later on, but in short, this is another method for saving even more weight with the HF-3!
Aside from the oversized spindle and direct mount chainring flexibility, the HF-3 carries over most of what made the HF-2 so popular. It's a high-quality 2-piece race crank that packs most of what you'd expect from a crank within this price range. We believe the HF-3 is perfect for those who aren't quite ready to go full carbon but still interested in receiving top-tier performance.
Direct Mount Chainring
To pair with the CK-1 and HF-3’s direct mount capability, Promax also released their own direct mount chainring. Machined from high-end 7000 series aluminum, the Direct Mount chainrings are lightweight yet capable of handling the torque and stress of modern BMX racing. At the time of writing this article, the Promax Direct Mount Chainring is available in sizes ranging from 42t up to 47t with more sizes to follow soon!
Seeing as 4-bolt chainrings have dominated the market for so long, some may wonder what’s the point of direct mount chainrings. The most prominent reason has to be the weight savings. Direct mount chainrings eliminate the need for a spider and chainrings bolts. That adds up to a significant weight savings which you will see later in this post.
In a sport where racers are counting grams and swapping Chromoly bolts for Titanium, going direct mount only makes sense. And if you’re purchasing a set of CK-1s to save weight, why not go all out and maximize the savings with a direct mount drive system?
Direct Mount Spider Adaptor
The CK-1 out of the box come ready to accept direct mount chainrings. While direct mount chainrings are a great way to save weight, they're not commonly found in race shops. To help you feel less restricted, Promax offers a Direct Mount Spider adaptor allowing you to run standard 4-bolt 104 BCD chainrings on your CK-1 cranks. We really like that Promax opted for an aluminum spider as carbon spiders can get a bit finicky. This material choice keeps installation simple and hassle free.
But as mentioned before, the HF-3 includes it's own removable spider (shown above) so no need for the additional purchase. However, Promax states that these two spiders are not interchangeable. The Adaptor built for the CK-1 will not work with the HF-3 and vice versa.
Customization Like Never Before
Promax is slowly creating an entire drivetrain ecosystem that gives you more options and flexibility than ever seen before from a brand. No matter the crank you choose, you can customize them to suit your specific needs.
Looking for the absolute lightest drivetrain?
Looking for a traditional setup?
Weight savings on a budget?
The most flexible Carbon crank choice?
But for a better visual, the chart below outlines the weight in grams of the various configurations possible. You’ll notice significant weight savings as you move from the previous HF-2 over to the CK-1!
175mm crank weights in Grams
| Notes | Configuration | CK-1 | HF-3 | HF-2 |
| Using 45t Promax Ring | 4-bolt | 660 | 962 | 1043 |
| Using 45t Promax Ring | Direct Mount | 567 | 894 | N/A |
| No Ring | Arms/Spindle/Bolts | 448 | 775 | 831 |
| No Ring | Arms/Spindle/Bolts/Spider | 520 | 820 | 901 |
As you can see, there are multiple ways to mix and match these offerings from Promax. And honestly who doesn't love toying around with their setup?!
We have yet to see another line of drivetrain components offer this much compatibility. Typically, you find a crank you like and you're forced to run however it comes (spider, no spider, etc.) We like what Promax is doing here and hope more brands follow suit in the near future.
Images and text by - Jonnie Vance
