Search the number - where is it written on the frame?
The next time you wash your bike, take a look at the frame. If it's made of carbon, look for a number. On my Whistle AXR, the number is 5. Large, next to the logo, with mountains and a little book drawn beside it.
I worked in IT on structured cabling projects. In networking, CAT 5 was the type of UTP cable that carried data quickly. The telephone ones were only CAT 3.
I saw 5 on the bike and wondered what it was? Especially since the label directs you to read the EN17406 standard.
What can you do with a CAT 5 carbon frame bike?
CAT 5 defines how strong the carbon in the frame is built and what you can do with it
The standard behind the number is called EN 17406. It's the European classification for usage. It has six classes, from city to racing bike. Class 5 is the gravity class. It includes extreme jumps or downhill on rough terrain at over 40 km/h. The jump height in the classification exceeds 120 cm. Examples: downhill, dirt jump, freeride.
A frame classified as CAT 5 means that the manufacturer has declared the bike for that use. If you use it beyond its class, the responsibility is yours. The bike is used for what it was made for and not beyond what it can handle.
The six classes
CAT 1. City
Asphalt. Small drops, under 15 cm. Commuting, leisure.
CAT 2. Gravel
CAT 1 + Gravel, dirt road, moderate slopes. Still under 15 cm. You can lose contact with the ground briefly.
CAT 3. Mountain trails
CAT 1 + CAT 2 + Roots, rocks, trails that require some skills. Jumps and drops under 60 cm. This is where cross-country and marathon sit.
CAT 4. All-mountain
CAT 1 + CAT 2 + CAT 3 + Technical descents under 40 km/h. Jumps under 120 cm. The bike is checked often.
CAT 5. Gravity
CAT 1 + CAT 2 + CAT 3 + CAT 4 + Extreme jumps over 120 cm, downhill runs through rock gardens and roots, at over 40 km/h or any combinations of these. Downhill, dirt jump, freeride. This is where Whistle placed the CAT 5 carbon on the AXR models.
It looks like the label on the 8.7, doesn't it? Or is it identical?
It seems that manufacturers are indeed required to display the frame category.
So before you push a bike on a more difficult trail, or when choosing a rental bike model for bike parks, check the frame for its CAT.
CAT 6. Racing bike
Race speed, over 50 km/h, on asphalt. Small drops again. Sprint, time trial, triathlon. Another discipline.
Class 6 is for people who race on the road.
What do you want to do with it?
To work and back, on asphalt, a CAT 1 or CAT 2 is enough. A CAT 5 doesn't help you more at the traffic light but how comfortable is a full suspension in the city, right?
Trail, roots, rocks, small jumps: CAT 3.
Enduro with drops up to about a meter: CAT 4. Under 120 cm and under 40 km/h on the technical descent.
Bike park, big drops, speed on rocks and roots: CAT 5. This is where Whistle placed the AXR carbon. With protections, and keeping an eye on the frame after a tough day. It makes sense even on an electric bike with an 800 Wh battery in the belly.
Race road: class 6. Another bike.
Tell us your number, what CAT do you have?
I took a picture of the label. Year 2026, AXR model, class 5, carbon.
What CAT does your bike have?
If you plan to get one in the near future, check what CAT it is.
Where can I get a CAT5 bike?
Did you know that any model from Whistle is CAT5?
We still have them in stock, why hesitate?
I tested it in Poiana on all trails, both uphill and downhill, in Azuga and on red and blue, and climbed all the way up to the peaks to Sinaia plus descents on those beasts. And in Brava Paul and at Șugaș during the competition.
Alex is testing it in Maribor this week.
What are you waiting for?
Whistle Bikes with Avinox M2 and M2S in stock at BIKEVERSE - order today, receive it tomorrow
The bike models available today for delivery tomorrow
If it's 4 or lower, you have a bike declared for a different game.
I know it’s not said CAT in this industry but I like how it sounds, the analogy with CAT 5 cables that are still powerful, despite the WiFi invasion, and carry many Gbps full duplex.
And after all, it really is a category.
To see how lucky some are: it's raining here now and I’m glad I was in Azuga on Sunday.
Look at how the weather is this week in Maribor:
Maribor trails
Maribor trails map:
Maribor laundry:
Queue of cyclists in Maribor:
And I didn't meet anyone in Azuga during the 5 descents I made...
Not you let me pass by you, not you queue at the gondola...
And the weather was superb:
