Rim Roundness & Flatness Testing: Ensuring Precision and Stability

When it comes to bike rims, achieving perfect roundness and flatness might not always be possible. However, it's critical to ensure that these factors fall within specific tolerances to guarantee a consistent wheel-building experience and stability at high speeds. Even small deviations can affect performance, so we take every step to ensure your rims are up to standard.

Test Standard

Tolerance range: within 0.3mm

Test Facility & Equipment

We use specially designed roundness and flatness test jigs that measure both radial and lateral run-outs with precision up to 0.01mm. These devices rotate the rim, automatically recording readings to ensure accuracy and consistency.

Rotation Speed	Precision	Test Sides
600rpm	0.01mm	Both rim sides

Test Method

Our roundness and flatness tests follow a precise method, with testing conducted on two separate rigs. While the equipment and setup are different, the testing process is the same for both.

Step 1: Position and clamp the rim securely onto the testing rig.
Step 2: Tare the digital scale and bring the cylindrical tips to the edge of the rim.
Step 3: Press the “rotate” button to start the rim’s controlled rotation.
Step 4: As the rim rotates, lateral and radial movements are measured and recorded automatically.
Step 5: Flip the rim and repeat the process for the opposite side.

Sample Test Report

Example Profile

Model	Size	Width	Depth	Weight (Stated)	Measured Weight
EN32-23	29er (622-32)	32/39mm	22/23mm	460g	459g

Test Results

Roundness		Flatness
Min	Max	Min	Max
0.21	0.27	0.25	0.3
0.06mm deviation		0.05mm deviation

In this sample test, the rim's roundness and flatness fall within the specified tolerance range, ensuring it meets the strict performance standards on the road.

About Us: Our Story; Our Team

What We Offer: OEM vs ODM Service; Open Mold Products; R&D and Technology; Quality Control

Get In Touch: Floor 3, No 19 Baihuyan Road, Xiamen, Fujian 36102, China

Email: koko@ntpcomposites.com
Drop a call: 0086 137 9925 1201
What's app: 0086 156 5978 9571

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NexusTech Prime (NTP) Composites

Established in 2013 initially as an OEM carbon rim contract manuafacturer, NTP composites has grown steadily to be a full-service OEM and ODM service provider, with brilliant quality control, proficient engineering capability, and excellent customer service.

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