Summary: Perfect balance
The hub of 40 mm long is often considered the "standard" or "versatile" value on adult karts equipped with a 30 mm (x30, axle, Rotax, Kz, ok). Unlike very long (75-90mm) hubs that considerably rigidify the rear, or the very short (35mm) that fully freed the chassis, the 40 mm Offers neutral and healthy behavior, ideal for starting a setting session before refining.
- Technical specifications
| Feature |
Specification |
| Mark |
CRG (Genuine Parts) |
| Inner diameter (axle) |
30 mm |
| Total length |
40 mm |
| Material |
CNC machined aeronautical aluminum |
| Finishing |
Black anodized |
| Configuration |
Complete (with wheel mounting studs) |
| Compatibility |
Chassis CRG and standards with axle 30 mm |
🔧 Mounting tutorial: the rules of the art
Correct mounting avoids unexpected vibrations and loosenings.
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Cleaning the axle: Use a brake cleaner and clean cloth to remove any trace of gum, grease or oxidation on the hub range. A clean axle is guarantor of a hub that does not slide.
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Checking the key: Make sure the clock on the axle is not damaged. The hub must slide freely to the desired position.
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Progressive clamping:
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Position the hub.
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Tighten the bolts alternately (cross or up / down) to ensure uniform pressure on the perimeter of the axle.
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Attention to the couple: Aluminum is a soft metal. Excessive tightening will not better block the hub, but will mark the axle, making the future settings of painful width.
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Final verification: Check the absence of axial game. If the hub moves while the screws are tight, check the condition of your axle or the key.
💡 Michel's trick
"The 40 mm is my favorite starting point. The trick: If you change a rear lane width, always do it symmetrically (the same spacing on each side). If you feel that your kart is 'bizarre' with turn input, check that your hubs are tight at the same distance from the edge of the axle. My Pro Council: To prevent your hub screws from loosening with motor vibrations, always check the tightening once the engine is hot during your first output. Aluminum expands differently from the steel of the axle, which can sometimes relax the tension. "
❓ FAQ SEO (Frequently Asked Questions)
Q: What is the difference between a 40mm hub and a 75mm?
A: The 75mm brings more rigidity to the rear train, which can help load the chassis in case of lack of grip. The 40mm offers more flexibility, which is preferable on very adherent tracks to prevent kart from 'jumping' into curve.
Q: Is this hub compatible with a 50mm axle?
A: No, this hub is strictly reserved for axles of 30 mm. For a 50 mm axle, you must use 50 mm diameter hubs.
Q: My wheel studs seem worn, can I change them?
A: Yes, although the hub is sold "complete", the studs are wear parts. If they are twisted or the thread is damaged, change them immediately to avoid losing a wheel on the track.