GL Core Spring
- Spring Normal Tension
is in production and will ship as soon as it is back in stock.
The spring also control the shaft spins, Harder tension will pull the shaft on the Core and reducing spinning.
For more info about GL core you can this article.
Using the Hard spring tension will pull the shaft on the Core reducing spinning but it will create more friction, it is recommended to apply grease for plastic on the Core surface to reduce friction.