Welcome to the forums Carlos.. Unfortunetly the Volcano S30 uses a Sh. 18 which has an internal one way bearing so you would need to get the one way bearing for the SH. 18. The HPI or the Traxxas will not work..

I sell them on my site.. Link is http://urchobby.com/proddetail.php?prod=TS005

if you need any other help you can email me at [email protected] be glad to help you out..

Again Welcome to the forums. Kurt