Access for every registered user to all events

[GBayerl]

Hi together,
I would like to use JEvents to manage bikerides for registered users. It means, you (user 1) can go to the calendar and add an event, when you want to go for a bike ride. If someone else (user 2) see this event, he should be able to add his name to the description field of this event created by user1.
In my claendar only the creator and the administrators are able to edit published events. Is there a possibility to open the permissions, that every registered user can edit such events or do someone konows a component which will support my problem?

Thanks in advance
Regards
Günther