Hello,
There currently isn't a way to set the clip length. That said - some rules result in longer clips than others. For example, If you had a camera viewing your driveway and set one rule with a boundary at the edge of your driveway and one rule with a region of the entire driveway, the boundary rule will generate a short clip of a person or object crossing the boundary while the region will capture the entire event of the person walking across the driveway.
If all the clips you are syncing are 2 minutes long, then it sounds like you're syncing the files directly from the video location which is not recommended. these files are set in 2 minute increments and do not correlate to the clips you see for your rules in Sighthound Video. These files are the source video that are used to create the clips for your rules so that there aren't duplicate video files for your rules. We strongly recommend not syncing or modifying these files in any way as doing so can result in data loss in the Sighthound Video software. If you wish to sync video from your rules we recommend using the "Export to local folder" feature -
https://www.sighthound.com/support/export-local-folderRegards,
-Devin