Using a 36-1 trigger wheel with a GT101 is often borderline unless your wheel is very large diameter. The gaps between teeth need to be quite large (~10mm) and the teeth need to be about 5mm long to get a good reliable trigger from that sensor. Although the Gt101 is still a popular sensor for crank triggers and seems quite dependable, it does have some negitives such as the tooth/gap size required and the response time is a bit slow for high RPM use.
I generally like to lean towards a VR sensor on high tooth count wheels for better accuracy.