return from somebody who have tried needed.I have not tried with this spider, but on normal 104bcd crankset a 30T chainring is minimum. It has threads in the chainring instead of using bolt with counterpart, to get it to fit.
I find that chain is very close to the speeder, i doubt that it fit with 2 teeth less. but may be with few adaptation ?. the other problem is chain position in regards of swing arms, with the E10 i needed to install protection to avoid that chain eat the swing arm. Most space available on the CEF50