I would think it would be technically tricky- if the rear is spaced for a track wheel then it will be 120mm OLN, whereas a geared wheel will be 130mm, so finding a hub/casette combination that will fit would not be easy.
Also I do not think that the Flyer frame has a mech hanger?
In conclusion- yes you can, but it will be difficult and expensive.
You could come to the drinks, get to know people, and then borrow a geared bike, or on the other hand make your single-speed Flyer live up to its name on the Tri course?
I would think it would be technically tricky- if the rear is spaced for a track wheel then it will be 120mm OLN, whereas a geared wheel will be 130mm, so finding a hub/casette combination that will fit would not be easy.
Also I do not think that the Flyer frame has a mech hanger?
In conclusion- yes you can, but it will be difficult and expensive.
You could come to the drinks, get to know people, and then borrow a geared bike, or on the other hand make your single-speed Flyer live up to its name on the Tri course?