Tell him that chicks don't like training wheels.
And make sure if you are gonna do a conversion, to do it right. No sense in ruining a good quad, even if you are making a trike, unless you do it right. Otherwise it's just a POS.
This is my trike. There are many like it but this one is mine. My trike is my best friend, and it is my life. I must master it as I must master myself. My trike without me is useless. Without my trike, I am useless. I must ride my trike true. My trike and I know that what counts is not the amount of miles we ride, but the time we ride together. My trike is human in it's own ways, therefore I will learn it as my brother. I will learn it's weaknesses, it's strengths, it's parts, and it's soul.