Well, from all the reliable sources i can gather, theres
actually almost no outside factors that will affect the size of
your penis.
What is true about cycling is theres more likely a chance that one
might get testicular cancer. The size was not affected at
all.
The only way for what you said to be true is you had tried it and
now your buddy is hidden under your bush. 
And if this is what happened, you might be the first man to
experience a small penis due to cycling
