Samuel, kinda a hot topic latley. My opinion is that due to minor "flaws" in drill bit sizes, the best thing is to use a set of calipers and measure your tube compared to the drill bit. I have even been known to make a "test hole" if I want to be really fussy.
A 35/64" bit is 13.891mm (or should be) so the 14mm should be ok, but it depends if your hole drilled runs high or low based on drill run out, bit size ect..
Damn, I just ordered one of these kits and now I have to go find a larger bit too! I only go up to 13mm in my large metric set. Dangit! I already have to find that monster bit for the Gent. I bought last week! So far everywhere I look they want twice as much as CSUSA for anything even close. [
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