Unless you are female, and very attractive, for the love of God, pity the rest of us, and put on a shirt with sleeves.

Ruling out the male portion of the population, and 75% of the female portion, the odds are high, you'll look better with sleeves.

Then add in that, sleeveless is not necessarily cooler, is against USCF rules,and increases crash damage, the answer is to just say no.

Unless you look like this: