Not quite true. Check out this excellent article from revzilla on the difference between bias and radial ply:
Really, it all comes down to your tire application - what do you intend to use it for? Personally, I use my motorcycle (a 200NS) for commuting and touring. I have NEVER brought it to a race track and am not interested in taking low angled corners. So, for me at least, a set of bias ply tires make more sense. The stiffer sidewall also performs better (than radials) under heavy loads and are probably slightly more resistant to (sidewall) punctures - thus, increasing touring / commuting reliability.



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