I'm guessing BG66M, due to the thinner and more 'naturally' braided gut? The NBGs feel a but stiff for their diameter/size to me. Besides, the BG66M is specified to have a soft feeling on impact, just like the BG65; perfect!
Well the new BG66M is 0.65mm, the thinnest Yonex thus far. You can imagine the repulsion.... It's also the only Yonex repulsion type string with a soft feel.
Thanks for all the replys. But which one is more durable? I know that the new bg66 is thin... so does that mean its stronger?
Thinner = breaks faster. NBG98 is supposed to have surprising durability for a 0.66 string because of the coating, so if you want power but more durability, you could go for that. You won't be disappointed by both strings.
The thinner the string, the easier it is to break, simple physics. But according to Yonex's marketing, there is something new in the BG66M, which according to them makes it slightly more durable than even BG80, but maybe not as durable as the BG65. The NBG98 is marketed as having the same durability, although it is 0.01mm thicker.
I've never understood the hard vs. soft feeling aspect of strings. Isn't hard feeling simply a product of a higher tension?
Well I'm currently using both the BG80 (hard feeling) and BG65 (soft feeling) and I can tell that by stringing BG65 at around 2lbs higher in tension, they feel about the same. I'mnt sure but I think it has something to do with the vectran Yonex integrates into the BG80 which makes them feel less stretchy and have a harder impact feel. I personally prefer BG65, but use BG80 on my "more fragile" (meaning less Yonex warrantied tension) racquets and doubles racquets where breakage is more likely to happen. IMHO this is the most useful application of the hardness rating of Yonex strings, to me at least. Hope I don't break another racquet that is!
Hard feeling - the stringbed doesn't flex as much and it feels stiffer, less bouncy. Sort of like higher tension, but the pitch isn't higher. It's hard to explain....try to string with BG70 PRO and then BG65 at the same tension and you feel that BG65 feels softer and bouncier compared to the BG70.