This idea that a heavier bow helps make a bigger sound is something that I'm inclined less and less to agree with. This idea seems to keep resurfacing - recently, in a discussion of Prochownik bows (which I own three). I have to say I agree with Prochownik's idea that a heavier bow does more to tire you out (and risk injury) that it does to add to your sound. My main bow is a 127g Prochownik Sartory model french bow. I get a huge, warm, well defined sound and it is the lightest french bow I've ever owned. If I do need more sound, I can always relax my arm weight more, play a little closer to the bridge and/or use a faster bow stroke. I almost never get a sore bow grip anymore, even after playing 30 bars of fff tremolo in Tchaikovsky, which leaves me relaxed enough to get more sound with the aforementioned methods. I mean, honestly, what are a few measley grams of bow weight going to do for you that relaxing your 15-20+ POUNDS of arm weight won't (even considering that you won't manage to get all of that transfered to the string)? The other issue I have with heavier bows is that they usually don't respond as quickly, so articulation can be a real issue. What's the use in having all that extra weight if you can't get the notes in a tricky rapid passage to speak? I suppose a bow that is really extra light could have some dissadvantages, but I still contend a medium light bow is capable of being just as loud (or more) because the player can more easily direct their own weight and energy to the bass rather than lugging the extra lumber around. In short, I feel the more relaxed and rested I feel, the more I am able to get a big sound out of the bass. Lugging a heavy bow around interferes with that IMO.