Originally Posted by
Callador
A wider grip does have a slightly reduced ROM, but changing your technique shifted the load of the weight around a little. You have been benching with a fairly narrow grip, so your muscles have adapted to that. Moving to a wider grip shifts some of the load off the triceps and onto other muscles instead. Since you haven't tried it in the past, you will most likely move less weight.
Some lifters never use the max legal grip, especially raw. Even after training with a wide grip, they still can't bench as much as they can with a closer one (see Konstantinovs). Others prefer the wide grip, it really depends on how you are built. As you mentioned too, some have shoulder problems from going really wide. I use a variety of grips, but stick to the narrower ones unless I am pressing off boards or in my bench shirt.
Stick with your SS grip right now, but after you finish it, you can start to experiment with closer or wider grips and see how you like them.