Originally Posted by AnthonyG

I have the Shimano ST-R600 levers on my bike. To me they are IDENTICAL to Ultegra levers of the same era except that the shims are already in place to reduce the brake throw as standard. The sideways throw to change gears is identical to the Tiagra levers. From that 9 speed era the Tigra, 105, Ultegra and R600 levers ALL had an IDENTICAL working mechanism. There were only changes to the body/mount but the working parts were all the same.

Originally Posted by AnthonyG

Now I have a confession to make. I can RANT for ages on the fit of bicycles for small people and I'm not particularly complementary of the RUBBISH that bike manufacturers foist on small riders. Your issue is likely to be somewhere else in the fit, namely you have been positioned too far forward in relation to the Bottom Bracket which places TOO much weight on your hands/shoulders which makes it VERY difficult to change gears/brake when your also trying to hold up your weight. Larger riders don't have so much weight proportionally on there hands/shoulders as small riders are forced to endure and since you have never experienced anything else you don't know anything else,.