After a small bump at the weekend, my right Tiagra 4600 10-speed shifter is not 'quite right'. It still works but is sticking out to the right. It is just the brake lever bit (not the change up lever or the whole unit). Feels like a retaining spring has gone or a little bit has snapped inside. Anyone got any experience/advice? Is it worth deconstructing or are they tricky things? Just buy another?!