SRAM TT900 / TT500 Shifter Spring Kit - Rear

I recommend this product

Sram tt shifters have a habit of getting through the spring mechanism so that the indexing becomes non-existent when the springs weaken and break. These springs should be considered a consumable item. Despite failing to find guidance on the internet on how to replace these springs it actually turned out to be a simple five minute job. All you need is an allen key to remove the retaining cap and a penknife to lever out the old springs. This can be done with the shifter in situ.