Is your chain rattling and do you feel as though it’s trying to shift to a different sprocket? With MicroAdjust, you can fine-tune the rear derailleur of your SRAM AXS groupset using the shift levers, even whilst riding. We’ll show you how to do it, step by step.
You’re pedalling, but the chain isn’t running smoothly on the sprocket. It rattles and feels as though it’s about to jump to the next one. You shift up and back again, but the problem persists. Adjust the derailleur? You might have preferred to leave that to the bike shop until now. With SRAM AXS derailleurs, you can make a small adjustment yourself, without any tools or screws.
The rear derailleur guides the chain from one sprocket to the next. If it is slightly misaligned, the chain may rattle on a sprocket. It may also take a moment for the chain to settle onto the next sprocket when changing gears. MicroAdjust is designed to address such minor misalignments: This function shifts the derailleur a tiny bit to the side. If, on the other hand, the chain suddenly jumps over the teeth whilst you’re pedalling, this could be down to wear and tear. This cannot be easily fixed with MicroAdjust. Before you try out the function for the first time, stop in a safe place and take your time to locate the buttons.
First, find the right button
Look at the inside of the shifter. That’s where the small AXS button is located. It’s important for fine-tuning. On some newer Red and Force shift levers, there is also a button further up on the inside of the lever body. That is the ‘Bonus’ button, not the AXS button for this lever. TOUR describes the additional buttons in the Review of the SRAM Red AXS.
How MicroAdjust works
- Press and hold the AXS button on the gear lever.
- Whilst holding it down, press the gear lever once.
- Let go of the pedals and, whilst pedalling, check whether the chain is now running more quietly and whether the adjacent gears are shifting smoothly.
Which side you use determines the direction:
- When turned to the left, the rear derailleur moves inwards, towards the larger sprockets. These are positioned closer to the spokes.
- On the right, the rear derailleur moves outwards, towards the smaller sprockets.
You don’t need to know straight away which direction is the right one. Try one adjustment and see how it sounds. Is it better? If so, you can make another adjustment in the same direction if necessary. If it sounds worse, go back one step. This way, you can feel your way forward rather than making a drastic adjustment on a hunch. Depending on the AXS rear derailleur, one step is 0.2 or 0.25 millimetres, according to SRAM.
If a gear change occurs instead of fine-tuning...
... then you’ve probably triggered a normal gear change, not a fine adjustment. Check that you’ve actually pressed the AXS button on the inside of the shifter. The order is important: first hold down the small AXS button, and only then operate the shifter. If you just tap the button briefly or release it before operating the shifter, the AXS will shift up a gear as usual. It is therefore crucial that the AXS button is already pressed and remains pressed whilst you operate the shifter.
When MicroAdjust doesn’t help
MicroAdjust only adjusts the position of the rear derailleur. The adjustment affects all sprockets, not just the gear that is currently rattling. Is the chain skipping? Are several gears not working properly despite careful adjustment? Or has the rear derailleur taken a knock? If so, stop. The problem may lie elsewhere, such as a bent derailleur hanger or a damaged component. TOUR shows in the General guide to adjusting road bike gears, what other causes there are.
The key combination works when stationary and whilst cycling. If you’re not familiar with it yet, practise it first whilst stationary and then test it out on a quiet stretch of road. Never reach for the derailleur whilst cycling, and do not use the smartphone app whilst cycling.
Sandra Schuberth
Editor
