My brother has a sunlite 95mm adjustable stem Sunlite- Products that has started to make some creaky/squeaky noises.
It hasn't loosened up, but it doesn't inspire confidence.
His riding is on roads of varying quality, but pretty flat. No steep hills, or rough trails.
How can we stop the noise?
thanks.

Installed the same stem recently on a customer's bike, and as long as it's tightened properly, after it's adjusted, there should be no movement to cause any noise.
Cheers

Best: get a non-adjustable stem that matches the preferred setting.

Kludge: epoxy.

Take it apart, grease all mating surfaces including the stem pivot area, handlebar/steerer clamp and bolt threads. Bolt it all together and it should be squeak free.

I may be reading into this, but when you say "tightened properly" are you referring to a torque setting or just making sure all bolts are snug and secure

This is what I was thinking. Admit to being a little unsure as to what type grease might be best for this fix.
suggestions?

Most greases will do the job. If you have some marine grease it tends to hold up to moisture well, bearing grease, any of the specialised bike greases will also work well. Anything you might have laying around the house already will probably be fine since the lubrication demands are low. You just need something that stays put for awhile.

When you tighten the adjustment piece, wiggle the bars up and down a bit to make sure you're getting the teeth that hold the adjustment in place to fully engage.

I tighten bolts snug and secure, haven't used a torque wrench on a cycle in many years. Beginner mechanics probably should use a torque wrench.

non adjustable stems have less potential places to squeak.


my no where as cheap as 'sunlite', ITM CNC adjustable angle stem has some creaks, it is just a feature.