Review on 31.8Mm 45Mm Wake Mountain Bike Stem | Aluminum Alloy, Black Blue Gold Red | Fit Most Bicycle, Road Bike, MTB, BMX & Fixie Gear Cycling by Gent Dobson

I got this to shorten the cockpit of my son's 20" MTB. Does exactly what I needed and no issues with the screws or clamp force. Since he's not doing drops or any serious trail riding yet, this is was perfect to get him the shorter reach he needed to improve his comfort and bring his confidence back up to where it was on the bike he's outgrown.The two most apparent downsides with this style stem are -1. Shorter clamping area on the steerer tube compared to all the stems I have used. You will likely need to buy additional spacers to install it properly ($7-$$ on Best Buy). I needed 8mm to get the proper top cap spacing; your needs may vary.2. The typical cutout on the front isn't there, so using the handlebar's centering image is much harder as the stem's clamp covers all but the outer hash marks.I didn't weigh it, but is seems to be about the same as his factory 70mm 7° stem. That's not a complaint, just an observation.Overall, definitely a good value if you want to try a shorter stem.