BESNIN Adjustable Bike Stem 0-90 Degree 31.8 or 25.4x60/80/93/100mm, Adjustable MTB Stem Mountain Bike Handlebar Stem for Bicycle, Road Bike, MTB, BMX, Cycling

I bought this conversion unit to enable me to sit in a more upright position whilst riding on the road. I chose the 80mm variant as my original stem was 85mm, so this brought the handlebars a little closer to me before using the upward rotating function to raise the handlebar height as well as shortening the reach distance even further.The build quality of the item appears to be very good and inspires confidence, the rotating part of the mechanism relies on a toothed typed system to maintain a solid lock when adjusting the many different angle options available. When adjusted properly the entire headset feels solid with no play in the system.However there is one thing you will need to be aware of, and this unexpectedly caught me out, turning what should've been a 30min job into a few hours of assembling/disassembling the headset, until I eventually got everything working as intended. The centre bolt that screws into the star fangled nut in the fork section is very long and is not threaded throughout its entire length, which can hinder the ability to fully tighten down the stem without introducing a couple of millimeters of play in the fork. I was able to over come this by adding a 5mm stem spacer, which raised the new stem enough to negate the lack of thread on the centre bolt. This allowed me to tighten the stem enough to pull up the fork and remove the play that caused a rocking effect when the front brakes were applied whilst pushing the bike forwards.This may not be the case for every bike, as a lot will depend on the position of the star fangled nut within the fork. If its lower down the fork it will probably allow the fork to be pulled up enough to avoid any play, but if its higher up the fork tube, then it may need to be carefully knocked further down the tube. Alternatively a fully threaded centre bolt or stem spacer will be needed, as was the case in my installation. Apart from this potential issue the item is very sturdy and shouldn't be too difficult for the average biker to fit.So to conclude, this item should provide any buyer with a full range of adjustments from 90-180 degrees, shortening the distance between rider and handlebars, as well as increasing the overall height of the handlebars. This should result in a much more comfortable and enjoyable ride.

This is a solid piece of kit that have I fitted to my Dawes Super Galaxy touring bike in order to reduce the reach and give me a more upright position. For "solid" read "quite heavy", so I probably wouldn't go for this if bike weight is real consideration. There is no doubt that it has made a big difference to the comfort of my riding position, but I have one real issue. Rather than the top of the stem being finished off with a screwed down water-tight metal cap they have gone for a plastic plug. The problem is that the plug has already fallen off leaving a hole into which rainwater can now fall and over time lead to rust. So, if you do go for this product then make sure you use some kind of super-glue to fix the cap in place. This is a real shame because, without this flaw, I'd have given it 4.5 - 5*.

Unfortunately I had to send it back because it didn’t fit the rock bloc system on my trek MTB

The installation was obvious and straightforward... but some users might appreciate instructions.

it makes to use my bike in an ergonomic way.

Brilliant, did the job excellently compared to a previous one that was terrible! Stays in place and good range for adjustments.