Thompson Elite - 100mm, 15 degree rise This stem is marketed as a solid piece of cross country equipment. It is advertised as stiff and light. The most notable thing about this stem is the mechanism it uses to clamp onto the steerer tube. It has two bolts that pull from either side to bring wedges, a la Syncros style, into contact with the steerer. The difference here is that those wedges clamp the stem a full 180 degrees around the steerer tube. This makes for a very confidence inspiring connection. The handle bar attaches to the stem via a four bolt face plate with a fairly wide contact area. All hardware on the stem is 4mm and all pieces are interchangeable. All components of the stem are CNC machined and the finish is impressive. It should be for $120. It is important to follow the directions included with the stem and adhere to the recommended torque values for the hardware. As all the bolts are 4mm it is easy to strip the heads out of them if they are done up too tight. One of the most impressive things I have noticed about this stem is that in over a year of using it on my main ride, nothing has come loose. All bolts have remained tight. What is more impressive is that numerous crashes have not moved the bar or off centred the stem. This is a welcome change from having to always break out the allan keys and straighten my stem after a crash. Now I can just get up and go, if I'm able. The Thompson stem is very stiff, I won't pretend to evaluate the stiffness on a scientific basis, but I will say that when you pull on the bar there does not seem to be any noticeable flex. The stiffness associated with this stem is a surprise for something that feels as light as it does. Overall the Thompson stem is a stiff, very reliable, heavy duty piece of equipment in a cross country package. It looks good and offers no trouble over the long run. The only negatives are that the bolt heads are weaker than they could be and shorter lengths of the stem are not readily available, although a full range of longer lengths are.
Race Face Downhill SYStem - 50mm, 10 degree rise I have a bike with a really long top tube. It didn't feel right with the stem I had intended to use on it so I though that a 50mm would do the trick. I picked up the Raceface Downhill SYStem Stem for about $ 130.00. Pretty steep, but I was assured that it was a solid product that was stiff and durable, and a definite upgrade from my Raceface Prodigy stem. Once installed on my bike it looked ugly, there were no smooth lines as on the other stems in this comparison. One unique thing about this stem is the "dovetail" method of clamping the stem to the steerer tube. One piece of the stem wraps around the back of the steerer, and clamps both the steerer and the stem extension or neck with two bolts. There is no welding on this stem. When installing this stem it was worthy of note that the finishing job and the machined tolerances were very good. The bolts that hold the dovetail portion of the stem are replaceable as are the pieces they thread into. - Great for hacks. The handle bar is secured to the stem with a two bolt removable face plate. Installation is fairly straight forward except that the dovetail design of this stem makes it really difficult to centre the stem with the front wheel. As you tighten the stem on the steerer, the stem will always pull to one side. This motion is not consistent and the stem can pull to either side when tightening. Aligning the stem was a big trial and error affair, as were any head set adjustments. On the plus side, once it was on properly it stayed put. As the handle bar pace plate was two bolt, I didn't know what to expect from it. The stem was rated for down hill and free ride use so I assumed it would have the durability required for such use. The handle bar clamp incorporated fittings on the face plate that are designed to centre the bar in the rear of the clamp, a nice feature. Right from the get go there was noticeable flex in the handle bar. The bolts had to be done up tighter than the recommended torque ratings to prevent the bar from slipping when bringing up the front end of the bike. This happened with two different, brand new handlebars used with this stem. Another problem was that half way through rides the stem would start to make small creaking sounds. This was a result of the face plate bolts working their way loose. They had to be tightened before every ride and usually once through a four to five hour ride. The Raceface Downhill SYStem stem is not an impressive piece of hardware. For the price of $ 130.00 there are a lot of better, more reliable stems on the market that will give a rider more confidence.
Raceface Diabolous - 50mm, 10 degree rise Flames, almost enough said. As an updated version of the Raceface SYStem, the Raceface Diabolous stem is designed to be a downhill freeride stem that offers several improvements over last years design. As a note of interest, last year's SYStem is still being offered this year. This stem offers a four bolt face plate design, normal steerer clamping mechanism and a boxy, BMX stem-like design. Installation is a breeze as everything is straight forward, and tolerances are good. All hardware is 5mm, although this stem lacks the replaceable threads of the other stem. This stem holds the steerer as all the others mentioned but the real standout is how this stem holds the bar. The four bolt face plate provides a nice wide clamping surface for the bar and integrated wedges in the face plate centre the bar at the rear of the stem clamp. This stem does not have to be done up very tight to start supporting the bar adequately. If torque recommendations are followed, you can be assured that your bar will not move. The stem looks very beefy compared to the other stems in this test, the Raceface Diabolous' weight also confirms this as it weighed the most. So far, everything has stayed tight on the stem, although it seemed like for the first couple of rides, things would loosen up somewhat, but after an initial settling period everything has stayed tight. This stem is a solid component and can give almost any bike a hard core look to it, not to mention a hardcore feel with a flex free handle bar. It is available in only 50mm and 70mm lengths, both with a 10 degree rise. Currently it is hard to find in shops as it is very popular and is selling fast. The price is also $115.00, and that is another improvement over last year's Raceface stem. This stem is a simple functional component that looks good and provides improved handle bar stiffness.
If forced to use only one stem for all round riding, the best value seems to be with the Thompson. It's clamping mechanism is by far the best of the three stems and its bar holding capabilities are great. It you want stiff and only need a shorter stem length, go with the Diabolous from Raceface. The Raceface SYStem is not recommended.
