emilydickinson
04-05-2005, 02:23 AM
I first became curious about the Odyssey Elementary stem when I noticed that all the pictures of George French's bike on the G-Sport website had the stem blacked out. What stem could be so unique that it has do be blacked out for intellectual property and security reasons? I had seen pictures of the earlier G-Sport Nimrod stem, and it seemed like a great stem, but I had never seen one in person, so I can't comment on it. However, the design seemed good in practice. Fast forward to the current time. Since I first read about the Elementary stem, designed by George French and produced by Odyssey, I was very excited. Once I saw pictures of it, and read about the one bolt compression wedge system, I knew it was something special. New BMX parts seem to appear on a weekly basis, but for the most part they are clones, or slight refinments of existing designs. There is very little innovation in the engineering department in the world of BMX. Part design is driven by trends, not improvemement. The Elementary stem is a true innovation: it does the job of a traditional stem in a simpler, more efficient, more elegant way, while managing to weigh much less. That is an innovation.
'Simplicity is the hallmark of good engineering'. You hear this again and again in engineering school. The best designs are the simplest: they have the fewest parts, so they have the fewest reasons to fail. The Elementary stem uses a one bolt system which drives two compression wedges to hold the bars and the steering tube snug at the same time. Instead of having 6-8 bolts to tighten, there is one. When this bolt is tightened, the compression wedges move outwards and provide the clamping force in two places. That's a simple elegant design, and in theory provides more clamping power than is possible with a standard stem, where the friction on the bolt threads provides all the clamping force. Using a frame and wedges eliminates all the excess metal in traditional stem designs, creating a huge weight savings. I'm not a weight geek, but if I can run a stem that weighs 230 grams and has superior clamping power, I'm into that. The weight savings is right at the bars, making the front end lighter and providing more pop, so saving weight at that place on a BMX is also good. At this point, I'll also admit my own prejudices. I'm a mechanical engineer, just like G.F., so I feel better knowing a rider who knows his basics designed this, and not some hipster who's more concerned with looks than performance.
Here's the stem, and it's fancy packaging.
Here's the stem dissasembled so you can get a good look at the guts. On the right is the U-Frame, the main body of the stem. The top two pieces are the spacers which hold the steerer tube and bars taught against the compression wedges. On the bottom are the two compression wedges, threaded together with an 8mm bolt, washer and mating nut, which sit flush in the wedges.
Installing the Elementary Stem
Installing the Elementary stem may seem difficult at first, but that's only because it's done completely different than installing a traditional stem. In many ways it is comparable to the scene in 'Jane Eyre' where Mr. Rochester dresses up as a gypsy. Seemingly bizarre, but in the end it only ends up being something good. Let's gather our tools for the installation. You'll need ann engineer's scale (a ruler, or a tape measure will also suffice), a 9/16's socket for the compression bolt in your headset, an 8mm hex key (thoughtfully supplied by Ody with the stem) and grease, That's it. Personally, I love Phil Wood grease. Yes, it's expensive, but you have to admit there is something clean about it, and it does last forever.
The first thing we need to do is measure out steere tube. Take your scale and place it at the top of the headset where the steerer tube exits. Measure from there to the top of the steerer tube. Ody reccomends your steerer tube to be at least 36mm. Mine was 40mm, and I would bet most people who aren't weight retards who cut there steerer tubes to lose 5 grams will be fine. Cut your steerer tube too short? Sorry, you're shit out of luck. I've warned you to not cut things off your bike, you might need them later.
Now that we've checked our steere tube, and see that it is of sufficient length, we can get to work. Take some grease and grease the isnside of the U-Frame where it will contact the steerer tube.
Now take your bars, and slide them into the U-Frame of the stem. This may require a bit of force, which is fine. Just shove them into the front of the U-Frame. Put your back into it.
With the bars secureley in the frame, place the circular opening in the U-Frame over the steerer tube, and push it down until it is flush with the top of the headset. I needed to remove a spacer to make this happen.
Once the frame is sitting flush on the steerer tube, insert the the wedge with the flat plane into the front of the tube facing the handlebars.
Now, insert the second wedge with the more pronounced curved depression into the side of the U-Frame facing the steerer tube. It should rest snugly against the steerer tube.
With both wedges tucked into place, it's time for the compression bolt, the linch pin of the whole stem. Grease is more than an amazing movie with Stockard Channing and John Travolta-grease the vertical planes (up and down) of the compression wedges. Then slide the bolt and nut side of the wedges into the U-Frame between the two spacers.
Place the wedges so that sit evenly in the frame, and are flush inside it. I they stick out, it will be a bitch to fix it later.
With the bars, frame, spacers and wedges in place, place your bars in the correct position. I reccomend that your bars are parellel with the the axel nuts on your front fork. See this pic.
With the bars in place, stand over your bike and align the stem and the bars so they are perfectly straight.
Now, take your 9/16 socket, and tighten down the compression bolt until it is very snug (don't worry that spacer will give you some wiggle room).
With the compression , bolt snug, take the 8mm allen key and begin tightening the bolt in the compression wedges. Be careful here. All the rumors about people crushing there bars with this stem are tru - it has that much clamping power. Tighten about three turns withe allen key, then go in quarter turn increments until it is snug. Ody suggests a tork taing of 18-25 N-m. Most people don't have torqe wrenches, so go slow, and as soon as you can't move the bars, stop tightening.
All pieces of the compression wedges should be inside the U-Frame when you are done tighetning the bolt.
The bolt should be flush with the U-Frame.
Here's a shot with the stem fully tightened,
Looks cool, eh?
With your stem fully installed, go for a ride. I immediately noticed the weight difference in my front end. It actually feels lighter, and my bike has more pop. I've had this stem for about three months, and there has been no bar slippage at all. It rocks. People are cutting there axels to save weight, but this stem will save a lot mor weight while working better han heavier stems on the market. The Elemenatery stem is the most innovative product for BMX that we've seen in a while. Lighter weight, better clamping power, and a simpler mechanical design all make this the best part to come along in years. Get one - it rocks. And as usual, I know what is best for everyone. - Emily Dickinson
'Simplicity is the hallmark of good engineering'. You hear this again and again in engineering school. The best designs are the simplest: they have the fewest parts, so they have the fewest reasons to fail. The Elementary stem uses a one bolt system which drives two compression wedges to hold the bars and the steering tube snug at the same time. Instead of having 6-8 bolts to tighten, there is one. When this bolt is tightened, the compression wedges move outwards and provide the clamping force in two places. That's a simple elegant design, and in theory provides more clamping power than is possible with a standard stem, where the friction on the bolt threads provides all the clamping force. Using a frame and wedges eliminates all the excess metal in traditional stem designs, creating a huge weight savings. I'm not a weight geek, but if I can run a stem that weighs 230 grams and has superior clamping power, I'm into that. The weight savings is right at the bars, making the front end lighter and providing more pop, so saving weight at that place on a BMX is also good. At this point, I'll also admit my own prejudices. I'm a mechanical engineer, just like G.F., so I feel better knowing a rider who knows his basics designed this, and not some hipster who's more concerned with looks than performance.
Here's the stem, and it's fancy packaging.
Here's the stem dissasembled so you can get a good look at the guts. On the right is the U-Frame, the main body of the stem. The top two pieces are the spacers which hold the steerer tube and bars taught against the compression wedges. On the bottom are the two compression wedges, threaded together with an 8mm bolt, washer and mating nut, which sit flush in the wedges.
Installing the Elementary Stem
Installing the Elementary stem may seem difficult at first, but that's only because it's done completely different than installing a traditional stem. In many ways it is comparable to the scene in 'Jane Eyre' where Mr. Rochester dresses up as a gypsy. Seemingly bizarre, but in the end it only ends up being something good. Let's gather our tools for the installation. You'll need ann engineer's scale (a ruler, or a tape measure will also suffice), a 9/16's socket for the compression bolt in your headset, an 8mm hex key (thoughtfully supplied by Ody with the stem) and grease, That's it. Personally, I love Phil Wood grease. Yes, it's expensive, but you have to admit there is something clean about it, and it does last forever.
The first thing we need to do is measure out steere tube. Take your scale and place it at the top of the headset where the steerer tube exits. Measure from there to the top of the steerer tube. Ody reccomends your steerer tube to be at least 36mm. Mine was 40mm, and I would bet most people who aren't weight retards who cut there steerer tubes to lose 5 grams will be fine. Cut your steerer tube too short? Sorry, you're shit out of luck. I've warned you to not cut things off your bike, you might need them later.
Now that we've checked our steere tube, and see that it is of sufficient length, we can get to work. Take some grease and grease the isnside of the U-Frame where it will contact the steerer tube.
Now take your bars, and slide them into the U-Frame of the stem. This may require a bit of force, which is fine. Just shove them into the front of the U-Frame. Put your back into it.
With the bars secureley in the frame, place the circular opening in the U-Frame over the steerer tube, and push it down until it is flush with the top of the headset. I needed to remove a spacer to make this happen.
Once the frame is sitting flush on the steerer tube, insert the the wedge with the flat plane into the front of the tube facing the handlebars.
Now, insert the second wedge with the more pronounced curved depression into the side of the U-Frame facing the steerer tube. It should rest snugly against the steerer tube.
With both wedges tucked into place, it's time for the compression bolt, the linch pin of the whole stem. Grease is more than an amazing movie with Stockard Channing and John Travolta-grease the vertical planes (up and down) of the compression wedges. Then slide the bolt and nut side of the wedges into the U-Frame between the two spacers.
Place the wedges so that sit evenly in the frame, and are flush inside it. I they stick out, it will be a bitch to fix it later.
With the bars, frame, spacers and wedges in place, place your bars in the correct position. I reccomend that your bars are parellel with the the axel nuts on your front fork. See this pic.
With the bars in place, stand over your bike and align the stem and the bars so they are perfectly straight.
Now, take your 9/16 socket, and tighten down the compression bolt until it is very snug (don't worry that spacer will give you some wiggle room).
With the compression , bolt snug, take the 8mm allen key and begin tightening the bolt in the compression wedges. Be careful here. All the rumors about people crushing there bars with this stem are tru - it has that much clamping power. Tighten about three turns withe allen key, then go in quarter turn increments until it is snug. Ody suggests a tork taing of 18-25 N-m. Most people don't have torqe wrenches, so go slow, and as soon as you can't move the bars, stop tightening.
All pieces of the compression wedges should be inside the U-Frame when you are done tighetning the bolt.
The bolt should be flush with the U-Frame.
Here's a shot with the stem fully tightened,
Looks cool, eh?
With your stem fully installed, go for a ride. I immediately noticed the weight difference in my front end. It actually feels lighter, and my bike has more pop. I've had this stem for about three months, and there has been no bar slippage at all. It rocks. People are cutting there axels to save weight, but this stem will save a lot mor weight while working better han heavier stems on the market. The Elemenatery stem is the most innovative product for BMX that we've seen in a while. Lighter weight, better clamping power, and a simpler mechanical design all make this the best part to come along in years. Get one - it rocks. And as usual, I know what is best for everyone. - Emily Dickinson