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Direct Mount Stems, what's up?

TrekBro

Monkey
Jun 9, 2004
365
0
Greensboro NC
it's there any plans to make a Direct mount for Marzocchi's 888?, I personally don't like RS Boxxer's, but I would love to get an after Market direct mount Stem from you guys.
 
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dw

Wiffle Ball ninja
Sep 10, 2001
2,943
0
MV
it's is there any plans to make a Direct mount for Marzocchi's 888?, I personally don't like RS Boxxer's, but I would love to get an after Market direct mount Stem from you guys.
That's a great question.

Right now we have no plans of making a 888 stem. Actually, as of the end of the 2009 season, we've decided to discontinue the direct mount stem from our lineup.

Why would we do that you ask? (I figured I'd answer preemptively and save Jonas the time..)

Well, back in late 2003 or early 2004, my friend Jeremiah asked if I was interested in building a stem to support a new bolt on standard that he was working on. I was pretty down with the idea, so to support the cause we built some prototypes. The first prototypes worked out great, and I did a preproduction redesign to make the parts cheaper and lighter.

The stems were made from an expensive but very strong aluminum called 7075 T6, and through a lot of strain gaged testing (data aquisition where we actually measure the stress in the metal of the actual stem during use) and FEA we made what we felt was the lightest stem that would be safe for riders. For a few years, the e*thirteen ALI stem was the only 2-piece stem on the market, it was a pretty unique part. Partly because of the 2-piece design, the stem was also one of the strongest and lightest available, and today remains the highest strength and stiffness to weight ratio stem we've ever tested.

Then, a few companies here and there started making their own 2-piece knockoffs, and many of them are made from much weaker 6061 and REALLY LIGHT. Now we're no dummies, a couple years ago, downhillers were sacrificing durability for weight all over the place, but I just can't get behind doing that with a stem. If your stem breaks, you are in some serious trouble. Better be wearing a full face helmet, that's for sure.. If I see a broken stem EVER, I start asking questions, and I've seen WAY TOO MANY broken direct mount stems from random brands in 2008 and 2009. It's downright scary and some of these companies are (in my opinion) being pretty irresponsible playing with people's lives just to claim a light weight part and make a good profit.


So, In the beginning of 2008, we hired on a bright young engineer named Kris, and together him and I redesigned the stem to drop a little weight and lower bar height. With a little lower bar height, that stem was about as light as I could even imagine being safe. The new stem was still made from 7075T6, and when we looked more closely at the super light 6061 stems on the market, we realized that we just couldn't compete from a pricing standpoint and keep the same weight that we wanted, all without putting the rider in what we viewed as a dangerous situation.

The bottom line is that 6061 T6 is 1/2 the strength of 7075 T6 and also around 1/2 the price. If we wanted to stick to our mantra of providing the best product possible, typically with class leading strength to weight ratios, we were going to need to do so at a higher price than a competing unsafe 6061 stem, or at a higher weight than a competing unsafe 7075 stem. Maybe when the downhill riding public starts to chastise companies making overly lightweight and unsafe parts we'll take another shot at it, but until that time, I think we'll just sit this one out. There are plenty of other parts out there to work on!!

I'll see if I can find some pictures of the old prototypes and the 2008 design that never made it to market.
 
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no skid marks

Monkey
Jan 15, 2006
2,511
29
ACT Australia
DW do you by chance have any pics of any of the failed stems you've seen? I'm sure they'd have interested you to see where and why they failed. Would just like to see the common weak areas myself.
Surely your direct mount stems would still sell, shame to not stick with a product due to what others are doing.
Fight the Power.
 
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- seb

Turbo Monkey
Apr 10, 2002
2,924
1
UK
Partly because of the 2-piece design, the stem was also one of the strongest and lightest available, and today remains the highest strength and stiffness to weight ratio stem we've ever tested.
Of course that means less than nothing, as for all we know you've never tested any stems other than your own :)


Maybe when the downhill riding public starts to chastise companies making overly lightweight and unsafe parts we'll take another shot at it, but until that time, I think we'll just sit this one out.
So you're going to leave us with all of these light weak stems, with no strong heavy dependable e13 offering? You're basically killing us! :p
 

- seb

Turbo Monkey
Apr 10, 2002
2,924
1
UK
(Oh and FWIW I'm still running a standard Hope stem, I'm not getting uppity because you've dissed my £100 swiss-cheese DM stem! :))
 

dw

Wiffle Ball ninja
Sep 10, 2001
2,943
0
MV
DW do you by chance have any pics of any of the failed stems you've seen? I'm sure they'd have interested you to see where and why they failed. Would just like to see the common weak areas myself.
Surely your direct mount stems would still sell, shame to not stick with a product due to what others are doing.
Fight the Power.
I do, actually I've gotten most of them from Philip (e*thirteen tech support wildman). Riders seem to love to e-mail us pictures of other people's broken stuff and chat about it, and I appreciate it because the more information we see, the better the products we can build.

I've always thought it would be in bad taste to put pictures of other people's broken products up on the internet, I don't even really like to see that when riders do it. (unless the company is being socially irresponsible I guess, and public outcry is the only way to get the issue recognized and fixed..) Even then, it's "uncomfortable".

There have definitely been some pictures of broken stems online though, I've been forwarded links to them here and there. I'm sure that some sleuthing could turn up info..
 

dw

Wiffle Ball ninja
Sep 10, 2001
2,943
0
MV
Of course that means less than nothing, as for all we know you've never tested any stems other than your own :)
LOL, It would be a pretty asinine statement if we had only tested our own products! (but we did test ours first, as it was the first one we had way back in the day)

So you're going to leave us with all of these light weak stems, with no strong heavy dependable e13 offering? You're basically killing us! :p
I think of it as the exact opposite. You see, the whole "strength, weight, and cost, pick two" adage really works here. We CNC allof our stems (and all other e*thirteen CNC and plastics) right here in the USA. It's more expensive than Taiwan. Actually, seeing as we aren't selling the things anymore, I'll tell you straight up, it cost us around $30 per stem to manufacture, and we didn't sell it for much more to distributors.

We could build the 2008 redesigned stem out of 7075, it would be super light, with much greater strength and reliability than most offerings, and it would be more expensive than the 6061 stems on the market.

I'm not into compromising strength and weight ever. That's why it's such a challenge designing parts that meet those criteria and still have a competitive price. I think that we've done a killer job of that over the years on chain retention systems.

On stems, if you pick weight and cost, you give up strength. That's the avenue that some have gone, but then they go and market the product like it's some really strong part. Riders buy into it, believing the advertising. I think that there should be laws against that.

So really Seb, I think that we're SAVING you by not getting involved! Of course we reserve the right to change our minds and jump back into the fray at any moment.
 

dw

Wiffle Ball ninja
Sep 10, 2001
2,943
0
MV
(Oh and FWIW I'm still running a standard Hope stem, I'm not getting uppity because you've dissed my £100 swiss-cheese DM stem! :))
Hey, it's good conversation as far as I'm concerned, and I think that you brought up a couple great points!
 

PhilipW

Monkey
Mar 13, 2007
311
0
Leominster, MA
You see, the whole "strength, weight, and cost, pick two" adage really works here.

I'm not into compromising strength and weight ever. That's why it's such a challenge designing parts that meet those criteria and still have a competitive price.
A pretty well known up and coming trashed his lightweight stem at one of the WC's in Canada in a crash. Two lessons - don't use Ti hardware in stems and lightweight parts break much quicker in a crash.

It is my personal preference to sacrifice a few grams for a much stronger part. In the case of this rider, how many extra DM stems do you think you could find at a WC race, and be able to scrounge one up? How many people would carry an extra stem at a local race? We ride DH bikes, not road bikes. There are places to save weight, but in the end you have to be reasonable about it.

Some things you expect to go through (tires, brakepads, rims, etc), but a broken stem shouldn't end your weekend (or season or life) due to being too light/not strong enough.

-philip :pirate:
 
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DerekJ

Monkey
Mar 6, 2006
151
0
Taichung, Taiwan
DW here adding some comments to the pictures that D ROD put up.

So here are some pictures of the very first e*thirteen direct mount stem prototype. You will notice that it's a little different than the production stems in design. It was shown in Decline years back, one of the early years issues. We made 5 prototypes, I ran this stem on my personal bike during the 2004 season, and Sam Hill and Nathan Rennie ran them also. One was kept for CMM measurement and the other was used for mechanical testing.


You can see in this photo that the stem has a pocket for the bolts instead of the one-sided structure that we went to later. The pocket ended up being costly to manufacture and because the 31.8 bars are so stiff, overall system stiffness was not improved with the pocket design (compared to the one-sided design.)

The choice to go with the two piece design over a 1 piece design or a full faceplate was pretty easy. When was the last time you slipped your bars in your stem? Think about it..

Yeah, me neither. It does not happen, and for good reason. When you run the numbers, it's basically impossible. Even with a 25.4 bar you still can't slip the bar to stem interface. The bar to stem interface if incredibly strong, and IMO, the only reason to go one piece on the body or faceplate is for added cosmetics. Structurally it does little to benefit. As you will see on the 2008 prototype later next week, we did explore some cosmetic benefits.

I chose to put the support structure of the stem on the outside of the bolts rather than the inside becuase when we tested this prototype, there were all kinds of head tube spacers that interfered with the stem itself. Our friends at SIC were the only other company who built a stem to meet the standard originally, and they ran into the same problem. We ran a bunch of FEA and found that running the bar supports outside the bolts as opposed to inside gave an almost identical stiffness and strength to running them inside, but we never would have to worry about spacer issues. I estimated that we added 4g. to the design by going outboard vs. inboard with the supports. It's crazy sometimnes what drives design decisions! You would be amazed how much derailleur location affects suspension layout sometimes..


If you lok REALLLLLLY close, you can see the machining marks in the crown. This part was made on either a 3 or 5 axis CNC milling machine, and back in 2003, it was pretty damn cool to have this on your bike. I'd be lying if I said I didn't feel a little bit special to have a prototype air Boxxer with this CNC'd crown, a prototype direct mount stem, all on a prototype bike from a basically unknown catalog company that would in a year be the archetype for a whole new generation of downhill bikes and geometry.

There is some mud in there, and I can almost guarantee that's the stickiest of the icky icky from West Virginia 2004. Man what a mud fest that was..


Next week sometime, I'll work on getting up some pictures of the 2008 prototypes that never made production.
 
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Jonas

Monkey
Feb 11, 2004
141
0
East Coast Represent!
Hi manhattan,
For the reasons mentioned by dw earlier in the post we have ceased making the ALI Direct Mount Stem for the time being. There may be some distributors or dealers that have some leftover inventory but it's probably unlikely. The ALI Stem proved to be quite a popular product and they never sat on the shelf for very long. This doesn't mean there are none out there to be sold/purchased but e*thirteen has not sent any distributor any ALI stems in a couple months. We don't even have any here at our own office in Massachusetts.
I'm fairly certain that our major US distributors are sold out.
We appreciate the interest though and wish you the best in your efforts to hunt one down.
If you ever have any questions regarding any e*thirteen product please feel free to get in touch with us directly.

Regards,
Jonas
 

manhattanprjkt83

Rusty Trombone
Jul 10, 2003
9,644
1,214
Nilbog
Jonas,

Thanks man, appreciate it...I didnt read the entire thread just saw direct mount and posted...Keep up the the good work guys, love your products. Looks like my buds at cromag will get the vote for next seasons stem...

cheers.
 

FOXROX

Turbo Monkey
Jun 23, 2007
2,120
0
hambur,nj
derekj- thanks for doing that write up! it was really interesting to hear about that, and from an engineers stand point.
 

Dean W

Chimp
Nov 26, 2008
31
0
...............Next week sometime, I'll work on getting up some pictures of the 2008 prototypes that never made production.
So what happened to the update. I'm interested in seeing how you guys redesigned your DM stem.