# Extralite Ultrastem UL3 86,31 g !!!!!



## Dream Bikes (Oct 1, 2005)

100 mm on my "pusher" scale!!!! Incredible weight!!!!
Tomorrow I'll add other pictures which shows the difference between UL2/UL3....


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## protocol_droid (Jul 7, 2004)

That's friggin light. I wonder how this one compares strengthwise to the syntace. It does say it's fatigue tested to uni 10518 standards, not sure what that means though.


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## Onie (Sep 15, 2005)

Yeah, how does it compare with Syntace, that is, strengthwise..? Before I make the big shift!


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## Dream Bikes (Oct 1, 2005)

Stiffness increase with diameter and Ultrastem is very large....more than a lot of others stems!!


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## Dream Bikes (Oct 1, 2005)

Other pictures :


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## Dream Bikes (Oct 1, 2005)

UL3 & UL2


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## protocol_droid (Jul 7, 2004)

Dream Bikes said:


> Stiffness increase with diameter and Ultrastem is very large....more than a lot of others stems!!


Yes, but increasing the diameter says nothing of the thickness used when going to larger diameter. The difference between the ul2 and ul3 seems to be just shaving away some dimples around the ti bolt areas. If that's the case, the diamter and thickness are most likely the same between the the ul2 and ul3. Now the difference between ul3 and the f99?


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## DIRT BOY (Aug 22, 2002)

protocol_droid said:


> Yes, but increasing the diameter says nothing of the thickness used when going to larger diameter. The difference between the ul2 and ul3 seems to be just shaving away some dimples around the ti bolt areas. If that's the case, the diamter and thickness are most likely the same between the the ul2 and ul3. Now the difference between ul3 and the f99?


I have used the UL2 and F99 on the MTB and the RoadStem 2UL2 (a very close design to the MTB UL3) and a F99 99 on the road bike.

Both stem feel equally stiff on or off road. IF there is any differnce I can't fell it at all. The EL is a god bit lighter, but costs twice as much. ersoanlly on looks alone I prefer the EL much, much better. I think the F99 nnneds a face light. I am running a Ritchey 4-Axis 31.8 on the raod bike instead of the F119 due to looks alone.

The scary part is the UL3 is almost as light as the RoadStem UL2 (81g/100mm) now.


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## Dream Bikes (Oct 1, 2005)

protocol_droid said:


> Yes, but increasing the diameter says nothing of the thickness used when going to larger diameter. The difference between the ul2 and ul3 seems to be just shaving away some dimples around the ti bolt areas. If that's the case, the diamter and thickness are most likely the same between the the ul2 and ul3. Now the difference between ul3 and the f99?


I didn't say that UL3 is stiffler than UL2, it's simply lighter!!!!

Bending stiffness is defined by moment of inertia (and Young's modulus of the material). Moment of inertia of a circular hollow section, like a stem) is defined as follows:



torsional rigidity is defined by polar moment of inertia. It's equal do double of moment of inertia for this type of section. So same considerations are valid.
as formulas shows rigidity modulus increases with fourth power of the diameter. We have a big ingrease of rigidity with an increase of diameter.
we can do an example: consider 2 stems of equal weight, one of 30mm diameter(forged stem) and another of 35mm diameter (UltraStem).



35 mm stem have a stiffness greater than 40%!!
stresses decreases with third power of diameter, 30mm stem suffer a stress greater than 20%, less safe and life-longer


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## sergio_pt (Jan 29, 2007)

Nice explanation! :thumbsup: 
"torsional rigidity is defined by polar moment of inertia" Can you explain this better? Whats the formula to calculate that?


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## top_ring (Feb 9, 2004)

I'm no metalurgist, but I too have owned the UL2 and the F99. I have deliberately put them through stressful situations (not wanting to have them fail) before I used them on a daily basis. In my experience... the Extralite flexed less then the F99.

Regardless of this the UL3 may end up flexing _more_. Taking material off the area around the steer tube clamp _might_ promote that. This may mean that it's just not as "stiff" as it's 1st generation counterpart - the UL2. Very cool though and beautiful craftsmanship from Extralite as usual.


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## Dream Bikes (Oct 1, 2005)

sergio_pt said:


> Nice explanation! :thumbsup:
> "torsional rigidity is defined by polar moment of inertia" Can you explain this better? Whats the formula to calculate that?


J = p * D4 / 64 - p * d4 / 64

J = moment of inertia of a circular section
p = 3.14...
D = outside diameter D4 = D x D x D x D
d = inside diameter d4 = d x d x d x d


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## Onie (Sep 15, 2005)

*Trip down the Memory Lane*



Nice formulas there! :thumbsup:

Brings back the "baddest" :madmax: of memories during my university days! LoL! Now, I just have to get my grubby hands on my ol' text books in Physics, et al. Start browsing 'em up for the nth time! 

So, UL3, it is! :cornut:

Thanks!


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## ginsu2k (Jul 28, 2006)

While the split for the clamping system might be for a light design, it also puts a hole right were the region of greatest stress is on the stem, a perfect place for cracks to start. Luckily you can watch it quite easily for any cracks to appear, but it is not an ideal location to split like that.


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## Dream Bikes (Oct 1, 2005)

ginsu2k said:


> While the split for the clamping system might be for a light design, it also puts a hole right were the region of greatest stress is on the stem, a perfect place for cracks to start. Luckily you can watch it quite easily for any cracks to appear, but it is not an ideal location to split like that.


After generations of stems, after several years of machining, FEM analysis, safety tests and continuos development, do you think that UL3 could be dangerous????:madman:

If you're mistrustful check it with a Finite Element Analysis...I saw that you like to play with Catia...but please this time apply loads in the right direction!!!!


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## DIRT BOY (Aug 22, 2002)

quote=Dream Bikes]After generations of stems, after several years of machining, FEM analysis, safety tests and continuos development, do you think that UL3 could be dangerous????:madman: 
[/quote]
*Sure!! *
The UltraStem UL or UL2 (can't remember which one.) first generation had issues with the face clamp cracking. This happened to ME and 3-4 customers. All face clamps were replaced under warranty with the "new designed" face clamps per Extralite.

Sergio said there were a few issues and they were redesigned. I wish I could go back 2-3 yrs on the e-mail.

So sure it could happen. But I hope they leaned from that mistake. I assume they did as I never had another issues with my clamp or any other stem I sold after that. That includes years of using the road version as well. When the new RoadStem OC is available, that heavy Ritchey is heading for eBay.


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## BlownCivic (Sep 12, 2006)

ginsu2k said:


> While the split for the clamping system might be for a light design, it also puts a hole right were the region of greatest stress is on the stem, a perfect place for cracks to start.


The w*hole* reason for that round hole at the end of the split is to prevent cracks from starting there.


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## rapsac (Sep 26, 2004)

Yeah, the round hole is to prevent stress risers. But then again, he probably meant the construction, not just the round hole itself.
BTW, I have just bought one of the last UL2's I could find to replace my heavy Thomson Elite stem ;-)


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## ginsu2k (Jul 28, 2006)

BlownCivic said:


> The w*hole* reason for that round hole at the end of the split is to prevent cracks from starting there.


Yeah, of course, or a crack would probably start the first time you ride it. I just don't think it's a great design, and I wouldn't be surprised to see some cracks start there.


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## Dream Bikes (Oct 1, 2005)

ginsu2k said:


> Yeah, of course, or a crack would probably start the first time you ride it. I just don't think it's a great design, and I wouldn't be surprised to see some cracks start there.


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## Slobberdoggy (Sep 26, 2005)

*Initial Impressions*

I was able to order 110mm direct. It came relatively quick compared sbikes shipping and getting EL stuff through the part pushers  around here. 2 weeks iirc. Obviously that can depend also if the part dealers in the US have them in stock - that would be quickest.

I've only done 100 miles. Previously used the f99 on another bike. The stem is machined really well. It's really hard for me to comment on stiffness when I run such a noodlely fork.

My only problem is despite the handlebar clamp holding really well the ultralow bolt torque on the steerer tube is having trouble holding the stem and fork straight. Usually you will notice an alignment problem after a rough technical section. This was with no grease on the steerer tube. The stem seems to come with some lube on the bolts so I haven't touched them. So finally I decided to put a thin layer of TACX grease on the steerer. It has very fine particles in it to help grip stuff. This helped - a little - but when I stand up and sprint or try to get out of a hill climb bind - it/they CREAK like crazy.

Hmm. . . might try regular grease next. I'm not too concerned. This is just the initial report. I'll try regular grease. Later, check out a different bolt lube. I wonder if they came with that lithium grease on the bolts - it looked kind of different?


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## Onie (Sep 15, 2005)

I'll just stay tuned, Slobber. Thanks for the write-up! :thumbsup:


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## rapsac (Sep 26, 2004)

*Extralite clampstyle is very sensitive ...*

... to size tolerances of the streerer tube of your fork.
I have an UL2 stem, this also had to be put on the steerer tube with "carbon paste" (friction enhancement paste). Plain grease or white assembly grease will not work... you will just rotate your stem (this reduces friction!).
What you should be carefull of (because of creaking) is that the friction paste is not present between stem and spacers, spacer and spacer or steerer tube and spacer, headset and spacer... so only between steerer tube and inner area of stem clamp.
Note that I have also read reports of people having to use locktite...

PS: I have a Reba Team fork.


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## $mokeyJoe (Sep 18, 2005)

I'm also using the UL3,but i've removed the original paste and i always use coppergrease with the recommended bolt torque.I didn't have to re-alligne the bar or so after 3 months of using(off-road of course!)
Actually i put on every Ti bolt coppergrease.

First i had the UL2.I haven't noticed any difference on the stem.It's just lighter...and more beautifull.I run the stem upside-down.


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## Slobberdoggy (Sep 26, 2005)

rapsac said:


> ... to size tolerances of the streerer tube of your fork.
> I have an UL2 stem, this also had to be put on the steerer tube with "carbon paste" (friction enhancement paste). Plain grease or white assembly grease will not work... you will just rotate your stem (this reduces friction!).
> What you should be carefull of (because of creaking) is that the friction paste is not present between stem and spacers, spacer and spacer or steerer tube and spacer, headset and spacer... so only between steerer tube and inner area of stem clamp.
> Note that I have also read reports of people having to use locktite...
> ...


None of this crap is working. I installed a 120mm F99 stem and it is stiffer. It's not creaking but I did wipe off all the tacx. I tried everything I think. I'm not sure what I will run on my race bike but probably the syntace that with ti bolts will be a little lighter. EL stem may find it's way onto my beer brawl bike which will be fitting since it is a Carver RC1.


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## miketech1 (Jun 20, 2006)

Sure is puurrttyy though. Much nicer than the syntace.


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## RWGreen (Dec 5, 2004)

I had a similar experience to others with the stem twisting on the steer tube during more technical manuvers. It was tightened to recommended torques. 

There is a fairly large log pile on one of my local trails that you need to make a little bit of a right turn on top of, and every time the stem would just twist on the steerer. I find this type of product a little scary.


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## Ole (Feb 22, 2004)

Use some 1000 grit emery paper to roughen up the inside surface of the steer tube clamp in the stem, and do the same thing on the outside of the steer tube. I've been doing that since the original UltraStem, and have not had any problems with slippage since.


Ole.


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## Slobberdoggy (Sep 26, 2005)

*Surprise Surprise*

So now that I have a proper fork I rode once with the syntace and then switched back to the UL3. I didn't put any tacx paste on it. FWIW the steerer tube length of the syntace is shorter (good thing I measured using my previous spacer setup  ).

No creaks at all. With a stiffer fork it feels much better but is a little flexier (I think) than the syntace. The area right in front of the steerer is suspect to me. Rest assured I'll be inspecting this stem all the time. Also no slipping so far either! The Fox steerer has a very coarse surface (forged?) cf. to the spinner. I did tight'n just a tiny amount over the 3.5nm's limit.

So that said - I really like it again and I would recommend it again. Of course the problems I had before were very real. The tacx seemed to activate the creaking but did hold it a little better.

I think the Zeus stem could be a good stem too


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## dejacky (Jun 27, 2006)

so does this ul3 work fine now or still giving people problems? how about flex?


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## Dream Bikes (Oct 1, 2005)

I'm very happy with my UL3, it looks fine and works very well (I'm 73 kg)


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## Slobberdoggy (Sep 26, 2005)

Mine hasn't broken. I'm 85 kilos. My only occasional issue is with the low torque settings. I usually go slightly higher and I still occasionally have the bar or steerer clamps slip on technical stuff.


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## dejacky (Jun 27, 2006)

do you experienced UL3 owners think this stem will work fine on an all mountain bike with 5 inches of suspension travel? There is no noticeable flex with this stem correct? I weight 215lbs.


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## TheRedMantra (Jan 12, 2004)

dejacky said:


> do you experienced UL3 owners think this stem will work fine on an all mountain bike with 5 inches of suspension travel? There is no noticeable flex with this stem correct? I weight 215lbs.


If you are honestly considering using the stem for this application why not just email extralite direct? They will give you the best answer; rather than speculation from actual users who no doubt have not tried the setup you propose. I would imagine that they would not recommend you try to use an UL3 for an all-mtn bike. I may be wrong, but I just say that because I don't know how comfortable I would be using this setup. I would love the stem on my XC bikes but its so $$$ I'll just stick with my ritchey wcs and mission control stems. Also think about how most lightweight parts have weight limits. Most weight limits are far under what you weigh. 215Lbs+ gear is a lot. I'm not calling you fat, just saying that you should consider a beefier stem for your safety.


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