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  1. #1
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    Extralite Ultrastem UL3 86,31 g !!!!!

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






  2. #2
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    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.

  3. #3
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    Yeah, how does it compare with Syntace, that is, strengthwise..? Before I make the big shift!
    Quote Originally Posted by jcatienza
    There was no need to scare potential buyers and burn bridges "buddy"
    Tell me now, what's Product testing all bout then?

  4. #4
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    Stiffness increase with diameter and Ultrastem is very large....more than a lot of others stems!!

  5. #5
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    Other pictures :










  6. #6
    The "pusher"..
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    UL3 & UL2














  7. #7
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    Quote Originally Posted by Dream Bikes
    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?

  8. #8
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    Quote Originally Posted by protocol_droid
    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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  9. #9
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    Quote Originally Posted by protocol_droid
    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

  10. #10
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    Nice explanation!
    "torsional rigidity is defined by polar moment of inertia" Can you explain this better? Whats the formula to calculate that?

  11. #11
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    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.

  12. #12
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    Quote Originally Posted by sergio_pt
    Nice explanation!
    "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

  13. #13
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    Trip down the Memory Lane




    Nice formulas there!

    Brings back the "baddest" 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!

    Thanks!
    Quote Originally Posted by jcatienza
    There was no need to scare potential buyers and burn bridges "buddy"
    Tell me now, what's Product testing all bout then?

  14. #14
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    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.

  15. #15
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    Quote Originally Posted by ginsu2k
    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????

    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!!!!

  16. #16
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    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????
    [/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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  17. #17
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    Quote Originally Posted by ginsu2k
    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 whole reason for that round hole at the end of the split is to prevent cracks from starting there.

  18. #18
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    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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  19. #19
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    Quote Originally Posted by BlownCivic
    The whole 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.

  20. #20
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    Quote Originally Posted by ginsu2k
    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.

  21. #21
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    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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  22. #22
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    I'll just stay tuned, Slobber. Thanks for the write-up!
    Quote Originally Posted by jcatienza
    There was no need to scare potential buyers and burn bridges "buddy"
    Tell me now, what's Product testing all bout then?

  23. #23
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    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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  24. #24
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    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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    Last edited by $mokeyJoe; 08-19-2007 at 04:39 AM. Reason: picture added

  25. #25
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    Quote Originally Posted by rapsac
    ... 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.
    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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