Advertise on Bikeforums.net



User Tag List

Page 1 of 2 12 LastLast
Results 1 to 25 of 32

Thread: Zertz?

  1. #1
    Senior Member dauphin's Avatar
    Join Date
    Jun 2006
    Location
    California
    Posts
    2,993
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Zertz?

    I have been thinking about a new seat post for my bike and was wondering about the benefits of carbon. I see Specialized talking about "Zertz" inserts and I have no clue what that means. If anyone has the answer or some general thoughts about a carbon seat post it would be much appreciated.

  2. #2
    Semper Fidelis
    Join Date
    Apr 2006
    My Bikes
    Tiemeyer Road Bike & Ridley Domicles
    Posts
    2,945
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    the zerts are inserts put into the carbon that is suppose to help dampen the shock.
    I have never really delved into the main theory behind it, but I personally believe it is just a sales gimmick.
    I really don't believe there is any benefit to them.

    Bontrager makes a nice carbon post with one adjusting bolt on the side, for the fore and aft or tilt, as well as different degreeded set-back
    "Advantages Must Be Pressed, Disadvantages Must Be Overcome"

  3. #3
    Senior Member NOS88's Avatar
    Join Date
    Mar 2006
    Location
    Montgomery County, Pennsylvania
    Posts
    6,417
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    My Roubaix Pro had the Specialized seatpost. I had to replace it. Despite using a torque wrench at the proper setting the post was damaged by an off-set seatpost clamp, making it unsafe to ride. I later came to learn that the carbon in the Specialized post is especially thin. I've got over 300 miles on a new alum Bontrager seatpost with a single allen wrench adjustment. I notice absolutely no difference between the ride of the old carbon and the new alum posts. Lowering you tire pressure by five lbs is likely to make more of a difference than the seatpost.

    Disclaimer: This is just my experience. The experience of others may vary, as I suspect you'll find quickly enough.
    A conclusion is the place where you got tired of thinking. - S. Wright

  4. #4
    Pinstriper SemperFi's Avatar
    Join Date
    Mar 2006
    Location
    Brooklyn, NY
    My Bikes
    05' Specialized Sequoia Elite, Raleigh M40 Mountain Bike
    Posts
    489
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    My Specialized Sequoia Elite has Zertz inserts in the front and rear forks.
    Can't tell you if they make a difference or not, but they look nice.
    HAMMER MAN is probably right...just a sales gimmick.
    Specialized Sequoia Elite
    Ride On!

  5. #5
    On the road again
    Join Date
    Aug 2005
    Location
    Columbus, Ohio
    My Bikes
    Specialized Roubaix, Cannondale R6000
    Posts
    127
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I've got a Specialized Roubaix Triple Comp and it has Zertz inserts and the ride is definitely smoother than my Cannondale but Cannondales are known for "presenting" all the road to be experienced plus I couldn't tell you how much is due to the Zertz and how much is just having a carbon frame and forks and post and bars. I too am always leary of many of the claims around these types of add-ons.

  6. #6
    Senior Member dauphin's Avatar
    Join Date
    Jun 2006
    Location
    California
    Posts
    2,993
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    So, even if Zertz is just a sales gimmick...what do you guys think about a carbon seat post?

  7. #7
    Senior Member
    Join Date
    Oct 2006
    Location
    NJ
    Posts
    383
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    is the zertz insert necessary for safety's sake? There is a specialized frame that is currently being sold at a nice price, but is missing the zertz insert on the seat stays. The sale is just the frame, nothing else (fork, seatpost, etc).
    Would I need to put a zertz insert in it before I ride?

    I don't see how a missing insert could lead to it collapsing. Thanks!

  8. #8
    Time for a change. stapfam's Avatar
    Join Date
    Jan 2004
    Location
    6 miles inland from the coast of Sussex, in the South East of England
    My Bikes
    Dale MT2000. Bianchi FS920 Kona Explosif. Giant TCR C. Boreas Ignis. Pinarello Fp Uno.
    Posts
    19,915
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by dauphin
    So, even if Zertz is just a sales gimmick...what do you guys think about a carbon seat post?
    Don't like Carbon Fibre. It has a habit of being damaged without giving any outward signs that it is damaged. When C.F. is damaged- it breaks without any form of warning whatsoever. It can be damaged in so many ways. Problem in production, Overtightening of the seat clamp, Sudden impact that damages it internally without any sign that you can see, and the worst one out of the lot-It can break for no apparant reason.

    It may be light and it may take some of the sting out of a harsh ride but not for me.
    How long was I in the army? Five foot seven.


    Spike Milligan

  9. #9
    Senior Member
    Join Date
    May 2005
    Location
    Fort Collins, CO
    Posts
    323
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by stapfam
    Don't like Carbon Fibre. It has a habit of being damaged without giving any outward signs that it is damaged. When C.F. is damaged- it breaks without any form of warning whatsoever. It can be damaged in so many ways. Problem in production, Overtightening of the seat clamp, Sudden impact that damages it internally without any sign that you can see, and the worst one out of the lot-It can break for no apparant reason.

    It may be light and it may take some of the sting out of a harsh ride but not for me.
    So when Boeing starts selling their 787 carbon fibre plane I guess you won't be flying on it

  10. #10
    Senior Member Coloradopenguin's Avatar
    Join Date
    Jul 2006
    Location
    Delta, Colorado
    My Bikes
    2007 Specialized Sirrus Comp, 1988 Diamond Back Ascent
    Posts
    304
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    My new Sirrus Comp has the zertz on the seat stays and front fork . . . Specialize offers documentation to show they work, but I think it really is just a marketing gimmick with cool looks.

    As for the carbon seat post, a very subjective opinion -- it is nice. On the three longer rides I've had on the bike (30+, 40+ and a 60+) my rear end was not complaining about the time in the saddle. The saddle is stock, nothing special, so I have to think the carbon post helped smooth out the ride, as compared to my old ride (an old mtb.). Of course, my experience is very limited and I cannot speak to the durability of the seat post . . .
    "Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body,
    but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming --
    WOW!!! What a ride!"

  11. #11
    OM boy cyclezen's Avatar
    Join Date
    Jul 2005
    Location
    Goleta CA
    My Bikes
    a bunch
    Posts
    3,011
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by stercomm
    I've got a Specialized Roubaix Triple Comp and it has Zertz inserts and the ride is definitely smoother than my Cannondale but Cannondales are known for "presenting" all the road to be experienced plus I couldn't tell you how much is due to the Zertz and how much is just having a carbon frame and forks and post and bars. I too am always leary of many of the claims around these types of add-ons.
    This is worth some "butt-gauge" testin...
    I was wonderin that myself.
    I'm loath to screw with my Roubaix Elite setup considerin the wonderous nature of the ride. But maybe it would be worth using an alloy post/seat and swapping back and forth between the carbon and alloy whilst running the same bumpy road section (and maybe include a 3rd option - Rockshox sus seatpost). Considerin I really need to back off on any hard ridin this week, it might be the opportune time to really screw things up on my bikes...

  12. #12
    Hypoxic Member head_wind's Avatar
    Join Date
    Oct 2005
    Location
    Colorado Springs
    Posts
    544
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Zertz looks like a good idea but that isn't sufficient. I have no
    experience with them.

    My 'cross bike has a low end carbon FSA (SLC?) seatpost. I use
    a cheap Al post for when I put the bike up in the workstand and
    I have compared them on the road. The carbon is smoother but
    I don't think enough to matter. It is a nuissance (sp??) to tighten
    so it won't slip and won't be destroyed. I wouldn't do it again.

  13. #13
    Senior Member
    Join Date
    Apr 2006
    Location
    Brazos River valley, south central TX
    My Bikes
    2005 Surly LHT; 2006 Surly CrossCheck with Extracycle; 1987 Schwinn World Sport as urban cruiser
    Posts
    1,298
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by dauphin
    So, even if Zertz is just a sales gimmick...what do you guys think about a carbon seat post?
    I ride with an Origin 8 CF seat post on my Surly LHT. Does it cushion the ride? Who knows? I tend to stand when I got over big bumps anyway (RR tracks, uplifted concrete & asphalt road joints, etc.) but on straight pavement, it rides quite smoothly. There are horror stories about them failing without warning (as Stapfam warns) and there are definite arguments over proper installation (greased or not greased).

    Occasionally I think about it cracking and ramming the end somewhere not intended to accept such intrusions but mostly I just ride it and like it. At this point I can't even remember why I had my LBS install it on the new bike: for weight? for road bump absorption?
    centexwoody
    They're beautiful handsome machines that translate energy into joy.

  14. #14
    Time for a change. stapfam's Avatar
    Join Date
    Jan 2004
    Location
    6 miles inland from the coast of Sussex, in the South East of England
    My Bikes
    Dale MT2000. Bianchi FS920 Kona Explosif. Giant TCR C. Boreas Ignis. Pinarello Fp Uno.
    Posts
    19,915
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by nmichell
    So when Boeing starts selling their 787 carbon fibre plane I guess you won't be flying on it
    No.


    Carbon fibre is a special material for a special use. It is not a strong material and can get damaged by abuse very easily. Hence in the hands of the average person I would not trust C.F. to be strong enough.
    When it comes to The highly technical manufacture as used in Transport (Planes, Boats, Cars) There would be certain safety margins built in like being overbuilt and testing before it could be deemed as safe. However, as an example,- What happens to the body work of a Formula 1 car in an accident? And although that is not overbuilt, it is tested and x rayed before use and F1 body work can fail without an accident.
    I used to be a glass Fibre laminator and had to repair too many Boats that have had a slight knock last year that has gradually caused a problem that is now severe, so I do talk with some knowledge.

    To trust my backside to a seat post that can fail at any time with the loose shards of pointed glass sticking upwards, is not something that I would readily do.
    How long was I in the army? Five foot seven.


    Spike Milligan

  15. #15
    Senior Member
    Join Date
    Apr 2006
    Location
    Maupin, OR
    My Bikes
    Used Marin MTB, New 6/06 Scott Contessa Speedster
    Posts
    532
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Okay, you made up my mind!

  16. #16
    just keep riding BluesDawg's Avatar
    Join Date
    Feb 2005
    Location
    Milledgeville, Georgia
    My Bikes
    2014 Specialized Crave Pro 29, 2014 Specialized Crux EVO Carbon Disc, 2012 Black Mountain Cycles Monster Cross, 2011 Specialized Roubaix SL3 Expert Compact, 2009 Salsa Casseroll, 2003 KHS Milano Tandem, 1986 Nishiki Cadence rigid MTB
    Posts
    12,750
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I wouldn't have a clue. $15 Kalloy seat posts work just fine for me. Except on my hardtail MTB where I use a Thudbuster. But that's for a bike I use for fast riding on serious singletrack with rocks and roots and dips and bumps.
    The more you ride your bike, the less your ass will hurt.

  17. #17
    Time for a change. stapfam's Avatar
    Join Date
    Jan 2004
    Location
    6 miles inland from the coast of Sussex, in the South East of England
    My Bikes
    Dale MT2000. Bianchi FS920 Kona Explosif. Giant TCR C. Boreas Ignis. Pinarello Fp Uno.
    Posts
    19,915
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by BluesDawg
    I wouldn't have a clue. $15 Kalloy seat posts work just fine for me. Except on my hardtail MTB where I use a Thudbuster. But that's for a bike I use for fast riding on serious singletrack with rocks and roots and dips and bumps.
    Ditto. That Thudbuster is expensive but for comfort- without going to full suspension, that I cannot afford, is probably the next best thing. As to the Normal MTB- Kalloy again.
    How long was I in the army? Five foot seven.


    Spike Milligan

  18. #18
    Get A Life - Get A Bike cheeseflavor's Avatar
    Join Date
    Apr 2005
    Location
    Minnesota, You Betcha!
    My Bikes
    Specialized Roubaix, Bianchi San Jose, '87 Schwinn Super Sport
    Posts
    1,042
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by seriouslysilly
    is the zertz insert necessary for safety's sake? There is a specialized frame that is currently being sold at a nice price, but is missing the zertz insert on the seat stays. The sale is just the frame, nothing else (fork, seatpost, etc).
    Would I need to put a zertz insert in it before I ride?

    I don't see how a missing insert could lead to it collapsing. Thanks!
    I'm not sure how one would fall out, but I wouldn't risk it. It's there for suspension, and I have to believe every time the seatstay flexes, the zertz deflects the energy, absorbing the shock.

    Steve

  19. #19
    Get A Life - Get A Bike cheeseflavor's Avatar
    Join Date
    Apr 2005
    Location
    Minnesota, You Betcha!
    My Bikes
    Specialized Roubaix, Bianchi San Jose, '87 Schwinn Super Sport
    Posts
    1,042
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by NOS88
    My Roubaix Pro had the Specialized seatpost. I had to replace it. Despite using a torque wrench at the proper setting the post was damaged by an off-set seatpost clamp, making it unsafe to ride. I later came to learn that the carbon in the Specialized post is especially thin. I've got over 300 miles on a new alum Bontrager seatpost with a single allen wrench adjustment. I notice absolutely no difference between the ride of the old carbon and the new alum posts. Lowering you tire pressure by five lbs is likely to make more of a difference than the seatpost.

    Disclaimer: This is just my experience. The experience of others may vary, as I suspect you'll find quickly enough.
    Good disclaimer

    I've the zertz post that came stock on my Roubaix Comp about 12,000 miles now and another few thousand trainer miles without problem. Can't say it particularly makes a difference (as I've nothing to comapare it to), but zero problems with the seatpost.

    Steve

  20. #20
    Senior Member
    Join Date
    Jun 2005
    Posts
    776
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Zertz.............

    Let me begin by saying that I am not an engineer, nor do I have any engineering coursework in my college background.

    That said.....in years past some car makers would glue a small dense block in car trunks to keep panels from vibrating, and I think that is called a 'Harmonic Damper'. Perhaps they think something with a different density can dampen some frequencies.....but I personally suspect it it hype.

  21. #21
    Senior Member guybierhaus's Avatar
    Join Date
    Sep 2005
    Location
    Oley, PA
    My Bikes
    Flat bar road bike, trail bike and MTB
    Posts
    878
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I got one of those frames. Was at a Specialized dealer on Saturday and they do not sell replacement Zertz inserts. He did mention the insert was not needed for structural strength. He knew of individuals who removed the insert to save weight.
    Last edited by guybierhaus; 01-22-07 at 11:46 PM.
    BierHaus Bertolette Road Bike, built 2007
    BierHaus SRT Trail Bike, built 2010
    Fuji Mt. Pro - 2007

  22. #22
    just keep riding BluesDawg's Avatar
    Join Date
    Feb 2005
    Location
    Milledgeville, Georgia
    My Bikes
    2014 Specialized Crave Pro 29, 2014 Specialized Crux EVO Carbon Disc, 2012 Black Mountain Cycles Monster Cross, 2011 Specialized Roubaix SL3 Expert Compact, 2009 Salsa Casseroll, 2003 KHS Milano Tandem, 1986 Nishiki Cadence rigid MTB
    Posts
    12,750
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by NOS88
    Lowering you tire pressure by five lbs is likely to make more of a difference than the seatpost.
    Best sentence in this thread so far.
    The more you ride your bike, the less your ass will hurt.

  23. #23
    Senior Member
    Join Date
    Oct 2006
    Location
    NJ
    Posts
    383
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by guybierhaus
    I got one of those frames. Was at a Specialized dealer on Saturday and they do not sell replacement Zerte inserts. He did mention the insert was not needed for structural strength. He knew of individuals who removed the insert to save weight.
    Thanks! I had hoped to be able to get inserts for the frame, but it's problably really hard to put it in the frame
    Please keep us updated on how it rides when you get your frame up and ready.


    As far as carbon, the only carbon I have is in the forks. I don't think I'll ever get a carbon seatpost because of other posts. I don't do any harsh riding, but I just don't want that on my mind. I'm not that big either, 180lbs but don't want to chance it.

  24. #24
    Senior Member gear's Avatar
    Join Date
    Sep 2004
    Location
    North shore of Mass.
    Posts
    2,131
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I'm a big boy and have had cf seat posts on both my road bikes for more than five years now. I snapped a steel bolt on one of them but the cf has held up just fine.

  25. #25
    Get A Life - Get A Bike cheeseflavor's Avatar
    Join Date
    Apr 2005
    Location
    Minnesota, You Betcha!
    My Bikes
    Specialized Roubaix, Bianchi San Jose, '87 Schwinn Super Sport
    Posts
    1,042
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by guybierhaus
    I got one of those frames. Was at a Specialized dealer on Saturday and they do not sell replacement Zertz inserts. He did mention the insert was not needed for structural strength. He knew of individuals who removed the insert to save weight.
    I really hope no one takes that as advice without checking with Specialized first. Folks used to drill their frames to save weight too, but I don't think I'd do that either.

    Steve

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •