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 K2 Proflex-5000 frame torsion
Does anyone else out there have the same problems I have had with K2 proflex frames? Mine often seems to give out in the rear when I lean into corners (a VERY bad feeling, though technically not too dangerous). I have checked the rear wheels and they are tight, the carbon fiber swingarm is what twists. Is this normal? Otherwise I love this bike.

Kudos to whoever redesigned this sight so that posted messages AND their replies can be viewed at the same time! Now why didn't we think of that sooner?
Posted by Matno a 27 year old Die-hard Enthusiast riding a K2 5000 from Utah on 01/08/01

Responses: (1) (2)

  •  Re: K2 Proflex-5000 frame torsion
    i've ridden k2's and proflexes for many, many years. when the design was changed over from the world cup frame styles that included the rear strut, rear torsion was one of k2's acceptable ride changes that came with more travel and plushness. the strut kept the rear firm because of the anchoring below the seat post but the now free carbon swingarm is prone to torsional stresses around the main pivot. it's taken me a while to get used to it, now i won't go back.

    you may want to check in and post your comment/question on our temporary k2 tech forum located at: http://members3.boardhost.com/K2Tech-2/

    "Old Proflexer"
    k2bikes.com - tech forum
    Posted by Old Proflexer a 49 year old riding a K2 4500 Pro Carbon S w/Discs from Mission Viejo on 01/09/01

    Responses: (0)

  •  Re: K2 Proflex-5000 frame torsion

    I saw your posting on here and thought I would take the opportunity to inform you of my opinion on the carbon bike.

    Although the 5000 is alloy.... I am sure that when I tested a 5000 I too felt the flex in the bike.... compared to my 957..... but, after rebuilding my 957 into the Oz frame I also had this lean feeling that you describe.... to remedy this..or rather try to eliminate possible causes..I tightened the wheels a fair bit..... so that the spoke tensions showed between 1.00mm and 1.20mm deflection on the mavic gauge... tight in other words...

    This made it better... but it is still there... I ride around it now... seems ok.

    The only other weakness of the bike was the lack of disc brake tabs..... but I had discs on my Proflex 957 and used the same method to fit them to my Oz...... the solution is so popular that even the other guy (Old Proflexer)that replied to your posting bought one from me (to fit discs to his bike, I assume).

    I only made an adapter for the rear as I use a Marzocchi fork on the front.
    Much better..IMHO

    There are pictures on my webpage, the URL is below... It is not a very
    professional webpage, just a hobby thing that I made a few years ago.... but
    there are pictures there all the same. The picture on the webpage is of my
    Carbon Oz bike, this has the same swingarm as your bike, but for the record
    I also have adapters available for the 857 and Animal type swingarms too.


    Take it easy,


    Ps. If you are interested in ordering an adapter, you can do so either by
    ordering direct from me.. or by buying online with credit card payment via
    click on the link marked
    'Products' for more information there.

    Posted by Mike billett a 33 year old Racer riding a Pro~Flex/K2 Oz carbon from Sweden on 01/09/01

    Responses: (0)

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