Campag 11S jockey/tensioner wheels - float needed or not?

rjkflyer
rjkflyer Posts: 85
edited June 2013 in Workshop
In 2009, the Record RD had BOTH wheels with ceramic bearings (RD-RE-800), but the Super Record had tensioner (bottom) with CULT and top (jockey) with bronze sleeve (RD-SR500) which allows float.

From 2010, both R and SR share the 'mixed' set (RD-SR500).

So 2009 R didn't need float but 2009 SR did?!

And then 2010 on, they all did?

Anyone got a view on the pros and cons here?

Question: anyone tried a SR CULT tensioner in the top jockey position?

I ask all this as, although we can debate whether the friction matters, there's no question that the losses from the sleeve bearing are some 20x that of the ceramic. So, the issue is do we need the float or not?

Comments

  • drlodge
    drlodge Posts: 4,826
    I wonder if the float is a design feature to cater for imperfect trimming of the RD. If the RD is slightly out, then the top jockey wheel can move a little via the float, which makes the chain wear less. Of course I would prefer ceramic bearings and no float since my RD is always perfectly trimmed ;-)
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  • rjkflyer
    rjkflyer Posts: 85
    Yes float is undeniably to allow for some tolerance, but I'm curious as to why this 'need' came and went within group sets that are functionally identical.
  • rubbernekker
    rubbernekker Posts: 112
    Pure speculation, but Shimano regularly drops experiments into groupsets where you would not normally expect them, perhaps with 11 speed being so new at the time they questioned the need for float with such narrow spacing. Sometimes the only way to discover the effect of a change is to send it out into the real world. As it is, it seemed it didn't work.
  • dennisn
    dennisn Posts: 10,601
    My thinking is that whether it floats or not it should be replaced with it's EXACT original equipment replacement part. Doing a repair and only thinking that you know what you're doing or rationalizing that this or that part will work "just fine" without really knowing is not the best of ideas. Original equipment parts are the parts that are already on the item and designed to work with it. Doesn't make a bunch of sense to me to "try" something else.
  • rjkflyer
    rjkflyer Posts: 85
    To some extent I agree with dennisn - and am not trying to 'out-think' Campag, but equally I AM willing to be thoughtful and experiment based upon sensible judgement and experience.

    The fact that Campag used a ceramic top bearing means to me I it is worth considering. It might be that Campag's decision to go 'back' to upper wheel float is to assure the 99% of people who aren't obsessive about maintenance get acceptable shifts. So, given i AM prepared to be obsessive, I will try sensible alternates.

    I know two people, both fastidious maintainers, one Shimano, one Campag, who have gone aftermarket ceramic and have no indexing problems.
  • thegreatdivide
    thegreatdivide Posts: 5,807
    I run Token ceramic jockey wheels on my 11-speed Record rear mech with no problems at all.

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