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BB30 Grease

Discussion in 'Bicycle Mechanics and Repairs' started by JPBoothy, 6 Feb 2018.

  1. JPBoothy

    JPBoothy Well-Known Member

    Location:
    Cheshire
    Hi All,

    Apologies for bringing-up the dreaded subject yet again but, I am trying to use a better quality of grease to try to keep the water out of my BB30 bearings and was wondering if a Marine grease would be too thick for this task. Any opinions on this ?

    I know that the BB30 gets a terrible review from most members (except the lucky few!) but, as I have got two Cannondale's with it fitted to them already, I have resigned myself to a life of regular maintenance. However, if I can use a better quality grease to increase the time between my service intervals that would be great.
     
  2. mustang1

    mustang1 Veteran

    Location:
    London, UK
    I can't answer your Q but I have a cannondale and not experienced problems; I get it serviced regularly though .
     
  3. gbb

    gbb Legendary Member

    Location:
    Peterborough
    I assume you'e talking about flipping the seal off the bearing itself, inserting some grease and refitting the seal...if so, it's possibly what I'd do and marine grease will be as good if not better than most other greases...but there will be increased resistance to turning the cranks...whether it effect performance or youd notice is argueable, but it would certainly resist ingress of moisture better.
    My own preference with outboard cups is (assuming you can and have a method to remove them from the cups, to remove the often cheap and nasty original bearings and fit SKFs or similar, there's a world of difference in quality . I asssume its do-able with BB30 as well.
     
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  4. OP
    OP
    JPBoothy

    JPBoothy Well-Known Member

    Location:
    Cheshire
    I think it is hit and miss as, I am on my third Cannondale and have never experienced anything too serious just noises really. It starts with an annoying creak that you can't pin-point as it sounds like your stem or seat post may not be tight enough and, eventually turns into more of a grinding sound. I think the main issues are water finding its way into the grease itself and breaking it down and/or, whether or not the bearing is seated well in the frame itself. I am going to try 'carefully' removing the seal and re-packing the balls with new grease but, if that doesn't work then I have read that adding a drop of a type of Loctite 'should' the bearing firmly when you press it back into the frame.

    I am a Cannondale fan though so I wont be letting the BB30 put me off. I suppose it is the same with anything, some people have good experiences and some people only have bad.
     
  5. OP
    OP
    JPBoothy

    JPBoothy Well-Known Member

    Location:
    Cheshire
    Thanks for the advice. I suspected there may be more resistance with the thicker grease but, if it is marginal then that's not a problem. However, if it felt like I was trying to peddle up a hill in a big gear then that would be a different matter :sweat:
     
  6. OP
    OP
    JPBoothy

    JPBoothy Well-Known Member

    Location:
    Cheshire
    Now that I have dismantled my crank a few questions (perhaps stupid ones but, what the heck!) have come to mind.

    (1) When the spline/spindle is inserted through the bearings what stops it doing the turning and the bearings staying still? Is it down to the tight tolerance that sort of 'wedges' it into the bearing to ensure that the bearing is doing the work? Would the application of some loctite ensure the right part is always doing the turning?

    (2) Could the mating surface on the spline/spindle ever become worn to the point where there would be minimal contact with the bearing?

    I'm sorry but, I was the kid who asked lots of questions in school :blush:
     
  7. Tangoup51

    Tangoup51 Well-Known Member

    Location:
    Leicester
    IF i'm thinking this correctly, when you push the spindle through the bearings and tighten the opposing crank-arm down,- It "pulls" the crank arms together, (like the headset) and Thus squishes them against the bearings (like you thought)

    Anddd No, the mating surface on the spindle can't become worn because it doesn't move against something, it moves with something - the thing that moves against something is always the bearing against the race, which subsquently is the wearing part.


    - Also, like you'd probably imagine, if you overtighten the 'squishing' force you will get less smooth bearing rolling and increased wear. So make sure you tighten your cranks up properly, which is typically fairly snug with a good size allen key but nothing to get a cheater bar out for

    No question is stupid if you feel the need to ask it ^_^


    -- Edit, In reply to your main question however, I recently serviced my PF30 bearings without taking them out of the frame, I used this lithium grease, yellow looking stuff, very thick but ive used it for all sorts.

    I recall asking an old guru at my bike shop whom i worked with if the stuff was any good and his answer was "It covers just about anything"

    So since then i've just used that stuff. Ages well, doesn't like water though, but works for Yonks when you keep it dry, good bottom brackets like yours and mine have decent seals anyway, so I tend to not care about weather resistance.

    It doesn't matter how thick your grease is, if you pack it well and tighten it down, the excess will squish away and you're left with all you need.

    Just don't fall into the trap of using "bike specific grease" which is priced stupidly high - i've used stuff advertised for industrial and car related bearings, which you can buy in bulk and do the same job in the same circumstances.

    Remember, bicycles are a vehicle not a vintage clock. We don't need any specific products.

    Keep in mind what I said about tightening too hard though, that can cause you to be changing grease and bearings too much too. (Fresh grease always causes noise especially when packed hard.)
     
    Last edited: 8 Feb 2018
  8. OP
    OP
    JPBoothy

    JPBoothy Well-Known Member

    Location:
    Cheshire
    Thank you very much for your advice and tips, it is much appreciated. The tightening of the cranks to make them snug inside the bearings makes sense to me now. Do you think a drop of Loctite 641 to ensure that there is no chance of movement between the mating surfaces is necessary or overkill? I have read that a drop inside the cups if pressing new bearings into the frame can prevent creaks though. Or again, is that overkill?

    What did you mean by new grease causing noise. Isn't that what we are trying to get rid of?
     
  9. Tangoup51

    Tangoup51 Well-Known Member

    Location:
    Leicester
    No problem.

    Hmm, realistically I'd say it's not worth it. On the basis that the creak you're hearing is probably not coming from the cups. Whatever your manufacturer saw fit to put on those cups before slamming them into your frame, you want to copy them. I don't think they used loctite, though I know loctite is harmless in this purpose but I'm going to bet it won't change anything.

    BB30 has a sticky reputation and it makes people paranoid, I always assume the noise comes from elsewhere, headset, crank-ring bolts, seatpost, pedals, etc.

    And if you pack grease thick, it will have a very "rumbly" feel to it, and may cause alot of static grumbling noise when running them. Though it usually settles after 10-15 miles, it's just because while grease is a lubricant, when packed thick it does offer resistance.

    As for the click, clonk, creak noises from the BB the chances i'd say are an overtightened crank-arm and water-washed bearings.
     
  10. Milkfloat

    Milkfloat Veteran

    Location:
    Warwick
    I have had to use loctite bearing compound to stop creaks on my BB30A frame. The creaks appeared within 200 miles and the shops solution of grease on the bearing/shell interface lasted about another 100 miles. Since the loctite, no noise whatsoever.

    Regarding the spindle/race interface. This is my spindle after about 5K miles with just a bit of grease on it 300 miles into the life of it.

    20170904_093116084_iOS.jpg

    As you can see - barely any wear.

    However - as you can see in this post @Globalti had a very different experience. Next service, I suspect I will put a tiny bit of loctite on the axel.

    This is the informative thread https://www.cyclechat.net/threads/cannondale-bb30-bottom-bracket.196684/
     
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  11. Globalti

    Globalti Legendary Member

    Not really a different experience; the timings are identical to yours. Your spindle has a grey finish, which is beginning to be worn away by the fretting of the spindle inside the inner bearing race. The wear is also on the non-drive side, which is not stabilised by the chain. I believe the creaking is caused by the microscopic bending of the spindle within the inner race.
     
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