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Left or right hand thread?

Jim LyonJim Lyon Posts: 72
edited May 2016 in MTB workshop & tech
I realise this is almost a beginner's question, but it's that long since I've done this job, I've forgotten - regarding the bottom bracket R.H. /sprocket side, the retaining collar that holds the crank in, is it left or right hand thread? At the moment it won't go either way & spraying it with lube isn't doing much good either. - TIA

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  • The RookieThe Rookie Posts: 27,747
    Not sure what the retaining collar that holds the crank in is?

    Do you mean the retaining collar in the BB, if so what BB as the drive side never has a retaining collar, it's either part of the BB or the cup for cup and cone bearings?

    Sprocket is at the back wheel by the way, it's a chainring on the crankset.
  • Jim LyonJim Lyon Posts: 72
    The Rookie wrote:
    Not sure what the retaining collar that holds the crank in is?

    Do you mean the retaining collar in the BB, if so what BB as the drive side never has a retaining collar, it's either part of the BB or the cup for cup and cone bearings?

    Sprocket is at the back wheel by the way, it's a chainring on the crankset.

    JL- Well. a chainring is just a bigger sprocket, but that's not worth arguing over. ::)

    Like I said, this on the R.H.S. inside of the chainrings. The bike is a 1997 Marin Mount Vision & the crank screws into the bottom bracket then an alloy collar goes on after that the collar is wound in until it butts up against the side of the bottom bracket, i.e.it's external yo the bottom bracket, sitting beside it, on the crank. And when it's all tightened down, there's about 2 threads on the crank tube showing outside the collar.
  • The RookieThe Rookie Posts: 27,747
    Your going to have to post a photo, I think you are talking about a self extractor collar in the crank arm that doesn't need to come out at all, but how anything attaches to the crank and butts up against the bottom bracket (on the other side) you've lost me on!

    If it's a self extraction collar you just undo the bolt holding the crank to the BB axle and the head of the bolt bears on the collar and pulls the crank off for you.

    http://www.parktool.com/blog/repair-hel ... extracting
  • RightarmbadRightarmbad Posts: 216
    It is a standard threaded BB.
    Left hand thread chain side, right hand thread non chain side.

    It sounds as though you have an adjustable chainline BB so it has a lock ring on both sides.
  • Jim LyonJim Lyon Posts: 72
    It is a standard threaded BB.
    Left hand thread chain side, right hand thread non chain side.

    It sounds as though you have an adjustable chainline BB so it has a lock ring on both sides.

    Going back to my original question, I've now got it. - Whichever side of the bike you're on the thread is the opposite.


    JL - You're right about the crankshaft, it's an adjustable one with a lock ring on both sides so you can offset it in either direction to adjust the chain line. Not knowing that, I've just set it up in the middle ( so there's an equal amount of thread sticking out from the bottom bracket ) & so far that's been OK. So, does adjusting it make any
    significant difference?
    Being my best bike, my Marin tends to get used as a "fair weather" bike so the mileage isn't that high for it's age. However, early on I came across a problem which made me think that Marin were trying too hard to make it a sports bike i.e. they fitted alloy nipples to the wheel spokes. Trying to solve the problems that caused, I even tried loctiting the nipples to the spokes but eventually had to accept that any alloy nipples I could get were simply not up to the job. So I replaced them with stainless steel ones to match the spokes & thus prevent the possibility of problems from electrolytic corrosion. Problem solved.
    Now, with the lock rings on the crankshaft, I'm starting to have problems undoing them. The most probable cause is that the lock rings are made of alloy, & having been off & on only a few times, the alloy slots are already starting to spread, & I now suspect that I'm going to have to replace them with steel ones. So, do you know if, regardless of the material they're made of, are all lock rings a standard size? And I suppose I can't buy them separately? If so, a heads up would be real nice. - TIA
  • cooldadcooldad Posts: 32,904
    You adjust it for optimum chain line.
    Without knowing the details of the BB, nobody knows.
    I don't do smileys.

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  • Jim LyonJim Lyon Posts: 72
    Well, after a long rummage around, I've found some stock steel lock rings for a rigid framed Trek 820 . As might be expected, they're right hand thread & fit the left hand side. So, the big problem is going to be the right hand side, as obviously, an alloy lock ring won't last forever!. And which will expire first, the alloy RHS collar, or the crank, I don't know. Getting some made up specially in steel is going to be difficult. So, as sooner or L8R, I'm going to need a new crank anyway, does any firm do these adjusdtablr cranks where the lock rings are in steel? And where's the best place to get them?- TIA
  • Jim LyonJim Lyon Posts: 72
    Well, I've had a flog round Google & Ebay to little avail. For future reference, can anybody recommend a good quality -reasonable value for money adjustable BB, suitable for a Marin "Mount vision" MTB?
  • The RookieThe Rookie Posts: 27,747
  • Jim LyonJim Lyon Posts: 72
    The Rookie wrote:
    Just fit a Deore HT II setup, chainline can be adjusted (if needed) by swapping spacers around.

    Thanks for that . :)
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