Bicycle Mechanics - Lock Rings on BB's
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Hi again *slowly becoming regular in here!!*
Is it essential to have two lockrings on a BB?
I have had a titanium BB inserted into my Kona, but it's missing one of the lockrings. The mechanic wasn't too sure wether or not it would infact need it.
Thanks for any advice.................................Rich :)
I don't think so. Normally you would have a fixed cup which is tightened up to the BB shell, and an adjustable cup with one lockring which is adjusted up to the shell when the adjustable cup has been adjusted-- if that makes sense.
This doesn't apply for Shimano sealed BB's in which case they are both effectively fixed cups.
Amen for that! I'll let you know if there's any problems with it!
[i]This doesn't apply for Shimano sealed BB's in which case they are both effectively fixed cups. [/B]
How could one adjust the bearing preload with two fixed cups? The only systems I have seen use a fixed cup on the drive side and an adjustable cup-plus-lockring on the left side or a pair of adjustable cups, each with its own lockring. The latter configuration allows the user to adjust the chainline a bit, if necessary.
Look at your right-side cup. If it has a flange that tightens against the BB shell, no lockring is needed (or possible). If it is threaded all the way, with no flange, as on most left-side cups, it needs a lockring.
I see what you mean, but my Shimano Un 52 BB has a fixed cup on one side but no lockring on the other, rather another threaded cup with a flange. It has (I think) roller bearings and in 3 and a half years of heavy use hasn't given any trouble. No lockring.
As it is a sealed unit, no need to adjust preload (I think) but I remember I had to give the width of the BB shell when buying it. Previously I have had Campag, TA and Mavic BB's, all adjustable.
My Flying Scot has an adjustable BB (Campag) and the shell has a grease nipple!
the nice people at Bike Hut have fitted the BB, and say there shouldn't be a problem with it...
The next thing now is that it's a 120mm axel length, which may not fit my new Race Face cranks...
Oh, life is one big merry-go-round.....
To answer your question - No
However depends on the BB. All new BB do not require this and are basicly screwed on. Older models used lockrigns to make sure they would not come loose. Also some models were adjustable so you can adjust the BB to either side.
As you already noticed differnt cranks require different lenght axles.
Now companies make it much easier for consumers. However customizing is a bit harder. I mean buying different lenght axles. Still some older BBs are offered in many different lenghts.
I also bought a Raceface BB (axel length 110mm) because the new cranks are low profile and may not fit on a 120mm axel....
Just hoping now that it fits onto my Kona...
Cheers for the advice. :)
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