Bottom Brackets (ST...
 

[Closed] Bottom Brackets (ST) lifespan shortened by Single Speeding?

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After about a year commuting SS I notice a 'tinging' coming from either by BB or chainring. About a year ago I was so annoyed by it I swapped out both (failing to identify the culprit in the process!)

It occurs mostly when right crank is between 5-7 o'clock and happens sometimes when not pedalling but crank in same position making me think it's the BB.

I suppose a year from a £10 component is good value, but I used to get a few years from square taper BBs running gears. Are they more susceptible to uneven loads or more wear when pushing singlespeed? It may just be due to lack of maintenance being my commuter/hack? Am I worth spending a bit more for a better sealed unit? UN73?


 
Posted : 10/07/2014 10:24 am
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OP i've got a UN-53 b/b which is now about 14 years old and still spinning smoothly...its never been maintained and has been used on 4 different frames in that time...i would expect a sealed bearing unit like a UN-73 to perform in a similar manner.
for what its worth CRC are selling the UN-55 for £12.50 which is a good deal


 
Posted : 10/07/2014 11:09 am
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As above. I've never had less than 5yrs from a UN-5x BB on my SS-commuter and my SSCX.


 
Posted : 10/07/2014 11:10 am
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Think it's a Truative BB in there just now.

I'll give everything a strip down, clean and replace with a shimano sealed unit.


 
Posted : 10/07/2014 11:21 am
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It's all about the chain tension. If it doesn't have a tiny bit of slack at all positions the bearing's won't last long. It's tempting to try and get the chain tight on single speeds but it'll kill the bearings.


 
Posted : 10/07/2014 11:47 am
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It's all about the chain tension. If it doesn't have a tiny bit of slack at all positions the bearing's won't last long. It's tempting to try and get the chain tight on single speeds but it'll kill the bearings.

+1

Puts too much pressure on the bearings


 
Posted : 10/07/2014 11:49 am
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Lucky to get a year out off a shimano ht2 on my SS scandal.


 
Posted : 10/07/2014 11:52 am
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I'm running a vertical dropout frame with tensioner so don't think it's to do with chain tension.

Thought it was my welgo v8 copies yesterday so stripped them down and re-packed with grease but no change...glad I done it though!


 
Posted : 10/07/2014 12:25 pm
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UN 5X normally last 1-2 years for me, but then I had a brand new one die over the course of a single 24 hour race once, admittedly it was a filthy filthy race but it is possible I had a badly sealed duffer.


 
Posted : 10/07/2014 12:34 pm
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If its just making a noise but the BB feels smooth, take the cranks and BB off, clean the tapers, clean the threads on BB & frame, grease / copper grease the threads, reassemble and a thin wipe of grease on the tapers, should be quiet after that!


 
Posted : 10/07/2014 1:06 pm
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So far I've killed two sets of rear wheel bearings in two differnt sets of wheels. So far bottom bracket is surviving.


 
Posted : 10/07/2014 1:44 pm
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I get this clicking on my SS. Turns out it's the pedal spindles/cranks interface. Bit of GT85 sorts it.


 
Posted : 10/07/2014 1:54 pm
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Thanks for the heads up on the CRC offer


 
Posted : 10/07/2014 2:01 pm
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ticking/clicking is generally dry threads or loose components. Wear is recognised by play in BB bearings.

Many people get the former wrong, they replace the BB and the sound goes - but that's because the new BB has been installed correctly - re-installing the old one would have done the trick.


 
Posted : 10/07/2014 2:09 pm
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Already second hand Chris King been in my SIR.9 for a few years now. Annual grease purge & still spinning like new. Wouldn't pay full wack for one though.


 
Posted : 10/07/2014 6:16 pm
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I get about a year to 18 months for XTR hollowtech BB's (infact I now change frames more often than BB's!), never go more than a year out of UN-73 BB's despite the rose tinted glasses.

I killed my CK BB in about 3 years, although I never greased it and it died trying to get the cranks out and they took the inner race with them rather than developing play depite the bearings being bone dry.


 
Posted : 10/07/2014 6:30 pm
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It's all about the chain tension. If it doesn't have a tiny bit of slack at all positions the bearing's won't last long. It's tempting to try and get the chain tight on single speeds but it'll kill the bearings.
+1

Puts too much pressure on the bearings

What about when you pedal? The force on the drive side of the BB while pedalling is considerably more than a slightly too tight chain.


 
Posted : 10/07/2014 6:57 pm
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So... Removed BB, found out it was a shimano un26. BB seemed smooth, no click or grindy so cleaned everything then re-greased and replaced.
No click/tingy noise now. Maybe some grit in BB threads or it was loose.


 
Posted : 23/07/2014 4:10 pm