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EVO386 BB self diagnosis.


Fat Boab

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I have one of those annoying noises which I think is BB related. Diagnosis so far include:

 

1. I've spun the cranks by hand, with the chain removed to check for dead-spots, grinding etc. Nothing.

2. Pushed and pulled the pedals laterally across the frame to look for play. Nothing.

3. Pulled the cranks and checked the bearings for lateral play with my fingers. Nothing.

 

Before a trip to my LBS, what else could I check? Thanks in advance for the help...

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i once had a Sram crank that developed a tick noise.

 

remove the crank and try bend or twist it against the spindle

it was the arm that was ticking and not something that was repairable 

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Does it happen whenever you pedal, or only when standing? Might sound really dumb, but I once had a BB creak that turned out to be headset related (the noise happened only when I was standing).

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I have one of those annoying noises which I think is BB related. Diagnosis so far include:

 

1. I've spun the cranks by hand, with the chain removed to check for dead-spots, grinding etc. Nothing.

2. Pushed and pulled the pedals laterally across the frame to look for play. Nothing.

3. Pulled the cranks and checked the bearings for lateral play with my fingers. Nothing.

 

Before a trip to my LBS, what else could I check? Thanks in advance for the help...

 

Chainring bolts.

 

Those little bastards love making ticking sounds if they are 0.0000000001Nm away from their recommended torque. Remove, locktite, replace, torque.

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Seated or standing. And any gear or perceived torque, unless I pedal very gently, then the noise goes away.

 

Does it happen whenever you pedal, or only when standing? Might sound really dumb, but I once had a BB creak that turned out to be headset related (the noise happened only when I was standing).

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Had this issue on my son's bike, to cut a very long story short, bought this BB from Aliexpress.

 

https://www.aliexpress.com/item/32899151818.html?spm=a2g0s.9042311.0.0.27424c4dedvuoo

 

Problem solved. I used the Aramex shipping option from Hong Kong, didn't want to wait for the normal shipping which takes too long. Ended up costing about 800 to 900 Rands total.

A screw together BB is my go to solution for all press in BBs.

 

If you buy a PF bike do yourself a favor and before you ride it toss the PF BB and pop a "screw together" BB in. It will save you heart ache, money and pain in the long run.

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Seated or standing. And any gear or perceived torque, unless I pedal very gently, then the noise goes away.

 

pedal perhaps? or even cleat interface. I had this on my left shoe once. the other time i was convinced it was my bb and it turned out it was my saddle rails where the went into the housings. some q20 in there made that problem go away. 

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Does your BB386EVO bb use 6806 bearing sfor 30mm axle, reducer spacers to get it down to 24mm or does it have MR2437LLS bearing for 24mm axles?

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BB creaks are hardly ever the BB. If you've checked it and it's the bearings are smooth and you've reassembled the crank properly then check pedals, headset, hubs, skewers, seatpost, seat rails, cleats...

 

If none of these solve the problem then it may be the pressfit interface - but it's pointless destroying a BB before you've eliminated potential creaks that are easier and less destructive to fix.

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BB creaks are hardly ever the BB. If you've checked it and it's the bearings are smooth and you've reassembled the crank properly then check pedals, headset, hubs, skewers, seatpost, seat rails, cleats...

 

If none of these solve the problem then it may be the pressfit interface - but it's pointless destroying a BB before you've eliminated potential creaks that are easier and less destructive to fix.

 

 

Creaks I agree, but clicks usually do emanate from the BB.

 

I'm going to assume we're dealing with a MTB because details on the bike itself are about is thin as Bikehub becoming a place for reasonable doping discussions....

of ocurse a BB360EVo is more popular on a road bike but we'll cover that was well.

 

I find the 6806 bearings, especially the Enduro variety to make clicking sounds well before the bearing has worn out. Its kind of an early warning that they want some life extension by grease. The plastic cages don't help matters.

Often you can only tell if those are going when you apply load to them. A workstand check doesn't reveal much unless they are already shot to hell. If the bearing is worn and there's little preload on them as a result of wear then the crank will feel smooth till load is applied. If the crank has a bearing preload adjuster, try dialling in some more preload and see if the noise goes away. Yes? then the bearings are on their way out. 

No? then its likely not the bearings themselves but maybe the bearing in the BB shell or plastic /metal cup is dry. 

Remove the crank and apply inward pressure to the bearings. If it feels rough with or without pressure  then its shot. 

 

Clicks could also indicate a pedal bearing is going or even a lower pivot bearing which you won't hear when chattering down the trail. Check the rear triangle for unwanted play in the bearings.

if your cranks uses a Direct mount SRAM 3bolt interface its unlikely to creak but stranger things happen. Easy to check, apply grease to the interface and refit. Locktite the little M4 bolts inplace.

If its a cannondale Hollowgram interface or raceface Cinch interface then check the lockring torque.

 

Chainr ring bolts would apply to a 2x crank. Check those.

Headset bearingsare easy to check. If the bearings feel rough when turning the bars side to side quickly then that could be your problem.

 

How are the front wheel bearings feeling? Spin the wheel and place one hand on a fork leg. Does it feel rough with high spots? could be one of those bearings are shot.

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Hang on okes...headset felt loose (swore I checked that already...) so have tweaked. Test ride later this arvie...will feedback.

 

PS road bike!

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Seated or standing. And any gear or perceived torque, unless I pedal very gently, then the noise goes away.

 

I once had an issue similar to yours not too long ago, although on an MTB with single chainring. 

 

Whenever I applied pressure to pedal, I heard this noise which sounded like my chain was rubbing up against something - like a slight grinding noise. With no pressure applied (spinning freely), it was gone.

 

After trying everything (swopping chains with my other bike, tightening up chainring bolts, swopping rear derailleurs, new derailleur pulley wheels, swopping BB's, servicing pedal bearings, tightening crank arms etc...), I eventually found the culprit to be the chainring itself.

 

Although the chainring was noticeably flat when placed on a level surface and no visible bent teeth, I decided to swop it out with a spare chainring of mine....and it solved the issue.

 

The issue turned out to be "chain suck", not because the chain or chainring was dirty, but purely because the chainring bent slightly when pressure was applied to pedal. This caused the chain line to shift off axis to the rear derailleur, resulting in the chain rubbing up against the derailleur cage.

 

Still not sure how the chainring manages to fail this way - I probably bashed it on a downhill run without knowing. 

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Creaks I agree, but clicks usually do emanate from the BB.

 

 

Not saying it's impossible - I had a BB click on my bike the other day - but 9 out of 10 BB noises that come in through my door are from elsewhere on the bike. 7 of them are pivots, which obviously don't apply here, but I tend to eliminate anything that doesn't need destroying before I reach for the hammer.

 

The number of loose headsets, pedal bearings and axles is remarkable.

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Many thanks to those who gave their wisdom and knowledge.

To those who suggested the root cause was...headset. Well it was loose but not the cause.

Chain-rings? Could have been tighter but also not root cause.

Saddle? Bingo! Just enough lack of tension in the seat post bolts to allow the saddle to creak.

 

Many thanks again...long live BikeHub!

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