Bottom Bracket

[STEPHAN DAVIS]

Trying to get my bike sorted for trip to France but i've developed a creaking noise coming from the bottom bracket area. Sound only seems to be when i put more pressure on the crank - especially strong when I'm out of the saddle. Tried some different pedals but still there?

Many thanks

 

[I like Skol]

Could be numerous things. The most obvious would be to check the crank bolts are sufficiently tight. Also worth dropping the chain off the chain rings and seeing if the unloaded crank spins smoothly.

 

[STEPHAN DAVIS]

I've taken all the crank bolts out and greased and tightened them. The current BB is a 'shimano-tiagra-4500-bottom-bracket-cup-set'. As i'm about to embark on a 800 mile road trip across France i'm thinking it better to replace it for peace of mind? Is this a newbie job or one for the LBS? I also wondered if this would be a decent replacement as i can't find a 4500?

http://www.wiggle.co.uk//?s=Shimano Tiagra 4500 Bottom Bracket Cup Set/?bvExpandQuestion=174050

 

[fossyant]

In or out of saddle. In check saddle rails. Also check bars, stem and the bloody headset compression split ring, that little bugger can cause all sorts of noises, grease it up.

 

[STEPHAN DAVIS]

Worse when i'm out the saddle or going up hill. Noise is more audible under pressure - you can hear it as the pressure is applied to pedal.

 

[fossyant]

You are best going throuh the main components first and regreasing and fitting.

 

[fossyant]

Get the cranks and pedals and bb out first

 

[400bhp]

as above - a simple test. Stand off the bike. Put the pedal arm at the downstroke position. Place one foot pointing towards the bike on the pedal and press down hard. If it creaks then it's likely it's the bb.

 

[400bhp]

Tiagra bb's, from experience, appear to last about 4-5k miles (riding in all weather).

 

[STEPHAN DAVIS]

Just tried the BB test and nothing. I've been presuming its something to do with the BB because it only happens under strain. Guessing a lot of other parts are under strain on the down stroke also. Will loosen off all the new mudguards and panniers tomorrow and see if its still there.

 

[fossyant]

The test dont work. Remove the lot and refit with new grease. It even happens on the old skool square taper cartridge bearings if they are not initially fitted right. BB areas need to be re-done on most bikes if new as most are shoved together without the right amount of grease. Then you know it is done right

 

[fossyant]

As you take out the bearings, if they feel rough, replace

 

[STEPHAN DAVIS]

Update on bottom bracket. Friend of mine has just taken the crank out and one of the bearings is on its way out. The noise has stopped but decided to get it sorted sooner rather than later.