Bottom bracket creaking noise-help

[Hurricane]

I am having problems with the bottom bracket (Crank) on my Synergie Cruiser. It makes creaking and clicking noises especially when under load. I have tried lubricating it but it is still the same. I suspect water has got in and rusted the bearings. There is a bit of movement in the shaft.

Does anyone know if it is a sealed unit in the Synergie which is now Alien or is it possible to remove it and replace the bearings.

Any help would be greatly appreciated. I have ordered a crank and bottom bracket removal tool for the anticipated job.

 

[Pedalo]

Not sure if it helps but I've had a number of creaks recently which on a couple of occasions I thought were bottom bracket issues, but each time turned out to be something else.

These were:
i) Creaky pedal cages. Screws needed tightening.
ii) Creaky seatpost. Just took it out and put it back in again.
iii) Creaky water bottle cage. (Mine holds a 2Kg battery). Just needed to tighten the screws.

 

[Blew it]

So far as I can tell from photos of the Cruiser, it's fitted with a sealed cartridge bottom bracket, as many of the Synergie bikes are. It is rare for these to need replacing, except after tens of thousands of miles.

The most likely cause of the creaking is the pedal crank arms need re-tightening, you will need a M14 thin-walled socket to do this.

The next place to expect creaking with each pedal stroke, is the height adjustable Ahead stem and the two bolt cap securing the handlebars to it. when pressing hard on the pedals, the rider pulls upwards on the bars, any looseness in this area will cause creaking in-time with each pedal stroke.

Finally, The Cruiser is fitted with a threaded head-set, so check the tightness of the expander bolt in the top of the ahead stem, usually M6, it may be hidden under a plastic cover.

Have Fun
Bob

 

[Hurricane]

Thanks for the reply Pedalo and Blew It. I will go and see if the handlebars etc are suspect although I have noticed that if I back pedal by hand it feels a bit "Notchy" and sounds very gritty.

I wondered if maybe the bottom bracket just needs tightening.The bike has done about two thousand miles Once I have the proper tools I will be able to check it.

Thanks again

Alan

 

[Mussels]

I wondered if maybe the bottom bracket just needs tightening.The bike has done about two thousand miles Once I have the proper tools I will be able to check it.

If it's loose you will be able to wobble it by hand easily, if you can't then it isn't.

 

[John L]

Hi Alan

I was convinced that the crank on my bike was creaking until I happened to adjust the saddle. I tightened everything up and on my next spin there was no more noise. I assumed that when I pressed on the pedal the creak was from the crank but the weight shift on the saddle was the cause

John

 

[Hurricane]

Good idea John. I once had a squeaking saddle. Every time I went up a hill I had this squeak. Only found it when I changed the saddle.

I do think this is the bottom bracket though. I have checked the handlebars and can't find anything wrong there.

With the bike sitting stationery and on the side stand I can take hold of a pedal with my hand and back pedal. I can feel the bearings clunking.

 

[Blew it]

It appears your BB is the traditional cup and cone type, not a sealed cartridge as I first thought.

From experience, It is only the caged ball bearings that need replacing. These can be purchased from your local bike shop. Ball bearings are hardened and highly polished on their outer surface only. It only takes a small amount of grit to start what is known as de-lamination, where this outer layer starts to chip off.

The cups and crank axle are hardened all the way through and usually survive to be re-used. When reassembling, pack the bearings and cups with plenty of general purpose Lithium grease such as Castrol LM. This can be purchased from car accessory shops in 500 ml tubs, the small tubes sold in bike shops is nowhere near enough.

For a few miles after reassembly, you will need to wipe away the grease which oozes out, this is no bad thing, if grease is oozing out, water and grit can't get in. The new bearings will bed in quickly and may need re-adjustment after a hundred miles, likewise, the crank arms may need re-tightening on their tapers.

Have fun
Bob

 

[Hurricane]

It appears your BB is the traditional cup and cone type, not a sealed cartridge as I first thought.

From experience, It is only the caged ball bearings that need replacing. These can be purchased from your local bike shop. Ball bearings are hardened and highly polished on their outer surface only. It only takes a small amount of grit to start what is known as de-lamination, where this outer layer starts to chip off.

The cups and crank axle are hardened all the way through and usually survive to be re-used. When reassembling, pack the bearings and cups with plenty of general purpose Lithium grease such as Castrol LM. This can be purchased from car accessory shops in 500 ml tubs, the small tubes sold in bike shops is nowhere near enough.

For a few miles after reassembly, you will need to wipe away the grease which oozes out, this is no bad thing, if grease is oozing out, water and grit can't get in. The new bearings will bed in quickly and may need re-adjustment after a hundred miles, likewise, the crank arms may need re-tightening on their tapers.

Have fun
Bob

Thanks Bob for your reply. This is good news. I was hoping the bearings just need tightened or cleaned. In the past I have cleaned bearings in Petrol to remove dirt. I have a tin of grease which is a good repellent of water. Hopefully the removal tools will arrive in the next few days and I can have a look. I will post my findings.

Thanks again

Alan

 

[Hurricane]

Okay I have removed the bottom bracket and it is a sealed unit. Turning the shaft by hand it feels pretty bad.

The square ended shaft measures about 140mm long and the body about 83mm. Anybody got an idea where I can source one.

Thanks

Alan

 

[Blew it]

On sealed cartridge BB's, it's usual to replace the ball races only. If you can see the brand and model number, use that to google for spares.

 

[Hurricane]

Got my bike back on the road at last. The ball races were indeed numbered. I ordered a couple and when they arrived the next day I duly went to fit them. Unfortunately they would not fit the shaft or cups.

I contacted Alien Ocean who now sell Synergie hoping to buy a new bottom bracket but the technician is on holiday till next week.

As a lot shot I thought I would try Halfords. I found a BB in there which looked very similar but was not long enough. When I got it home I removed the ball races from it and fitted them to my own shaft, put it on the bike and it pedals great with no creaking noises. Result!!

 

[John L]

Hi Alan

Good work - glad you got it sorted

John