irratating noise when climbing out of saddle

ryan0380

I got myself my first carbon bike about 6 months ago, a Cube Agree GTC SL and I am really happy with it except for one annoying little problem. Everytime i get out of the saddle during a long or ardous hill climb there is a loud knocking noise coming from the rear wheel. I was convinced it was coming from the rear hub but a cycling companion has suggested it is coming from the rear wheel rubbing off the brake blocks as I move from side to side while standing on the pedals. One of the brake blocks has more wear than the other side. There is a bit of flex in the rims which i have checked with my hand while off the bike and this could only be magnified when all 14 and a half stone of me is out of the saddle trying to power up a hill. I have just gotten used to the creaking of the carbon but this is slowly driving me mad. I completed the 3 peaks last weekend and did as much of the climbs as i possibly could in the saddle as I couldn't continue listening to the knocking. would the rim rubbing off the brake blocks cause a knocking noise? anybody got any other suggestions as to what it might be? I got the wheel truned recently but that didn't make a difference and the skewer is as tight as it could be. please help!!!!!!!!!!!!

thanks

Beasty

If it's something to do with the brakes, it will almost certainly be happening at the same time on each wheel revolution. Have you checked this - alternatively is it at the same time on the crank revolution?

If you think it may be the brake blocks, try loosening them so there is no chance they will catch, and see if you still have the same problem. It may just be the brake alignment, which can easily be fixed.

chakattack

Rubbing brakes don't knock, they rub

Is there any sideways play in the hub?

It could be your bottom bracket/cranks/pedals or cleats creaking under force. Climbing out of the saddle generates/needs the most power.

Try to push really hard when seated to see if you can recreate the problem?

CheGuedara

Had a similar issue recently - a knocking sound evident only when working out of the saddle.

Thought it was the seatpost so removed, cleaned it and reinstalled with a healthy smearing of assembly compound: no dice.

Checked every concieveable bolt was tightened to torque: no dice.

Removed the fork, cleaned bearings and races, regreased the bearings, reassembled the front end: perfect silence! So that's where my money's at!

AstraMonti

CheGuedara wrote: »

Had a similar issue recently - a knocking sound evident only when working out of the saddle.

Thought it was the seatpost so removed, cleaned it and reinstalled with a healthy smearing of assembly compound: no dice.

Checked every concieveable bolt was tightened to torque: no dice.

Removed the fork, cleaned bearings and races, regreased the bearings, reassembled the front end: perfect silence! So that's where my money's at!

What grease are you using for the bearings? I think I need to do the same.

ryan0380

Thanks for all the replies. Nearly sure it isn't the bottom bracket cos had it checked and regreased only bout a month ago because that's what I thought it was originally. When cycling in the saddle and putting down alot of pressure there is alot of creeking but I have been told it's probably just the carbon. I have gotten used to and accepted. When out of the saddle it is a very different knocking sound. I'll try and realign rear brakes to see if it makes any difference. Knocking is def coming from the rear wheel area so could it be the forks?

Thanks again

CheGuedara

AstraMonti wrote: »

What grease are you using for the bearings? I think I need to do the same.

The Finish Line ceramic grease - can't say it's any better or worse than any other grease having used it from the off but it tends to stay where you put it and does exactly what it says on the tin.

I still wouldn't rule out the front end - I was convinced it was something on or around the seat tube which is why the seat post, clamp, FD bolts, bottle cage bolts all got first attention. Was very surprised when the problem was up front. Can feel yer pain though tracking down these noises are a PITA!

Enduroman

have you a bike computer attached? the magnet could be hittin the housing on the forks.

studiorat

Like the man says is it per wheel revolution or per crank revolution? Or just random.

Greyspoke

Enduroman wrote: »

have you a bike computer attached? the magnet could be hittin the housing on the forks.

I'd agree that you check this as there's nothing like a magnet that is too close to the sensor for causing a very annoying knocking noise. This usually does only occur when out of the saddle.

happytramp

Unfortunately, no matter how 100% certain you are that a noise is coming from a particular area the problem area can be extremely tricky to isolate. Two weeks ago I was so positive that I had a problem BB that I disassembled it, re-greased it and finally bought a new one to no avail.

So if you can verify that it's the brake block cool, perhaps you could put some coloured pigment on the blocks (like chalk) to see if it's marking the rim. If not then tighten every possible bolt (cranks, bottom bracket, seatpost, bottle cage, pedals, QR hubs, headset etc) If it's still happening remove and re-grease everything (Bottom bracket inc Axle, cranks, seatpost, pedals etc.) If none of the above helps then I really have no idea!!!

ryan0380

Not a magnet for a speedo cos I don't have one on the bike. Goin for a spin in the morning so will do some hill work, have tightened saddle, pedals, seatpost bottle cages etc. Goin to mark brake blocks with chalk l( hope it's dry tomorrow) to see if they are rubbing. If none of this works will probably start regreasing everything one by one. Did a good bit of winter riding on it but think I am goin to get myself a hack for next winter, rookie error I suppose

thanks again for all suggestions and help in trying to restore my sanity

Leroy42

Maybe its just fear!!!:D

ryan0380

Leroy42 wrote: »

Maybe its just fear!!!:D

the sound of fear leaving me!!!;)

macadam

I had this problem going up hills recently, each time I got out of the saddle and put the pressure on, first time I thought I had a broken spoke, on closer inspection the rear derailleur was over reaching and touching the spokes.

ryan0380

Finally got this sorted and yes it was the headset, bearings needed to be replaced. Thanks to everyone for their help and suggestions. My sanity has been restored for the moment, noise free cycling.