Infuriating rattling noise on bumpy roads

[Mongol_Waaijer]

After a 1.5 year wait to succesfully remove a severed carbon seatpost from the frame I have recently recomissioned by "old" Trek Madone 5.2 (despite a healthy aversion to all things Trek).

I have Dura Ace levers, shifters and chainset, but run a SRAM 10 speed chain and SRAM cassette on it, as I prefer SRAM chains.

Since its rebirth there is an annoying rattling noise emerging from the rear of the bike whenever i ride over pave, bumpy roads etc that I cannot identify. If I lift the rear wheel a few cm off the ground and "bounce" it I hear the noise also.

My only theory is that perhaps I cut the last chain too long and it is rattling - maybe against the sides of the front derailleur?

Any ideas what else it might be?

 

[FKLance]

Could be the inner tube valve rattling against the rim. Try putting tape around it? Maybe the cassette or something else is loose. Or the chain is way too long.

 

[dsut4392]

After a 1.5 year wait to succesfully remove a severed carbon seatpost from the frame I have recently recomissioned by "old" Trek Madone 5.2 (despite a healthy aversion to all things Trek).

I have Dura Ace levers, shifters and chainset, but run a SRAM 10 speed chain and SRAM cassette on it, as I prefer SRAM chains.

Since its rebirth there is an annoying rattling noise emerging from the rear of the bike whenever i ride over pave, bumpy roads etc that I cannot identify. If I lift the rear wheel a few cm off the ground and "bounce" it I hear the noise also.

My only theory is that perhaps I cut the last chain too long and it is rattling - maybe against the sides of the front derailleur?

Any ideas what else it might be?

The list of possibilities is long...these are just some that I have witnessed:

Could be a long chain but more likely hitting the chainstay than sides of the front derailleur.
Bit of cra* in the seat tube that's rattling around on top of the BB? (How did you remove the old seatpost? could something have broken off it?)
Or how about your rear wheel, is there play in the bearings? (either worn/poor tolerance sealed bearings, or cup/cone bearings that need to be regreased & tightened)
Play in the freehub (not properly attached to hub, or bearings worn out)?
Cassette locknut properly tight (the separate sections of the cassette can rattle against each other)?
Quick release done up properly? (woman on our group ride a couple of weeks ago had a nasty rattle from her front wheel when hitting bumps, stopped to investigate and it was only the lawyer tabs holding the wheel in as the QR was completely open - glad she was hanging on at the back of the bunch as it could have been messy at 50kmh with traffic around)
Tube of glue rattling round in your patch kit box?
Broken seat stay/chain stay?

 

[STODRR]

The list of possibilities is long...these are just some that I have witnessed:

Could be a long chain but more likely hitting the chainstay than sides of the front derailleur.

Cassette locknut properly tight (the separate sections of the cassette can rattle against each other)?

I recently jsut had both of those. I had to take it to the shop to figure out the cassette rattle thing never had that before. it was a sram cassette also. He replaced the locking ring

 

[Mongol_Waaijer]

I recently jsut had both of those. I had to take it to the shop to figure out the cassette rattle thing never had that before. it was a sram cassette also. He replaced the locking ring

I guess it could be the cassette. Certainly seems most likely. I tend to not make it really tight so I can get it off again...i switch between race and training wheels frequently and only have one cassette....how tight should it be? so tight that's its murder to get it off? if so I'll get one for each wheel set!

Wheel is a brand new Mavic Aksium, so it shouldn't be anything wheel related. wheels are definitely properly attached....

chain is the same length as always - cut the new one always same number of links as old one...

 

[Andy.G]

Look at the front ... noises have a way of referring ... like ventriloquists throwing their voice !! Correct headset tension ?

 

[dsut4392]

I guess it could be the cassette. Certainly seems most likely. I tend to not make it really tight so I can get it off again...i switch between race and training wheels frequently and only have one cassette....how tight should it be? so tight that's its murder to get it off? if so I'll get one for each wheel set!

Wheel is a brand new Mavic Aksium, so it shouldn't be anything wheel related. wheels are definitely properly attached....

chain is the same length as always - cut the new one always same number of links as old one...

If it's loose enough to rattle you should be able to feel the play just wobbling it with your fingers (whether it's wheel, cassette or freehub related).

Just because the wheels are new doesn't mean that's not the source. Check the wheel for free side-side play at the rims. IIRC Aksiums have an adjustment nut on the non-drive side that sets bearing preload, so it's an easy fix (but the same feature also makes the problem more likely to happen IMO).

Regarding the cassette, the torque is specified on the lock-nut. From memory, a Shimano cassette specifies about 34Nm which is otherwise known as "proper tight!" if you're not using a torque wrench. If you don't torque them down properly they can have a habit of coming loose, and this may be worse if you swap it over between wheels frequently (I think the little washer between the lock-ring and cassette can wear). If you can get it off without using a chain whip it's certainly too loose. Dpending on your race wheels you may want to be careful just how tight you torque it. The aksiums are fine to torque down because there is a steel washer between the cassette and the freehub, but on some other wheelsets that don't require the spacer (e.g. my wife's Easton EA90SLX) the inboard side of the freehub isn't machined flat and can bite into the soft alloy cog carriers of the cassette. I had to swap the cassettes between our bikes because the alloy carrier deformed unevenly against the freehub on her wheels and wouldn't sit straight, causing a very noisy and poor shifting system. She got my new cassette, and her old one luckily worked fine on my Dura Ace 7850CL wheel.

I never had to have the freehub on my Aksiums off so I'm not sure how likely that is to be the source. Mine had a little play from the start but never caused a rattle.

 

[richwagmn]

I recently jsut had both of those. I had to take it to the shop to figure out the cassette rattle thing never had that before. it was a sram cassette also. He replaced the locking ring

I had this same thing happen on a shimano cassette. Owner error though. I simply had not tightened the lock ring enough when I switched cassettes.

 

[brianf7]

Check cassett for play in the sprockets and ckeck the skewer leaver for wear.

 

[galaxy1]

this probably isn't your issue, but I had a weird and very unnerving creaking noise (which could be described as rattling) for months that i simply could not track down. I suspected the handlebars because it usually seemed to be from the front end, and sometimes seemed to come when I moved hand position.

in the end I'm pretty sure it was the saddle rail making the noise - I moved the saddle forward slightly (from a very set back position) and it stopped. I'm not certain because it took a few rides to notice that it had stopped!

 

[Fourier]

Look at the front ... noises have a way of referring ... like ventriloquists throwing their voice !! Correct headset tension ?

I was thinking the same thing. I use to hear a rattling noise when I hit bumps or pavé and I thought it came from the back of the bike. In the end it had something to do with the spacers and the headset.

 

[buckwheat]

how tight should it be? so tight that's its murder to get it off? if so I'll get one for each wheel set!

Don't mean to be a wise guy but get a wrench with a longer handle.

 

[purpletezza]

solution

Does it only rattle when free-wheeling? Does it stop when pedalling? If so check your cassette is not loose on the freewheel assembly. Even if you have tightened the casstte lock nut right up the casstte may be loose. Very common when running shimano cassettes on Mavic wheels as the wheel's freewheel body is wider than the cassette so the cassette is loose and rattles, easily fixed by adding a thin spacer/washer onto the freewheel housing before sliding on the cassette.

 

[Rekibdama]

Hi Mongol. I know it was a very long time ago (2010)... but did you ever get to the bottom of that rattling problem?

"Since its rebirth there is an annoying rattling noise emerging from the rear of the bike whenever i ride over pave, bumpy roads etc that I cannot identify. If I lift the rear wheel a few cm off the ground and "bounce" it I hear the noise also."

I've got exactly the same problem, and IMHO it's coming from the Ultegra chain ring, which seems to amplify a small amount of rattle as the chain leaves the big ring on bumpy roads. Like you (back in 2010) I get the same sound if I let the rear wheel drop a couple of centimeters. Can you remember what solution you found?