# Mystery vibration



## gumbafish (Jan 11, 2011)

So I have a problem I am having difficulty tracking down, what feels like vibration originating from my bottom bracket.

I installed a new crankset (Shimano 5750) along with a 5700 series cassette and chain so all of the drivetrain parts are new and the same group. I noticed that when I was pedalling there was some vibration I could feel in the bottom of my feet. It doesnt happen when I coast or when I pedal backwards, only when I am pedalling. 

I'm not really sure what the issue is, if I have over/undertightened parts of the crank, if maybe my BB shell needs to be faced etc... I thought at first maybe it was just all the new gear and it would take a little for the chain to break in but it has to be at least 200-300 miles now and still the same. Any suggestions or ideas about how to track it down?


----------



## Touch0Gray (May 29, 2003)

my guess is it is the new chain riding across the ring


----------



## locustfist (Feb 21, 2009)

Isolate the variables to troubleshoot.

Remove the chain (or hold it out of the way) and spin the crank to see if it is smooth and true.


----------



## gumbafish (Jan 11, 2011)

I will try taking the chain off tomorrow, but if I have the bike in the stand with the chain on and spin the cranks with my hands I can't feel it so it might be happening only when under load of me apply pressure during pedalling. While I am pedalling it feels in sync with my pedal strokes instead of a constant vibration.


----------



## Jimmie G (May 12, 2012)

Not trying to highjack your thread but I too have almost the same issue. cannondale r800 finally went in for new chain front chainrings and cassette my vibration seem to be most pronounced when on the smaller 3 gears in the rear. Im a 30 year euro car tech so I have some good skills and have taken the chain off and spun things and the only thing I have come up with is the rear cassette has some runout deflection when yo spin it backward this is driving me crazy its been to 2 shop in houston area and a month later . The first chain was a sram 951 second shimanno hg53 rear sram 970 I was told Im going to pull the cassette off next and look at stuff. I was told to ride it and seat in the chain but it shakes the chain so bad its beating on the front derailer.I bought this bike used and it was smooth as glass up until the chais got worn out no noises no chaining issues in any gear. again sorry about crashing in just thought we had same or simillar problem and could share the resources. I am a new member wish it didnt start out this way.

Jimmie

.


----------



## Touch0Gray (May 29, 2003)

pull the chain off and hang it from one end and see if it might not have a slight kink?


----------



## Jimmie G (May 12, 2012)

I thought it might be a chain issue first chain was a sram 951 changed it out for a hg53 same issue with both chains. When I say first chain Im refering to the new replacement not the OE chain sorry.

Jimmie


----------



## PJ352 (Dec 5, 2007)

gumbafish said:


> I will try taking the chain off tomorrow, but if I have the bike in the stand with the chain on and spin the cranks with my hands I can't feel it so *it might be happening only when under load of me apply pressure during pedalling. While I am pedalling it feels in sync with my pedal strokes instead of a constant vibration*.


That may be because at certain points you're applying more pressure to the pedals.

IME new Shimano drivetrains sometimes exhibit these symptoms, till well broken in - and that takes more than a couple of hundred miles. Someone once posted that it was due to the way the components were machined, but I can't confirm that. I referred to it as a rumble, but I can see how someone would call it a vibration. Mine occurred more in the lower (two smallest) cogs.

Lastly, while anything's possible, if your BB shell didn't exhibit problems with your old setup, I don't think you need to reface the shell now. Wouldn't hurt to recheck torque values on the BB cups and cassette lockring, but I'd just keep the chain lubed and ride the bike. You should notice the noise lessening first in the cogs you ride the most. 

Jimmie - if your drivetrain ran fine until you replaced the chain (and that's _all_ you've replaced), odds are that your cassette and/ or chainring(s) are worn and also need to be replaced. I'd do this sooner rather than later, otherwise you'll be prematurely wearing out that new chain.


----------



## Jimmie G (May 12, 2012)

All the chaining is new front rings and rear 970 sram cassette I have never bought a new bike but was just at bucks in roundrock thinking of buying a new bike and been looking at used on craiglist. The thing is its been smooth as glass in the past and its such a bad transition with the new stuff If it was like that new I would not buy it.I just have not found the right shop and waited too long to address this so my bad. First shop called to sell me a rear wheel said the free hub was stripped and they would leave it apart and I could come look when I got to the shop said the bike was ready now Im not sure about the wheel at all everything is tight but doesnt seem true so I need to take it apart and inspect it. I dont recall anything being loose the bike had been on my trainer through the winter and Im ready to get outside again. OK when you replace all the chaining its normal to have enough rummble to make the chain slapping on the front derailer that drives me nuts I like things quiet running smooth and true. I love the cad5 and its been a great trouble free bike but its stressed me out so much this last month it may be time for a new one. Its what I use to releive stress but its been the otherway around for a month. I see a new or used bike in my car today any body got something in the austin area?

Jimmie


----------



## PJ352 (Dec 5, 2007)

Jimmie G said:


> All the chaining is new front rings and rear 970 sram cassette I have never bought a new bike but was just at bucks in roundrock thinking of buying a new bike and been looking at used on craiglist. The thing is its been smooth as glass in the past and its such a bad transition with the new stuff If it was like that new I would not buy it.I just have not found the right shop and waited too long to address this so my bad. First shop called to sell me a rear wheel said the free hub was stripped and they would leave it apart and I could come look when I got to the shop said the bike was ready now Im not sure about the wheel at all everything is tight but doesnt seem true so I need to take it apart and inspect it. I dont recall anything being loose the bike had been on my trainer through the winter and Im ready to get outside again. *OK when you replace all the chaining its normal to have enough rummble to make the chain slapping on the front derailer that drives me nuts I like things quiet running smooth and true.* I love the cad5 and its been a great trouble free bike but its stressed me out so much this last month it may be time for a new one. Its what I use to releive stress but its been the otherway around for a month. I see a new or used bike in my car today any body got something in the austin area?
> 
> Jimmie


No, I'm not suggesting that your situation is normal. It's not. But I think the OP's situation _may_ be attributed to new parts wearing in, because I've experienced similar.

My initial response to you was based on info you provided. Now that you've added the above, I'm at a loss to suggest anything beyond visiting a reputable shop for further diagnosis.


----------



## Jimmie G (May 12, 2012)

I understand and thanks for all the help Im going to get a new bike and sort it out later.

Thanks everyone
Jimmie


----------



## gumbafish (Jan 11, 2011)

Thanks for the insight PJ352, I guess I thought a few hundred miles would be enough for them to break in. I pulled the rear wheel off and the cassette lockring wasn't totally tight so I'm about to go out for a ride now and see if that influences things. I guess it may just be the break-in period like I first suspected, just it takes a little longer than I estimated.


----------



## gofast2wheeler (Oct 13, 2011)

Had the same problem with my bike, rumble in drivetrain at 17mph all the time. Could pedal thru it or slow down. Came right thru the crank arms on downward stroke. Checked eveyting like you, redid hubs, removed crank and checked botton bracket all good. Took to LBS they found nothing. Gave up an decided it was one of those unexplainable things. Campy Chorus 9 spd. Put another 4000 miles on it well noise is gone. So, my idea is chain and front chain ring were doing it. Had 1000 miles on drivetrain since purchased, I ques it needed those extra miles to mate properly. Also, from a suggestion on this forum from someone, they said to work on my pedaling stroke. Did that as well, seems you can smooth out vibration by pedaling smoother.Try it, good luck.


----------



## Peter P. (Dec 30, 2006)

Some Shimano chains are asymmetrical, and are intended to be installed with a particular orientation. Check to see if you installed yours correctly. If you tossed the instructions, they're available on the Shimano web site.


----------



## gumbafish (Jan 11, 2011)

Yeah I have the 5701 chain which is asymetrical but it is in the correct orientation. 400+ miles and its still doing it. I noticed today that it really does it when applying force, but if I am up to speed and then pedal only very lightly (like not enough to maintain my current speed but not just coasting) it was less noticeable to not noticeable. 

I still have my previous chain, I guess I could just put that on and only pedal around the block a few times to see if that changes things without mucking up my new drivetrain by using an old chain. It is a good point about the cogs wearing in the gears I use the most, that may explain why it is worse at times than others. Next ride I will pay attention to what gear I am in, maybe the reason I am noticing differences in vibration level is just due to how much I use certain gears.


----------



## OldChipper (May 15, 2011)

I actually have what sounds like the same issue after moving a relatively new 6700 set-up to my new Ridley Noah RS frame. For a couple of weeks, I thought I just wasn't getting the FD straight and/or adjusted correctly, but I've looked closely enough at it while on and off the bike that I'm sure the chain is not rubbing the FD (but that's kind of what it sounds like though more rumbling than rubbing if that makes any sense). Like OP, it's loudest in small chain ring and biggest 3 cogs in back and louder under load than not. Maybe the old frame was somehow damping out the noise and I'm just going to have to live with it until everything wears in. :^(


----------



## PJ352 (Dec 5, 2007)

gumbafish said:


> *Yeah I have the 5701 chain which is asymetrical but it is in the correct orientation. 400+ miles and its still doing it. * I noticed today that it really does it when applying force, but if I am up to speed and then pedal only very lightly (like not enough to maintain my current speed but not just coasting) it was less noticeable to not noticeable.
> 
> I still have my previous chain, I guess I could just put that on and only pedal around the block a few times to see if that changes things without mucking up my new drivetrain by using an old chain. It is a good point about the cogs wearing in the gears I use the most, that may explain why it is worse at times than others. Next ride I will pay attention to what gear I am in, maybe the reason I am noticing differences in vibration level is just due to how much I use certain gears.


FWIW my vibration/ rumble wasn't related to chain orientation. 

As far as your comment about having 400+ miles and it still occurring, mine subsided (mainly in the most used cogs) at around the 1k mark, so ride more. You've got about 600 miles to go. :wink5:


----------



## gumbafish (Jan 11, 2011)

Hmm ok 1k, doesn't one usually change a chain around every 2k though? I guess that seems like such a long time, but at this point I think I'll take your experience and stop worrying about it and just keep riding.


----------



## Touch0Gray (May 29, 2003)

I actually alternate 2 chains and swap about every 600 miles


----------



## gumbafish (Jan 11, 2011)

Hmm ok 1k, doesn't one usually change a chain around every 2k though? I guess that seems like such a long time, but at this point I think I'll take your experience and stop worrying about it and just keep riding.


----------



## PJ352 (Dec 5, 2007)

gumbafish said:


> Hmm ok 1k, doesn't one usually change a chain around every 2k though? I guess that seems like such a long time, but at this point I think I'll take your experience and stop worrying about it and just keep riding.


I don't swap chains out, but I know others do. I keep the drivetrain clean/ lubed and periodically check the chain for elongation.

My chain doesn't come off the bike till it's time to replace it. FWIW, I get up to 4k miles on an Ultegra (10 speed) chain. As always, YMMV.


----------



## Jimmie G (May 12, 2012)

The owner of the bike shop that wanted to sell me a wheel when I didnt need it also told me he put a 970 sram cassette on and its the cheaper 950. The bike came with sh-cs7702 dura ace cassette big change in price and probably QC shimano is made in japan sram 950 ?? maybe china because it doesnt say anything on it. I bought a giant defy1 with 105 stuff on it so I could get some seat time. I went a month without regular riding and thats bad for me. I will post the results when I get the right cassette on the bike. I really like the defy its smooth and not a bad transition from the old cadd 5 R800. Thanks to everyone that helped and props to the board seems to be alot of good people on here.

Jimmie


----------



## Jimmie G (May 12, 2012)

Im posting an update on my vibration or rummble. I ordered a 7700 dura ace shimanno cassette and installed it and also took apart everything the previous shops had done they didnt clean any of the fasterners I noticed that the new sg spockets in the front were a little different in thickness and the OE spockets had some shims in between the sprocket and the crank I found 2 still on the old part. My question is do the new sg b53 need the shims behind it because as I said the mounting bosses are a little thicker. The bike is smooth and still needs a fine tweek maybe change the rear derailer 1 of the small idler spockets is worn bad. I still like the old cadd5 r800 it has served me well for my riding needs. Sorry about the rant and thanks to everyone for the advise I know you cant fix something you dont have in your hands but knowledge is power.

Jimmie


----------

