PoeCo

Hello all....

We've had a noise on our tandem for the last several rides and cannot seem to figure out what it is/where it's coming from. We've replaced the BB, chain, chainrings, cassette, pedals, and tightened (or checked) everything else we can think of like the crank arms, brakes, etc, and still it persists. It seems as though it is something rotational because if we stop pedaling for a couple of seconds and then go again, it disappears for a short time, but then returns shortly thereafter (maybe 30 seconds to a minute or so later) and seems to happen in rhythm to our pedaling. It doesn't seem to be coming from a saddle or seatpost either. The sound itself is kind of a creaking sound, but it's fairly loud, methodical, and SUPER annoying (particularly to me). But, more importantly, I don't want a problem to get worse if there's something wrong (which I can only assume there is because it didn't make this noise prior).

Anyone have any thoughts on something to check/possible source of the noise?

Thanks in advance!

tandem rider

Sounds can come from cleats/pedals, seat posts/saddles or wheels. If possible, take turns standing while pedaling to eliminate seat posts/saddles. To eliminate cleats/pedals, one rider at a time takes their feet off of the pedals while the other rider continues to pedal. Another noise possibility is the wheels. Is it possible to borrow wheels to ride a short distance while listening for the sound?

pipeliner

Did you replace both bottom brackets? I had a similar noise and found it to be in the BB. Headsets can do this to you as well.

Paul J

That can come from several possibilities. You will want to start with one of these at a time and work your way through the list. I'd start with the easiest and work toward the hardest. Check lubrication on your chains. Next, check the tightness of your seat posts and seats to seat post. Next, mark where the top of your seat post comes out of the frame and then pull your seat posts. If your frame and seat posts are steel and/or aluminum apply some lithium grease and reinstall. Next, if that doesn't work, take your pedals off and apply Lithium grease to the threads and reinstall. The more involves would be checking make sure your eccentric is lubricated and tightened properly. Service your bottom brackets. We have a DT/Swiss rear hub and it sometimes will squeak when it needs service. Servicing these hubs is very important as a poorly services hub can damage the pawl mechanism and require replacement, at it's worst the wheel will not want to freewheel when coasting. Those are some thoughts, if you have a belt drive you will have some areas to investigate with that. Looking at your other picture I can't tell some of these things, so a closer picture might give us some other ideas to pursue. Good luck.

Bellman

Several years ago we had onset of a repetitive sound on the tandem, a kind of low frequency grinding/popping, only while pedaling. We went through every part we could think of and did all the diagnostics folks have mentioned here. Long story short: final resolution - it was my right knee! Bet you didn't want to hear that!

reburns

Long shot, but the last time I had a noise fitting those symptoms that was difficult to find, it turned out to be at the rear dropouts. Some interface between the dropout and the hub/axle/skewer? In any event, it disappeared after cleaning and lightly lubing the faces of the dropouts.

Leisesturm

Seatpost clamp in our case. Can also be a crack in something. It will eventually fail, and then the mystery will be solved. Do not spend anymore money until it does :-)

gcb

Had an intermittent creak that would often increase with increased pedal pressure. Took apart multiple things with no luck before finally noticing a small crack in the rear rim at a spoke hole. Replaced the wheel and that took care of the creak!

PoeCo

HA! No, that isn't what one would hope for!!

PoeCo

Thank you all so very much for your thoughts!! They are all greatly appreciated (and humorous, in some cases).

We will keep up the investigation... we're pretty good about lubing and checking things each ride, but it's always possible that we've missed something along the way. We hadn't thought of the wheels (though we did have a broken spoke not too long ago, so maybe those need to be checked again). I would think if it was a wheel issue, even if we weren't pedaling it would still make the noise, but I think we just need to eliminate everything as a possibility, so certainly worth checking those as well.

Again, thanks to all for your thoughts. Always greatly appreciated!!

Paul J

PoeCo, I couldn't tell if your tandem is a Com Motion. If it is, it may have the DT rear hub. It is a very good hub but must be maintained. The issue with them is it can make the noise during pedaling and not when coasting as it can be assigned to the ratching mechanism in the free hub. Good luck.

PoeCo

The tandem is not a CoMotion (it's a Rodriguez), but checking the hub certainly wouldn't hurt anything!
Thank you for your thoughts.

Alcanbrad

Also check the interface points between the cable housings and frame. I once had a similar annoying creak and it turned out to be the short shift cable housing between the chain stay and rear derailleur at the chainstay end. Cleaning and a little grease on the outside of the barrel solved it.

DCwom

We had a mystery noise that would come & go only when pedaling and on the bike, never on a stand. It turned out being a loose BB, not the BB itself, but the retention cup/nut/thing. It really sounded like it was the stoker BB and all of our investigation was focused there, but it was actually the captain's BB.

sloppy12

try leaving the stoker at home. I did that and it fixed the issue. it came back as soon as I got home though.

PoeCo

Ha! I don't think he would like that. We are in less-conventional captain/stoker positions as he is the stoker and I am the captain. It actually works well for us though because he's a lot more mellow with the happenings of shifting/pedaling than I am.

PoeCo

This is my suspicion. I think it has something to do with one of the BBs... so, either the one we replaced is just a bad one, or it's the captain's BB that has gone bad... or, perhaps something is just loose in that area, as you've suggested.

It's absolutely frigid here this week and we're expecting snow over the weekend, so probably not going to get to test any of the theories/suggestions here for several days, unfortunately.

base2 

On the bottom bracket track: The eccentric may not be bound in as tight as it should be. I too have some Rodriguezes in the stable & unlike the older wedge style eccentrics of yore, the Bushnell eccentrics they manufacture in the machineshop down stairs sometimes need a second torque applied to the fixing bolt after making adjustments. Usually not much, but it is an aluminum fitting pressing into a much harder steel shell. It's not unheard of for the aluminum to giveway & form fit to any inconsistancies.

On another track: I once had a rythmic ticking while pedaling at a certin speed. It was the plastic cap on my shoelace slapping down on the top of my shoe with every rotation. Man did I feel like a dolt for getting myself worked up over nuthin' 😖

On another bike of mine the presta valve nut loosens for some reason and at one speed it makes a ticking noise as the balance between gravity & centripidal force oscillates with every rotation. Removing the valve nut or retightening it against the rim solves it.

Good luck. I hope your issue is simple fix.

sloppy12

My stokers are 8 and 6. they didn't like it when I left them home either.

PoeCo

Thank you! We hadn't thought about it being specific to the Bushnell eccentric, so that is another great suggestion. Also interesting about the presta valve nut. Sometimes the smallest things can become such a nuisance.

I have been there with something slapping on my shoe and not realizing that it was the noise source, so I feel your pain!

I hope it's a simple/quick fix too, as we're running out of things to try at this point. Thanks again!!

Carbonfiberboy 

If it's in rhythm with pedaling, it's probably not a wheel. A free quickie is to pull both seatposts (marking them first), grease the seat tube and post and reinsert, clean up. This kind of thing is very often a seatpost.

sapporoguy

We had an infuriating noise that sounds a lot like this, which seemed to be coming from the back. I'd replaced stoker BB so sure wasn't that and had spun the pilot's cranks without chain and it spun freely with no play. I did just about everything possible--pedals, skewers, whatnot.
Then I took off the front crank and spun the righthand bb bearing with a finger--too tight! And there signs it was so tight the shaft was sometimes slipping inside the bearing race under certain conditions. replaced front BB and noise was gone.

xlbs

Stems?

No one has mentioned stems, yet they are often the source for annoying noises coincident with pedalling since they "rock" with your body. Simple test too...remove bolts, grease, and reset.

PoeCo

Interesting. I think the BBs/eccentric are where we will start our next round of investigation. I am fairly convinced that it is something in that vicinity as so many other bits have been checked, changed, lubed, etc.

PoeCo

This is definitely not the stems, but those can be annoying and infuriating noises as well. Anything that creaks or squeaks constantly can get irritating very quickly!