Check handlebars stems and seatposts many creaks originate there but sound like they come frome elsewhere. If it seems to be coming from the resr B/B get stoker to ride with hands off uphill. If creak goes away you will know where to stsrt looking. 

What type of cranks are you using?

 

We had a very similar issue that I eventually tracked down to th e interface of the Middleburn crank are and spider mounting.

You need a Shimano BB tool from Park Tools (BBT18) to fit the nut on the back.

Good Luck

Andy

Thanks for the comments.

The tandem is a Thorn with Thorn cranks on a square tapper fitting. We will check handlebars stems etc. first.

Hello Ian

Does your Thorn have S+S couplings? We had a similar creak when on tour and it turned out to be road dust in the coupling threads of the large lower joint. We cleaned and regreased the threads and were creak free! I should add that the joints were apparently tightened properly as we had checked that and initially discounted the couplings as the source of the creak!

Good luck with tracking down your creak..
Andy & Lynn
 

 

 

Sounds obvious, but have you checked the chains for wear?  A stretch indicator tool is only about £3.

Peter

One of our tandems had creaking when we put the effort in.  After much stripping, cleaning and re greasing of the drive chain I eventually traced the problem to the free hub mechanism.  The free hub in question had pawls that locked into a ratchet mechanism.  A light grease on the pawls fixed the issue.

My diagnosis process involved all of the following steps until I eventually found the issue.

• bottom brackets.  I swapped these front to back to see if it made a difference, and replaced them.  Clean and grease the threads and re tighten
• Excentric bottom bracket.  Clean, grease and re tighten.
• Clean and lightly oil the QR skewer on the back wheel
• lightly lube the spoke crossings
• remove the rear casset from the free hub, clean and regrease and tighten to the correct torque.
• clean, grease and tighten the cranks to BB
• clean, grease and tighten the chain ring bolts
• Seat posts, saddles, and handlebar clamps and bolts all tightened.

It took ages to find the issue.

Note there is conflicting advice on the internet about whether to grease the interfaces between cranks and BB, and if to grease chain ring bolts.  You have to decide which expert to believe.

Hope this helps.

I have the same problem with my current Thorn tandem, and also had the issue with my previous Thorn (without S&S couplings).  In my case I traced the problem down to the eccentric chain adjusters.  About every 1000 miles these have to come out and are given a good clean, alongside with cleaning the inside of the tube the adjusters sit in.  Because the bottom of the frame is split where the eccentrics are clamped, road grit gets in and eventually it all starts creaking.  I would like to say that typically its the front or rear crank that gets dirtiest and hence the culprit, but this is not the case!  I now bite the bullet and clean both at the same time.  If your eccentrics are old and don't fit reasonably snugly in the frame, the creaking gets worse.  Good luck with tracking the problem down and when you do eventually find the cause, please post the problem/solution - every day should be a learning day!