Thorn Raven bottom bracket creaking

[taylor529]

The bottom bracket on my Thorn Raven has suddenly started creaking.  I have tightened both crankshaft bolts to ensure that that is not the source of the noise.  I have tightened the eccentric securing bolt,  my first suspects as these have come loose on me in the past.  I have checked that allthe spider nut and bolt sets securing the chainring are tight and still I get a loud creak every time that I push down the left foot on the pedal.  I even tried repositioning the eccentric and fixing it at a slightly different chain tension.  What could be causing the creak.  I have barely done ten thousand kilometres on this outfit?

[blair]

Have you seen the topic "RST - Plauged with noise" in the Rohloff Internal Hub Gears forum?
http://www.thorncycles.co.uk/forums/index.php?topic=1384.0

(ps - anyone know to do a cross-post in a more civilised fashion?)

[geocycle]

taylor529 you have my sympathy!  It's the most annoying of bike ailments.  In my case the holes made by the retaining bolts on the EBB had coalesced.  My problem was solved by completely removing and repositioning the EBB and applying lots of grease to the BB shell and the cranks.  Could you have some corrosion perhaps?

[taylor529]

The creaking has been banished.  Thanks for the help.  I borrowed a crank puller and removed the left crank.  I slackened the EBB set screws, slackened and removed the chain.  The set screws were then completely removed and the EBB eccentric shell just dropped out complete with bottom bracket.  I found numerous pits in the aluminium shell from the various times at which I had adjusted the chain.  I also found two long scores from the time that the EBB had come loose 6 months ago while riding.  All these indentations had raised rims of metal which I filed flush with the surface and polished with emery paper.  The surfaces and all the threads were smeared with Loctite nickel anti-seizure grease and everything reassembled.  No Creak!

[geocycle]

Good news!  Glad you've got rid of the creak.  My EBB also has some deep score marks from when I tried (unsuccesfully) to remove the BB itself.  I even bought a replacement EBB but have not needed to fit it as the noise was banished.

[taylor529]

Aftermath - 50kms into my first long ride, 30kms or so of gravel road included I had stopped and bent down to check the setscrews with my bare hand.  To my horror the screws were not even finger tight.  I promptly brought out my 15mm spanner and retightened them.  I shall keep a close watch on them in future.

[justin]

I know this has been all aired before but I have a BB creak and it's driving me mad. I've read all the forums.

It's a Raven Enduro. I have Octalink crank set. So far:

I've run the EBB shell greased, I've run it ungreased.
I've removed and replaced the EBB and the cranks about 3 times now, torqued and re-torqued, now above spec in desperation.
I've run the BB threads greased, ungreased and now with locktite. (I haven't yet tried plumbers PTFE tape!)
I've run the octalink splines greased, and now ungreased.
I've checked out the EBB. Only 2 clean holes in it where the pinch bolts go now. 2 good deep holes as they've been (over) torqued several times up to about ~15nM now. I can't believe this bit could seat any better, but that doesn't absolve it.
I've replaced and re-tightened chainring bolts.

What's creaking? I can't really tell. It only starts 15 minutes into every ride and it's impossible to re-create inless I'm riding (and my ears aren't by the BB!). It can do it with pressure on either pedal, but loudest on max torque. It's a kind of creak/squeak like new leather (no I don't have a Brookes saddle!). It's not the seatpost either. The character of the noise changes every time I re-assemble the BB area. I'm getting fed up with this. Is it the EBB, is it Octalink? (I know these have a reputation), is it chainring bolts?

[stutho]

Is it the EBB, is it Octalink? (I know these have a reputation), is it chainring bolts?

Yes it is probably one of these it could also be the BB cup rubbing on the BB shell.  I know it can be infuriating finding clicks and squeaks.  The best advice I can give is useLOTS of copper grease on everything you can get to.  If that doen’t works then you need to eliminate some of the variables. If possible try switching the cranks and / or bottom bracket with one from another bike.  Obviously this means removing the BB from the EBB - something everyone fears the first time. 

My guess is - because you have tried most things already - that it is the cup to shell interface on the BB. 

Best of luck

Stutho

[justin]

Well thanks Stutho.

I started out with everything liberally coated in copper grease. It ws quiet for a couple of weeks before it started creaking. Then I read in some forums that grease on octalink splines can be a bad idea. I de-greased everything and re assembled with just a little light gear oil, but running the octalink splines dry. That didn't help.

I take your point about the threads into the EBB. First time that was copper greased, second time it wasn't. When you say "the BB cup rubbing on the BB shell",  I take it the "cup" is the ring with the RH thread, and you are proposing this may be loose? (50nM on mine)- Or do you actually mean the "lip" of the BB which slightly overhangs the Thorn BB frame "shell" by about 1mm at on one side? (I don't think that bit touches). I read that some people think the BB ring (cup?) should be locktited (& grease on the LH thread at the other end). - That did nothing either.

I have an old bike with a square taper set-up. I'm beginning to think I'll need to raid the BB and cranks off that to try out an alternative to octalink. I still can't be sure it isn't the EBB within the frame though.

I'm also considering scary lash-ups which perhaps require trying to tighten the octalink splines with a interposer "substance". (I'm thinking alu foil or some other horrendous idea).

[stutho]

the BB cup rubbing on the BB shell

Sorry bad terminology on my part - what I meant was the cup (yes the ring) rubbing on the cartridge (the main part of the bb).  It is a relatively common course of noise from the BB area.  One end of the cartridge sits inside the cup any movement between the two will result in a click every revolution.

One other quick trick to try.  (It’s an easy one so do it before you strip out the BB.)  Remove both cranks and take out the EBB.  Insert the EBB back into the bike the wrong way round (i.e the left on the right) reattach the cranks and tighten the chain as normal.  Make sure you are tightening up the EBB with the thick side towards the bottom (as per the thorn instructions).  By doing all of the above, you should be using a fresh area for the EBB for bolts.  Obviously, you don't want to leave the EBB & BB in backwards for a Long period of time but a 2 week trial should be fine.  If you find that the click is gone the it is time to suspect the EBB frame interface.

Stutho

PS Can't see any reason not to grease the Octolink splines.

[justin]

Hi Stutho.

I like the reversing the EBB trick. One to try if I get time at the weekend. I guess long term like this risks unthreading the BB.

[stutho]

yes - but it is a remote risk when your BB is set to 50NM.  Short term you should be fine.

[justin]

BB update!

I turned the BB round on Saturday as you suggested Stutho. I didn't get entirely new EBB holes though because I had bought this frame secondhand. Saying that the holes I used on the other side were clean and initially fairly shallow, so they looked OK. I re-greased the EBB outer also.

First 10 miles (Saturday ride) were quiet.

Sunday, me and friends took on a pretty strenuous ~40 miles of the South Downs Way from West Meon to Steyning. (Beautiful day!). For 10 miles BB was totally quiet, then for 20 miles it creaked, and went quiet at the end. (I think because I was running out of torque!)

I've done another 30 miles so far this week, and with a recovered set of legs, it's now creaking away again about 50% of the time.

So I'm beginning to live with this, but still a little irritated by it. I think swapping the BB and cranks for my old square taper one will come next on the list when I find some time.

Best regards.

[justin]

OK.

Final embarassing enlightenment today. It's the pedals! 

After dis-assembling BB for a third time this weekend. Creak Creak. I climbed off to open a gate and .. creak. (But I wasn't moving...Whoa that's a first!).

Having done all these exercises countless times, pushed, pulled, jumped on the pedals, lubricated and bent everything in sight. I'd never heard it while stationary before. - This was surely a result! It turns out to be my Shimano M424 pedals.

This was funny because I'd already discounted the pedals, having ridden not clipped in, ridden with one leg, pulled and lubed them. These pedals have a black nylon platform surrounding a standard double sided SPD cleat. When I ride hard, my aged and flexible SPD's push slightly on the nylon platform, causing it's nylon bush where it locates on the SPD insert to creak against dry axle. Lubing the SPD cleat itself, or the SPD bearing was having no effect on this joint. While riding not clipped in,  I guess I was pushing the nylon outer, so they still creaked.

Climbing off a bit wonky at the gate I was pushing hard on the nylon SPD pedal outer (which I don't normally do), nailed it.

A dab of bike lube right then in the CORRECT place fixed it instantly!

So I deeply apologise for any inference that this was caused by either Octalink or EBB!

Thanks Stutho.

Closed.. Silence is golden.

[freddered]

My SPD shoes creak in a similar way sometimes.  Some shoes are worse than others and rotating the pedal normally fixes it.  When I rode LEJoG I used more suncream on my spd plate than on my body as it stopped it for a while.