Author Topic: Noisy rohloff?  (Read 4404 times)

arborstu

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Noisy rohloff?
« on: November 13, 2012, 11:29:06 pm »
Can anyone help.
Just done a bit of an overhaul on my Thorn Sterling/Rohloff and now have a noise similar to a chain rubbing on a front mech when not set up properly. It is present all the time but obviously louder when under more pressure, ie larger gears. It's one of those sounds that only appears when riding the bike so trying to locate it when the bikes on a stand doesn't work.
Oil in the hub has been changed recently and often - would the incorrect amount of oil (too little/ too much ) cause the internals to make this sound.
Rear cog has been reversed for the first time since new but the original side is very worn. Very hard work getting the cog off but this seems common.
Front chainring has been turned so is in good condition.
Brand new kmc chain.
Chain has been slackened / tightened on the EBB to try and single this option out, although the EBB casing has been adjusted a lot as the previous set up wore.
Cables are original, about 2 years old but the shifter. Taken / lessened the cable tension to no avail.
Also there feels to be quite a bit a drag and the cranks move when pushing the bike along. This was present before the noisy problem. Tried the mallet technique! with no real results though.
The hub and shifters all work fine but this noise is driving me insane and doesn't sound too healthy.

Hope someone might have some ideas or it's a day out in Bridgewater for me as I don't know any LBSs in the Frome/Bath area that might have some Rohloff knowledge.

Thanks, Stu

Danneaux

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Re: Noisy rohloff?
« Reply #1 on: November 14, 2012, 12:51:55 am »
Quote
...now have a noise similar to a chain rubbing on a front mech when not set up properly.
Hi Stu! Welcome to the Forum!

I'm surely sorry you're having to deal with such a frustrating problem; I don't think there's much more difficult than trying to track down a Phantom Noise.

Reading your description carefully, I believe I'd center my next investigation on what is happening to the chain under pedaling pressure.  By any chance -- and this is a long shot, I realize -- could the lever on the hub quick-release be on the right side? If so, there is a possibility the chain may be rubbing on it while under tension, accounting for the noise you describe. Also, if the q/r is set too tight, it can inhibit the free spinning of the Rohloff hub.

I suspicion your problem is something in actual contact. You said, "It is present all the time but obviously louder when under more pressure". It would be nice if that was the case, anyway, as it might be easier to locate and address than something internal to the hub.

You've changed the chain when you reversed the chainring and cogs, so that shouldn't be the problem. If you had put the worn chain back on with the reversed tooth faces, I might have suspected that.

Less likely, but another thing to check is the eccentric bottom bracket. It is possible one or both of the grub screws that secure the eccentric within the shell are loose, allowing the insert to rock under tension and produce noise. I realize you have checked it very carefully, but if the insert has been adjusted a number of times, it is possible the holes have run together and it is no longer being held as securely as needed under pedaling load.

I hope something in the above will help. If it doesn't, you can count on our Forum members to weigh in with useful suggestions and experience to apply. Please keep up updated as your efforts progress.

Best,

Dan.

JimK

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Re: Noisy rohloff?
« Reply #2 on: November 14, 2012, 03:13:41 am »
I put a new chain on my bike back in July or so, after the Erie Canal Ride. That ride was on fine gravel a lot and my bike got caked in the stuff. I've been using a wax chain lube and rather generously at that, so my whole drive train was thick with a wax-dust mixture. I scraped most of that gunk off my chainring and at least a good part of if off the sprocket.

When I put on the new chain, it was horribly noisy. The harder I pedaled, the noisier. I hunted around for any obvious cause. All I could come up with was that the new chain didn't really match the old chainring very wall. Maybe all that wax and dust wore the chainring quickly... I have less than 5000 miles on the bike.

I figured the chain would wear to match the chainring before long, or vice versa. And indeed it is far less noisy now, 500 miles or so later. It still gets a little noisy when I really push but it finally is getting quite subtle.

Did you flip the chainring but keep the old chain?

.... oops, sorry, I see you have a new chain. Did you just flip the chainring at the same time or a while ago? I also am using a KMC chain.
« Last Edit: November 14, 2012, 03:16:33 am by JimK »

wheezy

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Re: Noisy rohloff?
« Reply #3 on: November 14, 2012, 04:41:19 pm »
Probably won't be much help, but AVC in Bath deal with Rohloff to a limited extent. They fit them to some of their folding bikes. I find Cadence to be the most helpful bike shop in Bath, so bear them in mind as well.

I have a new chain, and chainring running on a part worn sprocket which is making a bit of a racket at the moment. Fortunately for me, the racket from my front disc is drowning most of it out. Not sure I'll be able to stand it for 500 miles, though...

geocycle

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Re: Noisy rohloff?
« Reply #4 on: November 14, 2012, 05:33:34 pm »
??? Check the horizontal alignment of the EBB -have you skewed the chain line? Also make sure the rear skewer is not too tight?
 

Cambirder

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Re: Noisy rohloff?
« Reply #5 on: November 14, 2012, 09:02:09 pm »
Sound a bit like the problem I had with a new KMC chain

http://www.thorncycles.co.uk/forums/index.php?topic=4194.0

JimK

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Re: Noisy rohloff?
« Reply #6 on: November 14, 2012, 10:20:13 pm »
FWIW I am using a KMC Z610HX DropBuster BMX Bicycle Chain.

I was out riding today and paid special attention to that nasty noise. It is really 99% gone now. If I really push I can hear a subtle extra sound but even climbing hills mostly it is quiet now. I do tend to be on the high cadence / low torque end of the spectrum, at least when I am not all the way out in the low cadence / low torque corner! The noise really does sound like a chain rubbing against a front derailleur cage!

As that noise was dissipating, was I wearing the chain to match the chainring, or the chainring to match the chain? I have a bad suspicion it was the more expensive chainring that took the brunt of it!

Andre Jute

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QR
« Reply #7 on: November 15, 2012, 12:58:16 am »
....was I wearing the chain to match the chainring, or the chainring to match the chain? I have a bad suspicion it was the more expensive chainring that took the brunt of it!

A real-life example of Gremlin's Law.

John A Gremlin was an early Irish cyclist and gear-cutter. His motto was, "The chainmaker done it."

Andre Jute

PS On the OP's problem, I vote for a QR done up too tight. I was surprised to see that the maximum torque rating of the QR axle is only 7Nm/62in. lbs (as compared to 35Nm/310in. lbs. for the nutted axle). My QR was replaced by the maker of my bike with a nutted version (not the big axle nut -- the Rohloff QR and nutted versions are not interchangeable -- but just a small security measure) and there was a definite graunching noise when the first time I took the wheel out I did it up to tight because I thought just a light twist of the wrench would do it. 7Nm is a torque wrench job, every time, and a QR needs careful adjustment not to exceed that. See p14 of the manual. More torque ratings on p124.

I bought a small torque wrench (the BBB kit which comes with most of the appropriate bits and is good value -- the wrench is the same as in more expensive kits) especially for use with my Rohloff gearbox because none of my other torque wrenches (mainly for working on Bentleys from the railway shed days of engineering) went as low as most of the Rohloff requirements. I highly recommend owning a small torque wrench if you have a Rohloff, because the lowest of the Rohloff maxima can be exceeded just spinning a wrench shaft between your fingertips.

PPS Er, for those new to the forum, of course I invented John A Gremlin. He wasn't really a gremlin, he was a leprechaun. See also The Great Scientific Leprechaun Hunt, http://coolmainpress.com/ajwriting/archives/2490

gearoidmuar

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Re: Noisy rohloff?
« Reply #8 on: November 17, 2012, 05:16:23 pm »
My guess is worn chainring. I've had that problem. Fixed by new chainring.

berchman

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Re: QR
« Reply #9 on: November 25, 2012, 01:26:39 pm »
I bought a small torque wrench (the BBB kit which comes with most of the appropriate bits and is good value -- the wrench is the same as in more expensive kits) especially for use with my Rohloff gearbox because none of my other torque wrenches (mainly for working on Bentleys from the railway shed days of engineering) went as low as most of the Rohloff requirements. I highly recommend owning a small torque wrench if you have a Rohloff, because the lowest of the Rohloff maxima can be exceeded just spinning a wrench shaft between your fingertips.

This is probably a stupid question, but it is coming from one who lacks mechanical talents. I cannot see how a torque wrench can be used on the lever of a quick release, on a nut, yes, but on a lever?

tressell69

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Re: Noisy rohloff?
« Reply #10 on: December 02, 2012, 05:31:54 pm »
I had the same problem, the noise was driving me nuts.
Changed front chainring, bought new chain and noise sounded like a buzzing sound when pedalling with an intermittent grumbling feeling through the pedals.
Fitted a new rear cog and voila, silence is golden.
I maybe could have flipped the cog, but just fitted a new one to be sure.
The noise happened again just recently but not as bad and this time I flipped the cog and silence once again.
New and old just dont match , think Anna Nicole Smith and that old billionaire she wed!

Hope this helps
Raymy

Andre Jute

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Re: QR
« Reply #11 on: December 02, 2012, 11:49:42 pm »
This is probably a stupid question, but it is coming from one who lacks mechanical talents. I cannot see how a torque wrench can be used on the lever of a quick release, on a nut, yes, but on a lever?

The quick releases on the hubs of my bikes have been replaced with nutted shafts as a security measure. The nuts are operated by socketed bits that fit the torque wrench. There is no lever on these shafts, like the one on a quick release. I can do this because I haver run belted tyres and don't expect to have flats, and indeed haven't had a flat in ten years.

My point was that it is very easy to exceed the very low clamping force recommended for quick releases either with the quick release lever, or in my version by whatever shaft you're turning the nut with, whether torque wrench or tommy bar.

As for your remark about what one can possibly fit into a torque wrench, try ShelBroCo Tools. See for instance the Tork-Grip at http://sheldonbrown.com/tork-grip.html With one of those you'll never need to worry about over-torque again.

Andre Jute