Author Topic: Do I have a Rohloff problem?  (Read 4953 times)

one arm bandit

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Do I have a Rohloff problem?
« on: February 14, 2008, 10:16:38 AM »
I recently bought a Thorn Nomad with Rohloff and have now done about 700 miles - not much I know but enough to form an impression. I'm very happy with the bike apart from the gears.

From day 1 it's been a pig to shift from 8 to 7 with any pressure at all on the pedals. Going uphill is a pain as to ensure changing from 8 to 7 and not ending up in 14, I have to stop pedalling or reduce the weight on the pedals to almost zero, thus slowing down to a crawl. If I do manage a change it often is accompanied by a loud thud which vibrates through the frame. This noise occurs only when I manage to change from 8 to 7 when the pedals are under pressure and it appears to be getting worse - or maybe I'm learning how to force change the gears.  :)
I can see that all this may well be my error and it appears to be dependant on split second timing.

Gears 7 to 1 are very noisy with a grinding sound and seem less efficient whereas 8 to 14 are perfectly fine.

I've not yet done the first oil change.

Can I expect these issues to disappear with use?

Thanks for any advice.


peterh

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Re: Do I have a Rohloff problem?
« Reply #1 on: February 14, 2008, 10:50:51 AM »
Your hub sounds fine. The 7-8 issue is how the hub behaves I'm afraid - you get used to it eventually and let pressure off naturally. It's something to do with moving between high and low ratio and for safety it will go into top if you don't let off the pressure on the pedals. My experience is that gears will get quieter with use. It might be worth trying an oil change to see if that has a dramatic impact?
 

stutho

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Re: Do I have a Rohloff problem?
« Reply #2 on: February 14, 2008, 11:28:02 AM »
Hi one arm bandit,

Welcome to the forum,

As you are probably aware, the shift from 8 to 7, and also sometimes 7 to 8, is a special case.  It is almost akin to a chain rings shift on a derailer setup.  If pressure is not briefly removed from the peddles on an 8 to 7 change then the gearing WILL dump you into 14 gear. The gear changes on the Rohloff are VERY quick so there is a cunning way to archive this pressure reduction - only switch gears when the cranks are vertical.  This, for me at least, removes enough pressure from the peddles to accomplish a smooth gear change.  Gear changes DO improve with time, however the  8 to 7 gear change is a permanent characteristic of the Rohloff that most riders just get used to.

You can expect the noise to decrease in gears 7 to 1 with a bit more use.  The first oil change normally brings a step change in noise levels.  Having said this some hubs are simply noiser than others, my wife’s hub has maybe 1,000 miles mine has 10,000+ miles yet my wife’s hub is actually quieter than mine is!  

My advice would be to keep riding until you have a 1000 miles racked up then do an oil change.  If, after the oil change, you are still unhappy consider getting the hub overhauled by SJSC / Rohloff.  Each hub it 'tuned' to take into account manufacturing variation, getting it re-tuned can apparently make a LOT of difference (NB this is anecdotal - I don't have any direct experience).

All the best

Stutho
 


one arm bandit

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Re: Do I have a Rohloff problem?
« Reply #3 on: February 14, 2008, 11:58:25 AM »
Thanks stutho and peterh.

As I thought, its operator error  :)
and a question of timing the gear change

I'll do an oil change and see.

Super bike though, very stable.

freddered

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Re: Do I have a Rohloff problem?
« Reply #4 on: February 14, 2008, 03:04:33 PM »
1) The 'whirring' gets less over time and after an oil-change (in my opinion).  It never goes away but you will stop hearing it after a while and will start hearing your friend's rattling derailleur instead (as it clunks and crashes its way into low gears up a climb).

The noise doesn't represent as much inefficiency as you may think.  Tests have shown that a Rohloff is possibly 1% or so less efficient IN SOME GEARS than a perfectly adjusted, cleaned and lubricated derailleur (How many of those do you know?)

2) 7->8 and 8->7 requires that you back off the pressure a bit.  I always backed off by derailleur changes (I'm kind to transmissions) so it wasn't a big change for me. 

I must admit I never had a dramatic clunking like you describe though.  The worst effect I ever get it that it sticks in 14th during the shift until I back off (when it clicks into 7th or 8th).

It may be worth trying another Rohloff for comparison.  Mine seems very slick even between 7th and 8th but maybe that's just my kind-to-transmissions technique.

I'm in Andover, Hampshire if you want to use mine for a comparison.
 

one arm bandit

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Re: Do I have a Rohloff problem?
« Reply #5 on: February 14, 2008, 05:45:28 PM »

I must admit I never had a dramatic clunking like you describe though.  The worst effect I ever get it that it sticks in 14th during the shift until I back off (when it clicks into 7th or 8th).

It may be worth trying another Rohloff for comparison.  Mine seems very slick even between 7th and 8th but maybe that's just my kind-to-transmissions technique.

I'm in Andover, Hampshire if you want to use mine for a comparison.

oh yes please! I'm just down the road in Whitchurch. I've PM'd you - I hope I've done it correctly :-\

freddered

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Re: Do I have a Rohloff problem?
« Reply #6 on: February 14, 2008, 07:28:26 PM »
Inbox is empty so I guess you didn't do it correctly.

I sent you one.  Check in MY MESSAGES

I rode thru Whitchurch on Denmead 100 Audax on Saturday.  Stopped at White Hart for a beer as well.

Pity we timed it a week late
« Last Edit: February 14, 2008, 07:32:16 PM by freddered »
 

Eric

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Re: Do I have a Rohloff problem?
« Reply #7 on: February 17, 2008, 06:36:50 PM »
Just a thought, but doesn't it say in the Rohloff handbook that if there is not enough 'slack' in the gear cables, then gear changes might be difficult? I think you have to have about 2-3mm freeplay in the shifter twistgrip. Might be worth checking, as it only takes a second. ;D
 

justin

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Re: Do I have a Rohloff problem?
« Reply #8 on: February 18, 2008, 03:46:52 PM »
And on that subject, if I'm in any doubt about a shift (say from 8 to 7) I give the shifter a momentary wriggle to make sure the normal free play has returned. This seems to ensure it's properly in gear before pushing the pedals hard.

one arm bandit

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Re: Do I have a Rohloff problem?
« Reply #9 on: February 26, 2008, 05:10:05 PM »
I had  very informative meeting with freddered today. To sum up, my rohloff issue was "operator error" - there is nothing wrong. Phew!
Thank you freddered and all those who responded to my post.

steve

freddered

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Re: Do I have a Rohloff problem?
« Reply #10 on: February 26, 2008, 06:03:16 PM »
No problem, glad to be of help.

Just need to back off the pressure for a millisecond when shifting (stopping pedalling altogether would be fine but you don't need to go to those extremes)

I was impressed with the external shifter box on the Rohloff as it was actually slicker than my internally cabled shifter.