Rohloff Drag

[Templogin]

Hi Folks

I had the back wheel jacked up on the eXp last night, spinning the pedals to check that gear selection was OK as I had the EX box off earlier.  Everything was fine, except that the pedals continued to spin when I let go of them.  When I grabbed hold of the pedals the back wheel, spinning in 14th gear slowed down much quicker than I imagined it would.  This 7 year old-ish Rohloff hub has done less than 300 miles by all accounts.

Is this normal behaviour until the hub has a few more miles under its belt?

Thanks

Andy

[wheezy]

I think this may be normal, full stop.

Mine's done over 6000 miles and it sounds no different to yours. The drag is less significant in practice than we might think, but it's there just the same.

[brummie]

You may also find noise / drag varies depending which gear you may be in.

[Andre Jute]

It's said to be the drag of the seals. It's not much, imperceptible on the road.  I think it was Chalo Colina who described the Rohloff's total additional drag, including this "seal drag", as an excess over the theoretically most efficient derailleur setup as less than a foot of inclination in a mile which nobody would notice without expensive instrumentation.

[Andybg]

I have always found the noise and drag of the freewheel in the Rohlhoff in the high gears, especially 14, to be excessive. Options are either shifting back down the box on long declines when you are freewheeling or on short desents just pedal.

Rohloffs have lots of advantages over derailleur systems but freewheeling in high gears is not one of them

Andy

[Templogin]

Thank you for the help and advice.  The one foot per mile adds to the seven feet per mile of having the dynamo on.  I was thinking that I was struggling up hills because I'm a fat old bloke!

The Rohloff hub is a wonderous thing, and I now ride derailleur geared bikes only if I have to.

[Andre Jute]

Well, according to the German handbook, a few years old, that came with my bike, that "seal drag" that spins the pedals when you push the bike is supposed to go away after a few thousand kilometers. My bike has only done between 7 and 8000 kilometers, so I wouldn't know; the pedals turn when the bike is pushed. I've never heard of someone whose pedals stopped turning putting a number on it. Be interesting to hear from someone without the Magic Rohloff Cranks That Rotate By Themselves.

[JimK]

I'm at about 14,000 km and my cranks still turn when I push the bike along.

[rualexander]

Yes the pedal turning friction is very slight. On my Sherpa when I first put the Rohloff on, I was using the Rohloff chain tensioner and the cranks didn't turn when pushing the bike. When I changed to running without the tensioner the cranks started to rotate when pushing the bike.

[geocycle]

Yes, 30,000 km and they still turn.

[wheezy]

Any advance on 30,000 Km (20,000 miles)?

Be nice to think in X00,000 miles the bloody thing might have finally run-in.

[Andre Jute]

Looks like the true elite, the A-list of Rohloff owners whose cranks don't turn of their own volition -- isn't us. Oh woe.

Well, never mind, snobbery was only a passing temptation. We're above all that. Sniff.

***

Seriously, the question arises, Which seals are causing this drag? Surely it can't be the paper seals; they'd be frayed by now.

[Danneaux]

Seriously, the question arises, Which seals are causing this drag? Surely it can't be the paper seals; they'd be frayed by now.

Andre, the Rohloff Manual, pg. 6 of the General Use section, here: http://www.rohloff.de/uploads/media/1_General_use_En_2014_02_web.pdf says...

Should the bike be pushed, it is possible that the cranks could also start to turn.This occurs dueto the hub seal automatically activating the sprocket. Bad seals and a very light running bottom bracket make it easier for the cranks to turn. A drop of (Art. #8402) through the holes in the sprocket onto the hub seal will reduce this activating effect.

Given this, it would seem the seal behind the sprocket is causing much of the drag responsible for turning the pedals when the bike is pushed.

Best,

Dan.

[Andre Jute]

Will you be putting a drop of the cleaning oil on the filter, Dan? At first impression I'm inclined not to, and for this reason: even that light cleaning oil will just collect more dirt on the filter, and in the end make the condition worse, and you'll be engaged upon an endless cycle of putting drops of oil through vertical sprocket holes. I don't think the pedals turning is enough of a nuisance to turn it into an everlasting worse nuisance.

Or, more succinctly, It's against my ethos of a minimum maintenance bike, thank you very much.

[Danneaux]

Will you be putting a drop of the cleaning oil on the filter, Dan?

Not likely, Andre. In the desert environment where I take the Nomad, the talc-fine alkali dust would soon turn to a grinding compound if I added oil.

It seems to me as if -- apart from the friction it induces -- seal drag is a good thing in that it means things are still er, "sealed".

For what it is worth, I find I have *more* pedal-turning since switching to the Phil Wood external BB, as it has little friction of its own and so poorly resists any seal friction against the drive sprocket.

All the best,

Dan. (...who is *still* waiting for Hebie to produce a 36T Chainglider; hope springs eternal)