Rohloff - What's YOUR Opinion ?

[sd]

I take it back S&S is £520?? Not for me. Just thought it would save me money going to US. Doubt it.

[pyjamas]

Before I bought my Thorn RT in 2007, I read everything Andy Blance had to say about the Rohloff hub, both for and against.  What he did not mention is the drag in the hub.  Evidence for this is seen in the way the pedals turn when I walk the bike, although the handbook says they should not.  I have taken the bike back to Bridgewater to have this dealt with, to no effect.

I also tested the hub when I had the chain off, and it was very evident that there was more drag in some gears than in others.  I'd say first was the worst for drag, and 11th was best, as one would expect.  So this has proved a disappointment, especially since I've taken to riding out with a friend, who is always kidding me about haveing to pedal downhill if I want to keep up with his freewheeling!

[Andre Jute]

Seven years later you still have a bike that disappoints you? I admire your patience and tolerance, sir.

[triaesthete]

 To plagiarise BMW:  that's a characteristic not a fault Sir. 

[Andre Jute]

Or Bill Gates: "That's not an failure, that's a feature!"

[Danneaux]

Hi All!

In my opinion and experience, the one area where the Rohloff hub noticeably lags behind a freewheel or cassette-based derailleur drivetrain is in coasting performance.

This is understandable, given the extra freewheel sets in play and the multiple lip seals necessary to keep oil in and water out in severe conditions -- one of the Rohloff hubs' greatest virtues.

I just completed a double crossing (and considerably more) of both Eastern and Western Europe on AndyBG's Rohloff-equipped RavenTour with internal shifter. This has been a particularly smooth and quiet example and never even once missed a shift. However, down posted 9-10% grades with a full touring load, I struggled to make downhill speeds above 53kph even while in a full aero tuck. On similar grades with similar loads on my loaded derailleur touring bikes, I've easily managed to top 90kph.

Other people's experience may vary, but I've found similar results with the Rohloff and external shift box on my 2012 Nomad Mk2.

According to my bike computer's speedometer, drag is least when descending in direct drive Gear 11; no surprise there.

I've not found this to be a problem in practice, as with my fast-light pedaling cadence, I rarely coast and am nearly always under drive. Under drive, the Rohloff feels very, very close to my derailler-equipped bicycles in efficiency, absent the quarter-turn of the cogset needed to shift and the chain shock those bikes display with every shift. By the time the Rohloff makes it's indexed click at the hub, it is already in gear -- even if shifted while stationary.

For me, coasting descents at 53kph on a loaded touring bike are plenty fast enough on good roads, and more than needed on poor surfaces. If I truly felt the need to go faster, I could always upshift and pedal downhill. I think greater friction while coasting is a more than fair trade for the hub's other virtues, but I've found greater coasting drag is certainly evident and empirically reproducible in use. The friction is far more apparent at high speeds than at usual touring speeds, where I've found the differences to be minimal.

That said, I can't think of a better drivetrain for my tour, still to be concluded. There are no signs of wear on the Rohloff cog or Surly stainless chainring. I took great care to keep the exposed chain clean and well lubricated and there is no rust despite heavy rains. I used Purple Extreme lubricant, which in my experience lasts longer on straight chain lines than on derailleur drivetrains. The chain showed a lot of initial stretch and exhibited some snatch while stretched I initially mistook for a failing bottom bracket.  Simply taking up the excess with the eccentric put all right and everything meshes smoothly and silently.

Tip: On this particular combination of 36 X 17 gearing on this frame size/chain stay length, a doubling over of a couple links made me think they could be removed when in fact doing so would have made the chain just short of joining and without the necessary amount of needed slack. I simply rejoined the chain with a second quick-link, which will allow tool-free shortening in the future. It turned out to be such a good idea, I plan to do the same on my Nomad and would suggest a similar approach to others. When that day finally comes when you need to shorten the chain by a link pair and dial back the eccentric, the whole job can be done on the side of the road in all of five minutes.

Best,

Dan.  (...who thinks despite coasting friction, Rohloffs are anything but a drag)

[triaesthete]

 Dan, can there not be other factors at work here??  Surely, if the hub was acting as a drag brake and scrubbing off 37kph it would be generating considerable heat on any longish descent Perhaps one of you out there with a head for physics calculations could tell us how many Watts the seals are theoretically absorbing 

I've caught a few deralieurised roadies on descents round here, however this may be due to the RST on Marathon Supremes having vastly superior levels of grip (notably in the wet), braking power and bump absorption/tracking stability compared to road bikes. It also helps that the Swiss top blue and CSS rim combination doesn't start to melt and fade after a few seconds hard use like conventional rubber brake blocks on aluminium.

Curious days
Ian

[Kuba]

I've easily managed 75 km/h on downhills on my Raven Tour, in once case fairly lightly loaded. I've never ridden this fast on any other bike, and that's possibly due to the RT being super stable and reasurring on downhills. Also have done 63 km/h on a bendy road in Wales last weekend with no load at all, it could have easily been much faster but I didn't know the road and had to brake before each corner. So Dan, if you can do max 53 kp/h then there's something wrong there.

That said, the RT doesn't feal nearly as nippy as my old XTC used to on uphills and the noise does bother me. Also I'm not a great fan of the Rohloff shifter. Rohloff drivetrain certainly has its advantages but overall, with no expedition touring plans for the next couple of years, I'll be seeling on my RT/Cyclosportif combo shortly and goint back to XTC. It's the best do-it-all bike that I've ever ridden and - to me - it feels way nicer to ride than the RT. As for the drag, I'm not sure if it's there and if it is, certainly it doesn't matter overall. But the feel... not for me.

[Danneaux]

Hi Ian! Hi Kuba!

Just wondering...d'you have an idea how much distance your Rohloffs have covered?

I'm thinking a worn-in hub could be a key determinant in the apparent friction.

A friend with a Rohloff in another brand of bike also experienced slower coasting till his hub was well used. Now, it is much closer to his derailleur bikes' coasting performance.

As with my derailleur bikes, with my low-pressure, high - cadence pedaling style, I really only coast down steep hills when carrying a load. Unladen,  downhills are usually under drive as well.

What all this means is my hubs rarely coast. I'm wondering if that means seal wear has been relatively reduced as well. Yes, unlike a cassette/freewheel, an IGH can rotate at a speed different than the drive pinion, but the differential is not as great as when coasting with the pedals still.

I'm not the least dissatisfied with the performance of my own Rohloff of Andy's; quite the opposite! 'Just noticed the only really perceptible difference between it/them and my derailleur bikes was noticeable slower coasting at high speeds. At touring speeds, the difference is virtually unnoticeable. Both Rohloff bikes seem to have similar spin-down times when turning the cranks with the rear wheels elevated, and the cranks on both rotate, but not strongly.

Andy's hub was slightly quieter and smoother than mine but both functioned identically.

Of course, there's many factors that differ between these bikes and my derailleur bikes.  Some key factors could include wheel diameter,  tire section width, and tire pressure, construction, and weight. How much is due to the hub? Ah, that's the question here. Unless everything was the same *except* for the hub, there's really no way to tell. For example, my Nomad runs 26x2.0 Duremes, while Andy's RD uses Marathon Deluxe. My rando bike uses 700x32 road slicks. That's got to make a difference right there.

Best,

Dan.

[triaesthete]

 Not ceteris paribus then Dan 

I find the RST is the go to bike 99% of the time now. I find myself riding along saying, in a Mr Cholmondley Warner type of voice " Ah! Smooth! As if it were a Rolls Royce."  because it's so plush.               https://www.youtube.com/watch?v=y4CXY6TVBMc

Such a beautiful blend of qualities and abilities and simplicity. I'd say the RST mk2 was Andy's masterpiece and a classic Thorn insofar as it was the one they wanted to make, and they made it how they wanted, before being forced to follow the market up the disc brake 700c route.   Timelessly good in the way of old BMW flat twins or Andre's Citroens.

Lucky to have one, happy days
Ian

[Neil Jones]

I wholeheartedly agree on your opinion of the RST Ian, it's a superb bike. I also enjoyed the Harry Enfield clip too  .
Regards, Neil.

[Slammin Sammy]

Hilarious! 

[Andre Jute]

I've caught a few deralieurised roadies on descents round here, however this may be due to the RST on Marathon Supremes having vastly superior levels of grip (notably in the wet), braking power and bump absorption/tracking stability compared to road bikes. It also helps that the Swiss top blue and CSS rim combination doesn't start to melt and fade after a few seconds hard use like conventional rubber brake blocks on aluminium.

It does seem that both elements, large and competent tyres, and an intrinsically stable bike geometry, are hugely underrated speed breeders, especially downhill. A modern road bike is of course intrinsically unstable; that short wheelbase could be purpose-designed to make it twitchy.

[JimK]

how many Watts the seals are theoretically absorbing 

ooo I like a challenge!

So here is my approach. I use http://bikecalculator.com/ - plugging in 91 Kg total weight for bike and rider, clinchers, drops, 0 watts from the rider: a 13% downhill grade gives about 90 kph, a 5% downhill grade gives 53 kph.

Assuming ceteris paribus, it's like the Rohloff is soaking up 8% of grade. Every hour, 8% of 53 kilometers, i.e. 4.24 kilometers, of vertical energy is being dissipated. Equivalently, every second 1.18 meters of vertical energy is being dissipated. With a 91 kg weight and a planet tugging with 9.8 m/sec^2, that comes out to:

1050 watts.

burn, baby, burn!

[il padrone]

There has got to be other factors at play here Dan. Yesterday I rode a couple of fast descents with friends. In the lead group two of us were on Rohloffs, two were on derailleurs. A good range of builds and aero forms were involved, but we all coasted to a max speed of about 65-68kmh. I don't have any problems cracking 60kmh on a good descent as long as I go into a tuck.

I have yet to hit 80 on the Thorn Nomad, but that's more a case of lack of opportunity rather than friction drag. I have hit 70 on a few occasions.