Thorn Cycles Forum
Community => Rohloff Internal Hub Gears => Topic started by: Martin Blain on March 18, 2013, 03:23:40 pm
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As most of my riding is in my own company I rarely get a chance to compare my athletic performance with other cyclists.
However this weekend I cycled a particularly hilly sportive (6200 feet of climbing in 65 miles) using a Rohloff hub and on the hills I seemed to be loosing out to the majority of other cyclists with their derailleur gears.
I'm prepared to accept that at 14 and a half stone I'm not a great climber but my experience got me wondering if the Rohloff hub was slightly contributing to my loss of pace up the hills.
I'd appreciate a little feedback on this one. Are Rohloffs less efficient on the hills or is it just me?
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Your drivetrain will be heavier than a derailleur, and then there's the possibility of a little extra drag. So they did have a slight advantage when the road pointed up.
Makes your achievement even greater.
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Very hard to tell, the last hilly audax I rode I was the only rider out of a small group of 6 who did not get off and walk one section, but all of them had compact chain rings rather than triples so It was more a case of available gear ratios rather than me being stronger than them or the Rohlhoff being superior.
I'm sure it is more likely that you are losing out to lighter riders rather than your choice of drive chain. Having shed 4 stone myself I know it make one hell of a difference to my claiming ability.
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The Rohloff is less efficient than a well set up clean running derailleur and this is especially the case when running in the lower 7 gears. I would assume for a sportive the people you would be riding against would have got their bike ready for the ride so I would say you may be loosing somewhere about 10% efficiency to them on the hills.
The Rohloff really shines when the going is not perfect and compared to a very dirty derailleur system the Rohloff will win both in terms of efficiency and reliability but this is not really going to be the case in a sportive.
Hope this makes you feel a bit better about your fitnass if not your choice of bike for the event
Andy
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I would have to say that unless you have experience riding with derailleur gearing over a similar route that you have no baseline for comparison. However, I in my experience I find that we climb in a lower gear with the Rohloff hub than we did with derailleur gearing. I also find that we accelerate slower with the Rohloff hub.
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how come the pro's don't ride rohloff ;)
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A Rohloff hubbed bike may be slightly slower going uphill than the equivalent bike with derailleurs but I doubt if it's significant, and it may just be because you have lower gears available so you change down into them.
I can't say I noticed any difference when I changed my Thorn Sherpa over from derailleur to Rohloff.
On the flat and downhill however, I think that with the Rohloff I am more likely to change up into higher gears and keep pedalling up to a faster speed than I would on the same bike with derailleurs because I hardly ever used to change up to my biggest chainring and tended to freewheel more.
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As a recent convert from Derailleur to Rohloff......
I would never go back and yes, I perceive it to be slower. Difficult to measure but not as nippy.
If I wanted to ride really fast I would stick to derailleur.
But for the riding I do and the places I go, Rohloff is perfect
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As a recent convert from Derailleur to Rohloff......
I would never go back and yes, I perceive it to be slower. Difficult to measure but not as nippy.
If I wanted to ride really fast I would stick to derailleur.
But for the riding I do and the places I go, Rohloff is perfect
Ditto. Also on a Rohloff the "Roadies" never know what gear you're in when climbing !
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ah when your on a derailleur bike at least you know your riding a bike the way it should be ridden. hate those hub gears ::)
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I have said this before ......but i like standing on the pedals, at least some of the time. I know it's not supposed to be as efficient but I like it. A rohloff is great for combining spinning with honking! You can spin for a while and then when you feel like standing on the pedals you click the shifter up a gear or two and off you go. Then when you feel like a rest you click it back into a lower gear, sit down and spin. You can't do that half as easily with derailleur gears!
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I find the rohloff slower than derailler in general, and its slightly more so on climbs. I think its all to do with the weight/inertia of the hub. It just deadens little accelerations each stroke. I've found myself struggling on hilly bits of rides, only to keep up with the group no problem (well, not as much problem..) once we got into the flat run-in towards the end.
So to martin's point, I'd say you are putting yourself at a slightly more disadvantage compared to deraillers on hilly rides. (The drag also makes the descents slower)
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However this weekend I cycled a particularly hilly sportive (6200 feet of climbing in 65 miles) using a Rohloff hub and on the hills I seemed to be loosing out to the majority of other cyclists with their derailleur gears.
I frequently ride with other friends on their derailleur bikes. I have not noticed any decline in my climbing compared to them since changing to the Rohloff - simply not my experience
Re. efficiency comparisons, there is this:
(http://www.rohloff.de/uploads/pics/image012.en.jpg)
The Rohloff is the narrow white band, hachured is the derailleur. Less efficient in the lower gears 1, 2, 3, 5 & 7. But we are talking about an efficiency loss of 1-2%. At that level you will not notice it, and it will barely show in a riding comparison. Tyre pressure and seating position will play a much greater impact. The quick shifting and even gear steps of the Rohloff are also more likely to work in your favour.
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I think we need to understand the definition of efficiency in this case.
Defining as simply a measure of work overcoming losses in the gear mechanism does not take account of work to overcome weight and rotational momentum which is significantly larger than for a derailler system. These are exaggerated during climbing.
>> The quick shifting and even gear steps of the Rohloff are also more likely to work in your favour
Disgree. The even gear steps are fairly large steps compared to many sporting derailler setups.
Quick shifting ? Nah. Negligible at best. I'd say deraillers are quicker: in my personal experience I ease off more changing on the rohloff than I do on deraillers.
>> A rohloff is great for combining spinning with honking! You can spin for a while and then when you feel like standing on the pedals you click the shifter up a gear or two and off you go.
Yes, this is possible with deraillers.....
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I think we need to understand the definition of efficiency in this case.
Defining as simply a measure of work overcoming losses in the gear mechanism does not take account of work to overcome weight and rotational momentum which is significantly larger than for a derailler system. These are exaggerated during climbing.
>> The quick shifting and even gear steps of the Rohloff are also more likely to work in your favour
Disgree. The even gear steps are fairly large steps compared to many sporting derailler setups.
Quick shifting ? Nah. Negligible at best. I'd say deraillers are quicker: in my personal experience I ease off more changing on the rohloff than I do on deraillers.
I was talking about comparisons with a similar type of bike. My Rohloff is on a Thorn Nomad so comparable to derailleur MTB tourers like Surly LHT, not a schmick Cervelo. The weight difference is well over-stated - apart from super-light racing gears, when you add in all the component changes in conversion, it is probably less than 200g difference, if that. When I built my Nomad up, it came out to exactly the same weight as the Giant Sedona MTB tourer it replaced, even with the heavier Rigida Andra 30 rims (just using a basic scales).
Gear steps - also talking about similar gearing set-ups ie. touring/MTB derailleur and wide-range cassette. The Roohloff was designed to replicate the typical MTB range - at the time of design it was comparable to the 8 spd (later 9 spd gave a slightly wider range possible using the 11t).
Shifting speed - my personal experience looking at Rohloff compared to a touring range is the Rohloff is noticeably better shifting, especially on the down-shift (except for 8-->7 of course). Derailleur gears you have a lever throw, with a lagging chain shift to the lower gear; changing up is quicker. With the Rohloff it's just a twist and the change is always instantaneous - up or down. A nice 11-25 road cassette will of course shift quicker, but Rohloff was never intended to be racing-oriented gear.
Just my experience.
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I was talking about similar bikes as well. My RST is a high-end sporty touring bike. Not really bothered about weight.
If I was to pay similar money for a deraillered machine, I would expect it to have a few kilos lighter, with better shifters.
I enjoy the rohloff greatly, its the bike I ride by far the most, but I am not saying its better in every respect to deraillers.
I was talking about comparisons with a similar type of bike. My Rohloff is on a Thorn Nomad so comparable to derailleur MTB tourers like Surly LHT, not a schmick Cervelo. The weight difference is well over-stated - apart from super-light racing gears, when you add in all the component changes in conversion, it is probably less than 200g difference, if that. When I built my Nomad up, it came out to exactly the same weight as the Giant Sedona MTB tourer it replaced, even with the heavier Rigida Andra 30 rims (just using a basic scales).
Gear steps - also talking about similar gearing set-ups ie. touring/MTB derailleur and wide-range cassette. The Roohloff was designed to replicate the typical MTB range - at the time of design it was comparable to the 8 spd (later 9 spd gave a slightly wider range possible using the 11t).
Shifting speed - my personal experience looking at Rohloff compared to a touring range is the Rohloff is noticeably better shifting, especially on the down-shift (except for 8-->7 of course). Derailleur gears you have a lever throw, with a lagging chain shift to the lower gear; changing up is quicker. With the Rohloff it's just a twist and the change is always instantaneous - up or down. A nice 11-25 road cassette will of course shift quicker, but Rohloff was never intended to be racing-oriented gear.
Just my experience.
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The weight difference is well over-stated - apart from super-light racing gears, when you add in all the component changes in conversion, it is probably less than 200g difference, if that.
Would it not matter that in a derailleur setup more of the weight is not rotational whereas for the rohloff the there is more weight rotating in the hub (all be it closer to the axel than the rim and tyre so making less difference.)
A rohloff hub weighs more than an XT or hope hub
Ewan
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Rotating weight difference (within reason) is not a major issue, really only mattering for acceleration ie. sprinting. This is not an normally issue, generally nor on climbs, unless you're Bradley Wiggins.