bkrownd

I don't care about time, I care about effort and physical pain. Sometimes I swear my hubs are really pepper mills. Every little bit of resistance is a curse on my existance. I'd like to give the Rohloff a try on my hills, and see if the hype is true.

jur

The point of the exercise was that with the same effort level, you had to maintain it just a bit longer, you'd hardly notice.

But perhaps you hubs are particularly inefficient? Then those calcs don't count.

OneTinSloth

considering that you just pulled those efficiency numbers out of your ass, your argument isn't a very good one. re-post when you have some real numbers to plug into your equation.

the efficiency argument is what most people use as a reason to keep internal gear hubs out of competetive cycling, where efficiency is key. 6 minutes is more than enough time to clean and lube a chain to keep it running efficiently.

OneTinSloth

i dunno, there are some hills around here that if i had to maintain my hill climbing effort for six minutes longer than it takes to climb them, i think i'd notice. six minutes is a loooooong time on a hill.

bkrownd

It's not the "same effort" if more effort is wasted through friction. Whether gearing choice would offset that extra effort enough for me to ignore it...I dunno.

Rohloff claims 96%+, but I've seen other references to something more like 90% average. Need to study more...

jur

They weren't just out of thin air, check bjkeen's post. Assumptions based on fact like I showed are common place in the real world where you very seldom have exact figures to work with.

And there was never an argument that they be used for racing. And good luck cleaning and lubing your chain properly in less than 6 minutes. The simple "wipe down the outside and dribble on some lube, wipe excess" does not do a good job regardless of what you may think.

Looks like you weren't reading the preceding posts properly. re-post when you have carefully read up.

jur

Oh bother... that was 6 minutes in the entire 30km ride, of which 5km was a hill.

OneTinSloth

if you regularly (once every week or two) lube your chain and wipe down the excess, it won't get all gritty and nasty, and lubing it will take much less than 6 minutes, as the lubing/wiping off the excess will actually clean the grit out of the inside of the chain links. even dripping lube on each of the rollers of the chain individually takes less than a minute, and that's the only way i ever do it, does a fantastic job of keeping the chain clean and lubricated.

if you're the sort who just rides their bike into the ground, rarely lubes the chain, and when you do, you don't wipe it off after then yes, you'll have to remove the chain, soak it in de-greaser, and then re-install it and lube it, which will indeed take much longer than six minutes.

as far as keeping internal hubs out of racing, that's the only argument i've ever heard where efficiency was a legitimate factor, and it was brought up in an earlier post.

it's still six minutes more, and i would still notice it, to say that i wouldn't notice is to deny the passage of time. you would notice when you looked at the clock on the wall and realised it was six more minutes had passed than when you rode your derailleur-equipped bike.

for the record, i'm not anti-internal gear hub, i like them very much, and i think my next bike will use the nexus 8 speed. i just think you're full of crap.

grolby

Who does? IF there is a racing future for internal gear hubs, it is in MTB circles, where the benefits of internal hubs for DH and possibly even for XC are clear. For DH, the "disadvantages" of weight and inefficiency are no object to their other advantages. In XC, it remains to be seen whether internal gear hubs will come to be seen as a competitive option.

For the record, there are those that see internal gear hubs as being not at all out of place on a fast, recreational (but not racing) bicycle, such as Sheldon Brown, who I believe has a road bike built around the Nexus 8, and likes it just fine. Sounds like a good idea to me, but this is rejected by most recreational road riders. Fine. If the criterion for "belongs on a fast bike" is "would be suitable for competive racing," then no one would argue that an internal gear hub is going to be the right tool. I happen to think that this is a foolish criterion, but that's my opinion.

But all of this is completely irrelevant to the value of internal gearing as a functional component of a commuter or utility bicycle, which has always been the most "serious" kind of bicycle and cycling there is. Here there is simply no contest, in my opinion - the durability, reliability and simplicity (in operation and adjustment) of internal gearing win over derailer gears, big time, unless you're climbing Mt. Everest in order to get to work. And yet, even among serious, year-round commuting cyclists, I hear the same racing arguments against internal gearing, repeatedly. What foolishness! There are reasons for many North American commuters to prefer derailer gearing to internal gear hubs (price of the new hubs, for example), but weight? Inefficiency? Red herrings. Internal gearing gets a much worse rap than singlespeed or fixed-gear for commuting (which is in fact lauded by many), which is odd given that internal gears offer much of the same benefits of low maintenance and reliability while meeting the wants and needs of far more cyclists than singlespeed or fixed-gear drivetrains ever could. "Internal gears: all of the convenience of a derailer, without the inconvenience of a derailer." Modern internal gear hubs allow the commuter and utility cyclist to have their cake and eat it too. Why all the hate?

grolby

I might notice. Would I care? Nope. I can always leave six minutes earlier.

jur

Usually the line taken by those who just ran out of common sense things to say.

I'm not arguing anyway, merely presenting a calculated line of reasoning and rubbing you nose in previous posts which you keep ignoring.

bkrownd

play nice, peeps

motorhommmer

I think you have it worng. There seems to be a trend for MTB to ride single gear now.

bkrownd

I'm not sure the "durability" of the newer internal gear hubs is well known. I've talked to just one person who had a lot of experience with them, and he wasn't pleased with durability or serviceability. (not sure which model) It would blow chunks if you dropped $$$ on a hub and wheel that can't be serviced, and it degraded or broke in a couple years.

grolby

This is a very limited trend, and for good reason: even more so than on the road, riding with a single gear ratio off-road is FAR more challenging than it is to ride with multiple gears. A singlespeed MTB simply cannot tackle the kind of terrain that a multigeared MTB is capable of. I'm not really sure what this has to do with the growing interest in internally geared drivetrains on MTBs; internally geared bikes may or may not have a race future. Short of a creation of a new class, SS mountain bikes certainly do not. For recreational off-roading, SS is certainly more popular than internal gearing, at the moment, but this has nothing to do with any supposed greater suitability of SS to the wants or needs of most riders. If most MTBers ended up wanting only one gear, that would change, but this is not the case right now.

bkrownd, that's a good point, but I don't really know what to make of it. Certainly the reliability and durability of the SRAM and Shimano 7-speed hubs is pretty well established. Things are less clear in the case of the Nexus-8, but I've heard conflicting reports. Interestingly enough, most of those already inclined to like them seem to downplay problems, while those who were already inclined to dislike them emphasize any problems. It's difficult to get a good reading on the truth. Given Shimano's reputation for quality control, I'm going to bet that the Nexus-8 will have a record similar to that of the older 7-speed hub. Some will break, most will give thousands of miles of reliable service. I haven't heard anything different from most owners of Shimano and SRAM 7-speed hubs, and I find it hard to believe that Shimano could somehow go from producing a 7-speed hub that is almost a model of reliability to an 8-speed that won't go more than 2,000 miles without self-destructing.

motorhommmer

I think you ignore the all importants fact that if you do have a problem with this hub here in Dublin, for example you are on your own. I talked to two LBS's who I use and they will not fix them. They will not touch them for a repair, but will send them back to Shimano somewhere, which means you have no bike until it is fixed.
This is the real issue for me, I am ok fixing things and am pretty handy, but there are a lot of people who do not want to be faced with this problem.

HillRider

This will be a problem almost anywhere. Internal gear hubs are complex, non-intuitive and require special tools and parts that aren't available to the home mechanic and most bike shops won't take the time or have the training to work on them.

Another factor that seems to have been overlooked in the "efficiency" comparison between internal hubs and derailleur gearing is that internal hubs still have a chain, a rear cog and a chainring in the drive train. So the efficiency numbers for the hub have to be multiplied by the efficiency of a chain drive and the product is lower than either by itself.

amaferanga

This I think is taken into account when stating efficiency figures for gear hubs. It would be a little daft if it wasn't! Since with a hub gear you always have perfect chainline then losses in efficiency from the cog/chainring - chain interface are less.

Its funny how some people are obsessed with the apparent inefficiency of gear hubs. I wonder if the same people obsess about optimum tyre pressures and optimising their riding position so that they as a rider are in the most efficient position. Efficiency isn't the most important thing for most of us. I enjoy cycling so if it takes a little more effort to get from A to B but I still enjoy it and my bike is nice to ride then I enjoy the journey.

And its worth pointing out again that all the comparisons between derailleur and hub gear systems have been in with perfectly maintained systems. I wonder how the figures would compare with both systems maintained to some avarage level that represents the cycling population. I'm sure the hub gear figures would change little, not so sure about the derailleur system though.

Would a very very light headwind (1 or 2 km/h) represent a bigger additional effort than that of a hub gear over an IDEAL (not real world) derailleur system?

HillRider

I expect they don't. The hub manufacturers want to put their product in the best possible light so they are going to publish numbers that sound the highest. Rohloff's number of "96%" has to be for the hub alone.

As to obsessing over efficiency, yeah, I guess we do.

Rincewind8

IIRC there were some efficiency number in "Bicycling Science" and I think I remember seeing up to 98% for derailleur systems and up to 90% for internal gear hubs. I am pretty sure about the number for the derailleur systems, but not so much about the one for the internal gear hubs. Also I don't know which internal gear hubs were tested (if I remember right they made some good efficiency improvements in recent years). Maybe someone that has the latest version (third) of "Bicycling Science" handy could look it up.

Edit: the efficience numbers mentioned were for the COMPLETE drivetrain including chain/chainring/... for both systems.

amaferanga

I'm wondering where that figure of 96%+ actually comes from. All I can see on the Rohloff website is a statement that claims the hub rivals a well maintained derailleur system in good conditions, but in severe conditions the Rohloff loses less in terms of efficiency compared to the derailleur system.

I doubt that Rohloff are stupid enough to compare just their hub to a complete derailleur system, though the perfect chainline means that there will be minimal losses from the chain/sprocket/chainring.

bjkeen

The information I cited includes the crank and chain drive as a whole. Otherwise it'd be a fairly ridiculous comparison. Basically the measurement is when 100W is applied to the crank, seeing how much power is applied by the wheel to a dyno.

bjkeen

Someone has.

bjkeen

Apropos hills, when I was tooling around on my Nexus 8 Karate Monkey this weekend (in Pennsylvania, so there were some hills) I didn't notice any especial drag from the hub. It was especially convienient for climbing out of the saddle because you can downshift instantly and extremely smoothly just by timing the twist to when your feet are at 12 and 6 (ie not right in the middle of the power stroke)

jur

The more you talk the more I want one.