That study is not high end, it has the worst of engineering reductionism/determinism (text like "For some reason that is not apparent," is a sign that their underlying hypothesis of what the heck is happening has gaps) and no accommodation for uncertainty in measurement (likelihood of greater variation between trials than between treatments)

The Paragon tube splitters are offered in SS or Ti. As the SS ones cant be brazed with brass rod (per Paragon) how do I join these to my steel frame? Silver solder? TIG? Chewing gum?

I suspect the needle and ball bearing lavished Rohloff , and a plain bushing internal
like a Sturmey are different , but the trace differences in efficiency
is a merit less comparison in the real world .

It's transportation after all , if it gets you there a half second slower
due to an .05% increase in some bearing surface resistance parameters,
then so be it, relatively , worse if you don't catch all the green lights
on your route.

Disclaimer: I'm a derailer(RIP Sheldon) guy. This due to never riding an IGH, though I'd love to ride a "nice" one and perhaps I'd become an IGH guy, though I don't see a need.


I've never had a problem with the derailer system. Once set up, It does it's job and is easily maintained by myself. It's a very simple mechanism that sheds outside contaminants pretty easily since it's all exposed. In the wet they work flawlessly. Those crazy MTB cats put derailers through all kinds on hell and they stand up to it. Go home, hose them off and re-lube and you're ready for the next time. A steel cassette lasts plenty long, and steel rings are available and last a very long time as well. Derailers don't have to be expensive to work. Even the cheapy cheap ones do their job. If gumming up of shifting is a concern, then friction shifters that work regardless of muck and grime can be had for wicked cheap.

I'm also curious about the affect of riding a longtail bike(Xtracycle, Big Dummy, Yuba, Madsen, Kona Ute, etc.) on derailer efficiency because of the lesser angle of engagement from chain to cog/chainring due to further distance between them. (I ride an xtracycle-equipped MTB for daily rider, as well as a Cross Check and the Xtra seems less affected by cross gearing.)

When I was looking for a winter bike I wanted a chaincase - seemed really cool, would definitely keep all that road grit off the chain, and I can definitely see stuff lasting longer with one, you know? :-)

The problem, sadly (in the US at least), is finding one. They seemed really cool, but the only bikes that seemed to come with them were either the more expensive Breezer models (which I could not find in any store anywhere in the Minneapolis/Minnesota area and I wasn't going to buy a bike sight unseen), or really cheap "cruiser" style bikes meant for only the most casual riding. :-(

Always seemed like it would be really cool to have one though...

Unless I'm misunderstanding what you're saying, if you're spending most of your time in 6th gear you could fix at least part of your problem by putting a larger chainring on the back. If I remember right, 4th gear is the direct drive gear, if you put a bigger cog on you could spend most of your time in the 4th gear and still have plenty of range on both sides?

5th is Direct Drive, and I totally agree that a slightly smaller cog in back would allow me to stay in 5th rather than 6th.
This is one of the inherent limitations at the moment with the belt drive system, as the only rear cog that I can get for the Alfine is a 24T. I do have options up front (I am currently using a 50T and have a 55T in my spare parts bin) but I actually like my current gear range (29" low gear, 90-something high gear) for the area I live in (Rocky Mountains).

I'll stick with it until I feel like the 11sp is dialed in (or just bite the bullet and get a Rolhoff).

Despite the relatively new application the belt drive represents (to the bicycle world anyway), I have truly enjoyed the system on my bike and feel the combination of a belt drive and an IGH is a fantastic match. I know (as with any new application) the system will go through its own evolution, and I look forward to what the future brings.

Chucky - Based on your comment below, I guess I am a fool :D So be it.

I was looking forward to this new 11 speed... as a bike builder and rider of 20 inch wheels it offers pretty much everything a touring cyclist or folder owner could ever want and the more even steps solve the issues that the 8 speed has.

It just has to prove itself as being bombproof and my experience with other Shimano IGH drives has not encouraged me... I see too many of them in my shop that need overhauling and replacing the internals is a $140.00 touch.

Am going to go and build a new wheel set for my folding touring bike and will be using an 8 speed cassette with the existing triple... will give me all the range I need and because being able to service the bike in the road the derailleur system makes great sense as none of the parts are hard to source. I could run a double but the triple gives me the cleanest and straightest chain lines.

Know from experience riding this bike over many thousands and thousands of miles that my 7-8 hour days in the saddle would not be as pleasant with an 8 speed IGH as the small gear steps I get with a close range block really help with stamina over 110-160km a day.

I usually tour at much higher speeds and rpm than most... my friends consider 20kmh a nice pace and I am often dialing it up to the high 20's and and can maintain this all day.

With that... I am off to ride my folder as it is actually too nice to be sitting and discussing cycling when you can be cycling.

I don't know Paragon's specs, but stainless is usually brazed with a high-silver filler, often with nickel, e.g. 50N -- 50% Ag/2% Ni, or BAg-7, 56% Ag.

Stainless is harder to braze than other steel alloys and has to be silver brazed with rod that is silver with added copper and tin with no cadmium.

It is one of the most difficult materials to work with as it requires careful preparation and exact heat control to prevent anealing and brittleness which will reduce the corrosion resistance and may cause failures.

The optimal method to work stainless is to TIG weld it as the gas shield prevents oxidization and the heat control can be very precise.

Yes I already said that. Add it to the 3-5% increased efficiency from setting it up properly for the final result....assuming you're capable of setting it up properly.

Right...so where is the study you published on drivetrain efficiency? [Redacted immature insult, I don't expect to have to do this again. Capeche? Walter, Moderator]
The results of the study I posted are not unique. It just happened to be the most easily accessible link.

You've done a poor job at extrapolating those results to the real world.

I set the range (30" to 92"), then I pick the primary gear ratio (38x18). The 5-6 step is unavoidable in any reasonable use case....

22T rear cog is available http://www.vaust.com/catalog/gates-c...b73vmisrpu9as6
I am currently using a 50T/22T in my commuter.

Good to know. I'm certain that more options will become available with time.
I accepted the inherent limitations that come with any new application in order to try it for myself. The only thing keeping me from slapping the 22 on there now is the knowledge that I'll need to do battle with the frigging lockring ;)

What's insulting is HardyWeinberg's attitude towards the hard work of those who have actually performed experiments and published their results. Not that I expect you to care because, after all, the authors of the study aren't part of the herd your advertisers are paying you to keep blithely ready to consume.

:lol: Because you say so? The proof of the pudding is in the eating. The real world speaks for itself.

No, "HardyWeinberg" is correct. You may not understand his arguments against the quality of the study, but they do nail some of the more general problems with this study. Fx. the lowest efficiency measured on the triple crank is in the middle ring with the straightest chainline. That result is hard to explain, so they don't, and that is a major problem, because this error propagates through the entire study. Taken at face value, this study shows that deviating chainlines (cross chaining) plays little if any role in efficiency (probably true) but that the straightest chainline actually lowers the efficiency (probably untrue). In any case, this clearly systematic error makes the entire study very problematic to use.

Besides that there are numerous small errors and inaccuracies like "Ultegra Mtn. Grupo" (Table 2. p.11): There has never been a Shimano Ultegra MTB group, and "grupo" is neither English (group) nor Italian (gruppo).

As a more general note, I am personally always vary of studies funded by commercial companies like the above study (Browning Research made bicycle gears). Especially if the one of the authors, like in this case, previously have written very favorably about the funding company's products.
Such studies tend to be both biased and made with crass commercial agendas.

Take the "research studies" showing that the breakfast meal is the most important meal of the day so one should always eat a hearty breakfast. Take other studies that clearly contradicts this. Now guess which studies are funded by major breakfast cereal companies and which are independently funded.

--
Regards

Um, no. More likely it is due to a lack of logic and reasoning skills. I'm just pointing it out.

For a couple years, I did a 38 mi r/t commute on a Nexus 8 hubbed bike with all the commuter geek stuff, like VO fenders, rear rack, dynamo hub, etc. I liked I a lot. Then I built up a derailleur equipped "fast" commuter which is stripped down to just a handlebar bag. Last year, it saw the bulk of commuting duty--bigger gear range more appropriate to my hilly then flat commute, closer spaced gears.

While riding that bike, I got a different frame for the IGH ubercommuter, and set it up with a tensioner and two chainrings up front. Sold it before putting any miles on it to finance frame building class.

Now building my next Ultimate Commuter, and it will be a derailleur bike.

If I was doing a city commute, I'd probably opt for IGH. There will be an IGH bike in my stable at most times--currently working on an S2C r20 project; I'm eyeballing some pretty sick closeout prices on Gary Fisher Simple City bikes and last year's color Belleville--but these are mainly for-fun or around town bikes.

For my longish, rural commute, I'm going with derailleurs.

As a mechanic who has worked on and ridden both systems, one is better than the other only in context of intended use, or more accurately, personal preference for intended use; they both have their advantages and disadvantages.

All-state 11 brazing rod with the right flux for stainless should do it. The local welding shop here said a pound of the nickel rod would cost me 30$. ESAB is the company that makes all-state rods and they make a flux for stainless too... call a local welding shop and talk to them. I've yet to try this myself so I am not vouching for it per se, but there are other options besides expensive silver rod.

Looking at the study in more detail than I should have bothered to, the only place I can find any claim for a 5% improvement in efficiency for a larger cog was where it showed a 5% difference between the least efficient gear selection in the 27 speed derailleur system vs. the most efficient. In other words, the worst case. The least efficient used the small cog (12T) and the most efficient used a 20T.

The second and third most efficient gear choices were with a 16T cog. This on a cluster that had cogs up to 34T. So the concept of "bigger is better" isn't really demonstrated by that study. Also worth mentioning is that even though 20T cog was part of the most efficient combination, when used with the middle chain ring it was the 3rd least efficient.

In fact as it turns out, an even bigger impact on efficiency than using the small cog was using the middle chainring for some reason they couldn't explain.

It's also worth noting that every gear option tested on the derailleur system except one was more efficient that any of the gears on a Rohloff.

Both the derailleur systems and the IGHs had a sort of roller coaster pattern when came to efficiency as you moved up the gear range with the general trend being downward. So by choosing a larger cog, you may actually be spending more time in a less efficient gear. But there are a lot of variables.

Even if it were true that bigger is better you could certainly set up a derailler system that has you spending more time on the larger cogs. With many IGHs you're limited as to how big you can go when it comes to cog size.

I'd say that your claim that IGHs are more efficient when set up properly is pretty shaky. By knowing which gears are the most efficient in your hub you could certainly select a cog that places you in the more efficient gears more often (and it's not always a bigger cog), but you can do the same with a derailleur system.

:popcorn:

:)

I don't want to come off as anti-IGH. I've spent a few hours this weekend building one into a wheel and I'm pretty excited to get everything else in place so that I can try it out.

It's just that I've never seen anyone claim that an IGH is more efficient before and Chucky has a less than endearing way of presenting his arguments. ;)

Oh, for sure.
This is the first I've also heard of the claim that IGH is more efficient. The banter is fun to watch. Chucky has "set himself up" by virtue of the immobile stance and hyperbole that is infused in his posts. He clearly has his point of view and is willing to battle to the death to persuade everyone that he is right. I have no desire to become tangled in that mess of thorns. *sniffs the air* I smell a troll.

I use IGH's on my bikes and like them, after having ridden for 35 years on derailleur drive trains, and see the benefits of both. I really don't care to discuss the finer points of the two with scientific reductionism, so have sort of sat back and watched the fray unfold.

I've been reading about your IGH project and look forward to seeing your experiences with it.


EDIT:
I do feel the context for scientific studies has its place, namely top end racing, where minute differences in efficiency can mean the difference between winning and 4th place. However, such discussions in a commuting forum seem absurd to me. This is in no way meant to offend those who've felt compelled to engage Chucky, but I think the conversation has digressed into finer points that really have little influence on the commuting experience. There are so many factors outside of drive train efficiency (personal fitness, mood on any given day, wind, bike setup, terrain, etc) that essentially relegate the minute differences between IGH and derailleur systems to "background noise" in this context.

Life is about compromises... went with an IGH and a derailleur this evening.

http://ravingbikefiend.com/bikepics/...dualdrive5.JPG
SA AG dual drive conversion