Author Topic: Rohloff spoke lacing uncertainty  (Read 3918 times)

willywombat

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Re: Rohloff spoke lacing uncertainty
« Reply #60 on: January 31, 2020, 07:29:00 PM »
Sorry Pavel ..you have made a mistake

 ( Macspud made a small error involving one word "wrong" ) but the 2nd photo clearly shows the leading spokes to have heads on the inside of the flange.

Just to clarify :  the leading spoke is the spoke which exits the hub in the direction of wheel travel .

I also noticed you seem to imply earlier that the leading spokes pull the most ..this is not my understanding . As always ..could be wrong .

Perhaps all the confusion isn't aided by people using different/incorrect terminology.
« Last Edit: February 01, 2020, 09:34:23 AM by Danneaux »

Pavel

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Re: Rohloff spoke lacing uncertainty
« Reply #61 on: January 31, 2020, 09:43:29 PM »
Sorry Pavel ..you have made a mistake

 ( Macspud made a small error involving one word "wrong" ) but the 2nd photo clearly shows the leading spokes to have heads on the inside of the flange.

Just to clarify :  the leading spoke is the spoke which exits the hub in the direction of wheel travel .

I also noticed you seem to imply earlier that the leading spokes pull the most ..this is not my understanding . As always ..could be wrong .

Perhaps all the confusion isn't aided by people using different/incorrect terminology.

A leading spoke, as you've defined it would have more tension on it, while a training spoke would have less. Leading spokes are what get pulled in order to move the wheel. 

as the view is reversed, the leading spoke, which is the spoke which gets tensioned, or pulled along for the direction of travel, have their heads out, as per Rohloff's dictates.  in photo number two, the chain would pull the wheel in a clockwise direction.  Looking at the left side of the photo, that would mean that the leading spoke, which is the driving spoke, would pull the wheel from bottom to top.

it in other words leading spokes trail  the direction of moment, because spokes don't push - they pull.  The trailing spoke at that instance has less load on it, and it keeps the wheel round and centered.

Perhaps that is where the discrepancy of understanding lies?  Which goes back to your initial assertion that all is ill defined, and we understand the terminology different one from the other.  But even if we label the leading/trailing definition in the opposite way, the photos show a consistency, with no contradiction.  Looking at the left and the right, they are mirror images.  :)
« Last Edit: February 01, 2020, 09:34:30 AM by Danneaux »

Pavel

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Re: Rohloff spoke lacing uncertainty
« Reply #62 on: January 31, 2020, 10:03:16 PM »
In Jobst Brandt's book "the bicycle wheel, 3rd edition" on page 24 through 27 he illustrates how torque acts in the opposite direction of travel of the driving force, which of course makes sense when you consider how torque (which is a resultant force) tightens the threads on a sprocket which goes on with regularly cut threads, tightened in a clockwise direction.

He does not use the terms leading and trailing but rather pulling and pushing.  It's kind of long enough to be a pain to type out, so I will extract just what I think is relevant.

" the pulling spokes stretch and become longer, and the pushing spokes compress and become shorter.  The rim bulges inward at the pulling spoke and outward at the pushing spokes while the average tension, and therefore average compression, does not change"

I'm not sure if that gives us any progress towards our understanding of things, or makes it cloudier, but I thought I'd put that out here.

My brain hurts now.  :D
« Last Edit: February 01, 2020, 09:34:38 AM by Danneaux »

martinf

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Re: Rohloff spoke lacing uncertainty
« Reply #63 on: January 31, 2020, 11:06:17 PM »
The reason I'm not giving advice as to what to do and why you should do it is simply a) I don't remember everything we decided and why over the decades b) as others have said before, learning to build a wheel using components that cost over £1000 is just not a great idea.

I've probably built or rebuilt about 100 wheels since I started doing it. Even the mediocre wheels I built when I started were better than some of the factory wheels that have been through my hands.

I was aware that there were some special recommendations for the Rohloff hub (specific length of the bend at the spoke head, angle drilled rims). Taking account of the price of the Rohloff, and rather than research all the requirements and maybe risk missing something important, I decided it would be better to get SJS/Thorn to do the job. I wasn't disappointed by the quality of the SJS/Thorn wheelbuilding.
« Last Edit: February 01, 2020, 09:34:45 AM by Danneaux »

willywombat

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Re: Rohloff spoke lacing uncertainty
« Reply #64 on: January 31, 2020, 11:21:51 PM »
And the saga continues ..yes my brain hurts too but my understanding is from the famous Sheldon Brown's wheelbuilding  article , and he knew jobst Brandt well .

I have to admit there does seem some inconsistency regarding use of the terms (as you will read) but I still think most people see it how Sheldon does or did.

Here's a quote from his article where he attempts to simplify things ( unlike Brandt )

"Definitions:

This article uses 3 non-standard terms, because standard terms have not been agreed upon in the industry:

"Key" spoke. This is the first spoke to be installed in building the wheel. Its position determines the position of all the other spokes with respect to the valve hole.

"Trailing" spokes. In a rear wheel, the trailing spokes are those which become tighter when the rider applies pressure to the pedals. They are called "trailing" because they point backward from the direction the hub is turned in. In the illustrations for this article, the trailing spokes are shown in red and yellow.

"Leading" spokes. These are the spokes that exit the hub in the direction of rotation. They are illustrated in two shades of blue.

The "trailing" spokes pull harder under drive torque to make the rim turn, and the "leading" spokes contribute by pulling less hard under driving torque. Each group of spokes contributes equally in its own way to turning the rim to keep up with the hub.

Trailing Spokes

Trailing Spokes
Some writers have referred to the trailing spokes as "driving" or "pulling" spokes, and have referred to the leading spokes as "tension" or "static" spokes. These terms may be confusing, because all of the spokes contribute to driving, they are all under tension and they all pull. Depending on how you look at it, either all of them or none of them are "static". (Thanks to John Forester for suggesting "leading" and "trailing".)"

Roger Musson in his professional guide to wheelbuilding manual  seems to agree , I've attached p26 ..have a read.

Have a google for images using these terms ..I haven't looked far but didn't see any confirming your viewpoint , but several
 
confirming the opposite , apparently more common interpretation.

I'm not interested in "winning"  any arguments ..I just like things to be clear ..or at least to use the most commonly terms when discussing technical subjects ..otherwise we don't stand a chance.




 
« Last Edit: February 01, 2020, 09:34:53 AM by Danneaux »

mickeg

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Re: Rohloff spoke lacing uncertainty
« Reply #65 on: February 01, 2020, 01:39:59 AM »
...
He does not use the terms leading and trailing but rather pulling and pushing.  It's kind of long enough to be a pain to type out, so I will extract just what I think is relevant.

" the pulling spokes stretch and become longer, and the pushing spokes compress and become shorter.  The rim bulges inward at the pulling spoke and outward at the pushing spokes while the ...

I am not following this thread closely so perhaps I took something out of context here, but the word pushing jumped out at me.

There are no pushing spokes, if spokes were so elastic that a spoke could "push", it would effectively have negative tension, the spoke nipple would push against the rim tape and against an inflated tube, both of which are not substantial enough to counter much of a push and the spoke would bend to the side, like pushing on a spaghetti noodle.

Spokes are supposed to be tight enough (in tension) that even under hard pedaling (or with a disc brake, hard braking) with a heavy load on the wheel, all spokes will be under tension, the tension level would vary from one spoke to the next.

I mentioned above that I get confused by the terms leading or trailing so I prefer pulling and something other than pulling, but I would not use pushing as a viable term here.
« Last Edit: February 01, 2020, 09:35:03 AM by Danneaux »

Andre Jute

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Re: Rohloff spoke lacing uncertainty
« Reply #66 on: February 01, 2020, 08:30:16 AM »
Uh-huh. I also knew Jobst Brandt, though not as well or as long as Sheldon did. Jobst was a great engineer, both at Porsche and in the bicycle industry, and engineering friends at other leading houses he worked at admired him too.

But there is no hiding that Jobst was as ornery as any Prussian can possibly be, and he was a mean-minded infighter when he had made a mistake, so that getting him to make a correction was a major adventure, only for those with strong stomachs. People tended not to confront him with his errors for fear of his dismissive manner. (I know that for a fact from the private encouragements I received -- from people who'd backed off even when they were right -- when I did confront him about a mathematical error in his book on the wheel. Note the qualification: I know mathematics but I don't claim to know better than Jobst how a wheel works.)

Worse still, Jobst, an American born and bred, thought in German, and German, as we have already seen in the kerfuffle about the Rohloff manual (which I, who have spent most of my life in literature, consider perfectly well-translated), is a language which doesn't fit well into the exuberance of it's wayward stepchild, English.

The upshot is that when Jobst says "pulling and pushing" I don't assume he made an engineering mistake -- he knows a spoke doesn't push -- but a mental translation too close to the German in his mind, and I turn automatically to Sheldon's terminology for a clearer understanding, which, in Sheldon's hands, is usually self-evident, blindingly obvious, even inevitable.

Leading spokes leave the hub in the direction of travel, trailing spokes leave the hub in the backwards direction.

The words leading and trailing tell you everything you need to know. The words are self-explanatory, self-evident.

***
Pavel, if you have to read Jobst's book to understand how a wheel works, you're lost before you start building it. That book is one of the great engineering minds of the last century showing off. (Check out Jobst's brakes for the Porsche Grand Prix car, still the basis for the brakes on almost every high-performance car.) I have no doubt that Jobst is right, and the other writers on the subject before Jobst were at best 75% right, but Jobst's book is also the best explanation I know of why you should let someone experienced build a wheel on an expensive hub or, if you insist on doing it yourself, at least start with cheap components.

On the other hand, using The Bicycle Wheel as a mental trampoline can be most illuminating and conducive to restful sleep!
« Last Edit: February 01, 2020, 09:35:13 AM by Danneaux »

willywombat

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Re: Rohloff spoke lacing uncertainty
« Reply #67 on: February 01, 2020, 10:02:34 AM »
Whatever the outcome of the thread it's proving entertaining and educating , if only in the sense that so  much confusion exists !

 Give the example of Roger Musson's ( wheelpro )  much lauded book on the subject ...from which I attached a page above. He makes it clear re " Trailing and Leading " orientation  ( like Sheldon + Jute  ;) )
but also uses the terms " Pushing and Pulling "  !

I see the thread titled has been changed by Dan ... Can it be changed back if Rohloff acknowledge their mistake ? ( sorry.."alleged" mistakes in the handbook ? )

Anyone using the manual for instruction would then be alerted if googling for info.)


« Last Edit: February 01, 2020, 04:59:19 PM by willywombat »

hendrich

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Re: Rohloff spoke lacing uncertainty
« Reply #68 on: February 01, 2020, 04:05:25 PM »
This thread seems appropriate, I would like to thank Mr. Blance for his thorough writings on Rohloff (among other things). We agonized over a tandem purchase from Thorn for a year. We wanted a tandem that would go another bazillion km (our previous) and take us to the middle of nowhere. Mr. Blance was more than helpful to us, as have been his writings concerning a strong bike. For size reasons, we decided on a US maker (well known), but I had my doubts with the wheels on our tandem with Rohloff.

In the 2 years since, we have broken down in the middle of nowhere twice because of broken spokes for exactly the reasons that Mr. Blance made clear in his writings. I wonder/suspect if Rohloff made changes in wheel building based on Thorn information. Finally, after much referral to Mr. Blanceís writings and in my personal conversations with Thorn tandem owners, we got the proper nipples on our third rear wheel (the rims are another concern). I do not wish to bring disrespect to our maker, our new bike is great, but dealing with a Rohloff requires paying close attention to many wheel details, which most experienced wheelbuilders in US are not fully aware of.

This thread and many other threads have been useful in providing Rohloff (and other) information. There is no other bike company (the late Mr. Brown excepted) which provides this kind of detailed information.

Well I donít own a Thorn, but have ordered a bunch of components from SJS. Thanks again Mr. Blance.

macspud

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Re: Rohloff spoke lacing uncertainty
« Reply #69 on: February 02, 2020, 10:09:47 AM »
Sorry Pavel ..you have made a mistake

 ( Macspud made a small error involving one word "wrong" ) but the 2nd photo clearly shows the leading spokes to have heads on the inside of the flange.

Just to clarify :  the leading spoke is the spoke which exits the hub in the direction of wheel travel .

I also noticed you seem to imply earlier that the leading spokes pull the most ..this is not my understanding . As always ..could be wrong .

Perhaps all the confusion isn't aided by people using different/incorrect terminology.

Maybe I would have been better not to use the word "wrong", but Pavel you are incorrect on a couple of points. Trailing spokes pull as power is applied through the pedals, not leading spokes. The trailing spokes in photos 1 & 2 are not mirror images of each other.  The trailing spokes in photo 1 are head in, the trailing spokes in photo 2 are head out.


Remind me to never buy any wheels that you've built up. ;)
 

OK, that is probably a good idea, though not because of any lack in my spatial reasoning. That is sound.  ;)



Another interesting point, the wheels in photos 1 & 2 both have the trailing spokes on the drive side with the heads on the outside of the flange, they also both have the trailing spokes on the non-drive side with the heads on the inside of the flange. I am guessing that this is done due to the hubs being the disc versions, though that is another point that the Rohloff manual covers by saying "Due to the high torsional strength of the hub casing, the use of a reversed lacing pattern on the brake disc side (DB versions) is not necessary.".

I am sure that Thorn builds very good strong wheels and I would get them to build a wheel for me. If I were to build the wheel myself or get a local wheel builder to build the wheel I would follow the instructions in the Rohloff manual and lace it up the same as it is in every photo in the manual. 
« Last Edit: February 02, 2020, 10:22:36 AM by macspud »

willywombat

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Re: Rohloff spoke lacing uncertainty
« Reply #70 on: February 02, 2020, 11:23:36 PM »
MacSpud ..just to clarify ...the reason I said you made a mistake is that by accident, when Pavel stated ( incorrectly )   that all 4 images showed the leading spokes with the heads out ,  you then said :

"Wrong. The first photo is of the non-drive side and has trailing spokes heads in"

the problem was that that statement isn't  actually contradicting his statement !

 He got it wrong on image 2  .
 
So he was wrong  but not for the reason you stated !

Cheers
 
Bill


macspud

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Re: Rohloff spoke lacing uncertainty
« Reply #71 on: February 03, 2020, 05:12:40 AM »
MacSpud ..just to clarify ...the reason I said you made a mistake is that by accident, when Pavel stated ( incorrectly )   that all 4 images showed the leading spokes with the heads out ,  you then said :

"Wrong. The first photo is of the non-drive side and has trailing spokes heads in"

the problem was that that statement isn't  actually contradicting his statement !

 He got it wrong on image 2  .
 
So he was wrong  but not for the reason you stated !

Cheers
 
Bill

 :)

Actually, on closer inspection, we were both correct with those statements. Lol. My statement "The first photo is of the non-drive side and has trailing spokes heads in" is correct. Pavel's statement "all 4 images showed the leading spokes with the heads out" is also correct, though you have to look closely to notice it. Both photos 1 & 2 have the trailing spokes on the drive side with the heads on the outside of the flange, they also both have the trailing spokes on the non-drive side with the heads on the inside of the flange.

I should not have bluntly used the word "wrong" as a sentence. It was harsh.

Anyway, this is true:

Some folks can rotate objects in space in their mind. Some can't. 

I stand by my spatial reasoning.
 ;)



« Last Edit: February 03, 2020, 07:54:31 PM by macspud »

willywombat

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Re: Rohloff spoke lacing uncertainty
« Reply #72 on: February 03, 2020, 10:24:51 AM »
Yes it's true pic 2 shows leading spokes with heads both in and out lol,  I guess I presumed the original comment related to the side that was presented to the camera . 

I've  now contacted SJSC  re sorting  my custom wheelbuild as I need it doing and Rohloff are quiet  and not clarifying anything at the moment . Perhaps they're deciding between Sheldon and Brandt!

Sheldon Brown  remains a personal hero  of mine, I admired his eccentricity ,  his incredible knowledge ,his phenomenal and generous production of tech articles that the layman could understand  ( unlike the " Ornery Prussian " Brandt ....I gave up on his book .I. don't have the brainpower ) .

Oh well ...off to cycle the 10 miles to Exmouth to collect the hub and rim ....my third visit because of this palaver .

I do hope someone with authority will produce a definitive , clear, unambiguous set of instructions but wouldn't put my money on it . Perhaps there's some advantage to it being a grey area  and won't be resolved until other customers  give them earache.

Or maybe I'm wrong 🤔


Danneaux

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Re: Rohloff spoke lacing uncertainty
« Reply #73 on: February 13, 2020, 09:20:50 PM »
Andy has made a 13 February 2020 update to his "Living With A Rohloff" publication to reflect the latest information from Rohloff on spoking.

See page 35 of the publication at this link: http://www.sjscycles.com/thornpdf/ThornLivingWithARohloff.pdf

I've also made access to the link for the latest edition of "Living With A Rohloff" conveniently sticky at the top of the "Rohloff Internal Hub Gears" board, here:
http://thorncyclesforum.co.uk/index.php?topic=13710.0

Best,

Dan.
« Last Edit: February 13, 2020, 09:24:30 PM by Danneaux »

willywombat

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Re: Rohloff spoke lacing uncertainty
« Reply #74 on: February 13, 2020, 10:05:48 PM »
Well ...finally
 .. some genuine notice has been taken of the issues I highlighted when starting this thread. I see Andy has removed the paragraphs I suggested were actually misleading. Now all that is required is that Rohloff themselves provide clear , error free directives themselves !
I emailed Rohloff again on Monday asking for an update on the mistakes in their handbook/ download and whether they intend to  do anything about the confusion.
They have not replied which I think is rather poor as I've put quite a bit of time and effort into getting things resolved.
On a good note ..I personally dropped 2 hubs and rims off at Bridgewater on Tuesday to be built up and unbelievably they arrived today in the post ( 2 days later) beautifully packaged and nicely built ...(of course not in line with the instructions in the most recent download available on the Rohloff website!)
SJSC's also charged a very fair price including return post of both wheels for only £5 extra which was a very nice surprise.
So good on SJSC's and quite frankly shame on Rohloff for not clearing this all up .There are still questions to be answered and points confirmed but they seem reluctant to do so ....Perhaps this is all being attended to  (behind the scenes ).
 In the long run surely I've done them a favour and hopefully clarity will be provided but at the moment get the feeling that the issues highlighted are a nuisance for them and they'd rather ignore them
at least for the time being.