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Thread: Rohloff details

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    Rohloff details

    Anyone know if there is a combination of hubs where one could have Rohloff on the rear and the same spoke length up front. And if not, what is the nearest the spoke lengths would be. I don't know the spoke charts.

    I seem to recall that the Rohloff on 26" is supposed to be laced 2 cross, due to high hub flange. Anyone know if that is correct, and if it stands for the 700c size rims?

    Assume the answer above is they both lace cross 2, is there a problem lacing a hub to a 700C, and later switching it to a 26"? One isn't supposed to mix spoke patterns, but what about rim sizes? The deal is I will probably only ever have the Rohloff I currently have. I was thinking of lacing it to a 700c rim for the moment, but I wouldn't want to rule out the more common 26" use down the road.

    I could take this to a tech forum, but I am not sure the average Rohloff user understands the touring user.

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    The Rohloff site has a lot of info which you can search for answers to your questions.
    Try starting at this spoke length page.
    The Rohloff manual has a lot of spoke length information on pages 42-44.

    My Rohloff hub is laced into Sun Rhyno 26" rims with spokes of length 240mm, my front wheel has a Schmidt SON dynohub and that is laced with spokes of around 260mm.

    I hope this helps.
    Last edited by julk; 10-16-08 at 02:13 AM.

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    Definitely use double-cross on a 26" Rohloff wheel. I've seen triple-cross used on both 26" and 700c Rohloffs and I know it's a mistake on the 26" because it forces the spokes through some nasty angles (particularly at the nipple end), but I'm not sure if the problem would be as bad on a 700c wheel.

    Can I ask why you want both wheels to have the same length of spoke?

    BTW - I consider myself to be an average Rohloff user, and I go touring, I commute, do a bit of off-road, and if nobody's looking I try to do wheelies too. I thought most Rohloff users are 'touring users'. What's not to understand???

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    Right, Rohloff recommends a two-cross pattern because they want the nipple as close to a right angle as possible. If the nipple is too sharply angled it will have a smaller contact area with the rim, which may lead to a crack, and then the rim will fail. I've seen rims fail this way; two wheels, built by me, failed when the rim cracked and the nipples pulled through. But in both cases I think I hadn't tensioned the spokes correctly; neither case was associated with an extreme nipple angle.

    Aside from rim failure (which is, of course, a problem), the extreme nipple angle means the nipple will be harder to turn, making the wheel harder to true; and the spoke may develop a bend near the end of the nipple. I don't see how this is a problem, though.

    In my experience, when spokes fail, it's at the other end. The spoke head comes off. The break usually happens on the bend, one or two mm from the actual head. I have seen this happen many many times, usually on inside spokes, and most commonly on wheels with large flanges. So though I haven't seen it happen with a Rohloff, I don't see why it couldn't. My solution to this problem has been to lace all spokes to the outside of the flange; it's unsightly, but it works. I also like to go for more crosses rather than less. For example, the back wheel of my commuter bike is a 16" (305 mm) rim with a huge Sturmey-Archer 8-speed hub. It came from the factory with 28 2-cross spokes. One day, two months after I got the bike, I discovered three drive side inside spokes had broken, and I didn't have any extras in that size; so I took off all the drive side 2-X spokes and replaced them with the best fit from what I had lying around: this turned out to be 4-X, which is so long that each spoke actually angles toward the center of the hub for about 2 cm from the head; fully 4 cm of spoke are hidden by the flange, and each crosses two others before it even clears the flange. Yes, it is ugly; but I've run those spokes for over a year now, and not one of them has failed; in the mean time I have used several of the take-offs as replacements for the non-drive-side spokes that have failed.

    So... I wouldn't worry too much about the number of crosses. If you are ordering spokes for a specific build, get what the manufacturer recommends, in this case 2-X; but if you have the right size for a 3-X or 4-X build, why not just try it? Worst that can happen is you have to order 2-X spokes and try again.

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    "Can I ask why you want both wheels to have the same length of spoke?"

    It's a slightly practical enhancement with only having to carry one spoke length. That means for the same weight and bulk, more spoke breakage coverage. You can get that with Phil hubs for a cost substantially bellow that required for a Rohloff. Rohloff has other respoking advantages like the better angles and easier insertion. So to really neaten the package to the max, we need some kind of front hub that allows the same spole length to be use.

    "I thought most Rohloff users are 'touring users'. What's not to understand???"

    Touring is a use that doesn't even get attention for decent brakes or groupos. Rohloff, as I understand it is all for the muddy MTB guys, not us. That is why they run with the wrong wheel size and spoke number. For instance they don't get the need for same length spokes or they would be cashing in on a front hub. Phil gets it, one of the few companies that actually makes touring specific products in the key components area.

    Thanks for all the helpful info on spoke lengths folks! I am going to have to futz with spoke calc I guess.

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    Quote Originally Posted by Peterpan1 View Post
    "I thought most Rohloff users are 'touring users'. What's not to understand???"

    Touring is a use that doesn't even get attention for decent brakes or groupos. Rohloff, as I understand it is all for the muddy MTB guys, not us. That is why they run with the wrong wheel size and spoke number. For instance they don't get the need for same length spokes or they would be cashing in on a front hub. Phil gets it, one of the few companies that actually makes touring specific products in the key components area.

    Thanks for all the helpful info on spoke lengths folks! I am going to have to futz with spoke calc I guess.

    I don't think this is true. The hub is very popular with tourers, at least in Europe.

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    Quote Originally Posted by Peterpan1 View Post
    they don't get the need for same length spokes or they would be cashing in on a front hub.
    You'd really rather buy a special front wheel (probably at a much higher than normal price) than carry a couple of spare spokes of two lengths? 4 spokes instead of two? The weight of your extra large flanges would probably be greater than the weight of the two extra spokes!

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    I doubt it's their main sales focus, they don't even have rack mounts on some of the OEM drops. I don't, however know one way or another. A plain guess would be they do 10 times the sales to MTBs, even that sounds low.

    Interestingly there is a touring axle, which would seem to indicate a subset use. The Company has an early association with road and MTB racing including tour de france wins with their chains. So their exact bias isn't all in one aspect of racing.

    The twist shifter doesn't fit drop bars, but does fit mountain bars. Of course tourists use both kinds of bar.

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    I think the vendor in the UK who sells more Rohloff than any other is Thorn - one look at their website will show where their priorities lie, and is probably a good indicator of the distribution of Rohloff use in the country:

    Thorn model range

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    Thanks Al, I'm familiar with Thorn. What Thorn does with Rohloff doesn't change rohloff's priorities when they designed the hub. My reading of Thorn literature would lead me to the opposite conclusion you have come to. Thorn has had to source special 2 piece bars and so forth, to adapt the Rohloff to traditional touring uses. They also recommend/contemplate non-typical gear ratios that void the guarantee. To my mind Thorn proves the reverse point, not the point that is was designed for touring uses. I think Andy Blance has said the same in his info when talking about the unapproved ratios he mentions the lower loading of the hub under touring vs design uses. But that really doesn't mater to me since I have the hub for touring anyway. What I am looking for is info on possible front hub combinations that might be optimal. Back to Spoke calc.

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    "...we need some kind of front hub that allows the same spole length to be use."

    -Nifty idea in theory. If you're going to use a trailer, you could use an "extra wheel" trailer. Set up your front bike wheel, and the trailer wheel as single speed/fixed gear drive wheels (??is it possible to get a fork which accepts rear wheels??). You could have the spare wheels set-up with diiferent drive cogs mounted (one ultra low, one mid range).

    The weight (and obviously the cost) is only outweighed by the type of touring conditions you expect to encounter. Would have 2 spare drive wheels, 2 spare tires, 2 spare rims for the rohloff...Interesting....vy interesting...
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    Quote Originally Posted by Camel View Post
    ??is it possible to get a fork which accepts rear wheels??
    --Surly makes a front fork spaced at 135mm (I had to "Google" to make sure), so there may be others. Vy interesting....

    [edit] Adding: Krikee I had no idea the Rohloff hub flange is so tall! I tried checking spec's for white industries & phill wood, not even close as far as I could tell. Even went into checking track hubs just for fun. Still a nifty idea though!
    Last edited by Camel; 10-16-08 at 08:12 PM.
    mmmm coffeee!

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    There's probably not a front hub in the whole world with a spoke hole circle diameter ~103mm, which is what you'll need for your "one spoke length build". According to Damon Rinard's spocalc hub database, out of 796 hubs the largest front is a drum hub at 90mm. The SON dynamo hub is 70mm. So give up on that idea. It would be kinda dumb to pick a front hub just to fit your spoke length anyway...

    You should follow Julk's earlier post and simply use the Rohloff calculator. Mavic X519 rims with an erd of 540mm laced 2x require 239mm spokes, for example.

    I can recommend DT2.0/1.8mm or Wheelsmith 2.0/1.7mm spokes. Wheelsmith's have a slight weight advantage but this seems like a silly suggestion since you're building a 2300g+ wheel. It will be hard to order only 32-35 spokes, etc due to low demand for that size. Apparently Rohloff sells spokes for this reason.

    Here's what aebike (qbp's actual stock updated daily) has in quantity between 238 and 242mm (use search feature):

    http://aebike.com/page.cfm?PageID=30...nsearch=Search

    Also, Cambria bike sometimes has odd spoke sizes, so check em out.

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    "There's probably not a front hub in the whole world with a spoke hole circle diameter ~103mm, which is what you'll need for your "one spoke length build". According to Damon Rinard's spocalc hub database, out of 796 hubs the largest front is a drum hub at 90mm. The SON dynamo hub is 70mm. So give up on that idea. It would be kinda dumb to pick a front hub just to fit your spoke length anyway..."

    You are probably right. In theory I have a complete machine shop and could machine the required hub. I grant the heft of such an item could be so heavy as to invalidate the product. On the other hand people who like rohloff don't believe hub weight maters that much. I'm not sure how much more it would have to weigh. The tubular connector between the flanges would increase in strength to the square of diameter, and wouldn't need to have much more material in it sectionally than the smaller hub. The flanges by themselves should not be too heavy.

    The advantage to my way of thinking is getting a front wheel nearly as strong as the rear. As well as the spocking.

    I'm surprised anyone makes a 135 mm fork. must look that one up.

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    Quote Originally Posted by Peterpan1 View Post
    Thanks Al, I'm familiar with Thorn. What Thorn does with Rohloff doesn't change rohloff's priorities when they designed the hub. My reading of Thorn literature would lead me to the opposite conclusion you have come to. Thorn has had to source special 2 piece bars and so forth, to adapt the Rohloff to traditional touring uses. They also recommend/contemplate non-typical gear ratios that void the guarantee. To my mind Thorn proves the reverse point, not the point that is was designed for touring uses. I think Andy Blance has said the same in his info when talking about the unapproved ratios he mentions the lower loading of the hub under touring vs design uses. But that really doesn't mater to me since I have the hub for touring anyway. What I am looking for is info on possible front hub combinations that might be optimal. Back to Spoke calc.
    I think you have the wrong interpretation. Thorn probably sells more Rohloff-equipped bikes than all the other bikes shops put together in the Uk and the vast majority of these are Touring/exp bikes. I had a Thorn Raven for loaded touring and Thorn recommends flats for touring although mods, including specialised drops can be used. On mainland Europe many tourists use treking bars with the Rohloff and many German bike manufacturers offer this option.
    The limitations on certain low gears are mainly for tandem use as the ratios offered by the legitimate ratios are more than adequate for the heaviest touring. Thorn are cautious about the amount of torque which can be applied by tandem riders and so the warning.

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    I have to say, it sounds to me like you're doing 20 complicated things in order to do 1 less complex thing. Machining your own hub so you don't have to carry 2 extra spokes on tour....?

    Not to mention that an uncounted number of tourists oh who knows how many tours have done quite well with mismatched front & rear spoke sizes.

    Also, check out the FiberFix spokes, which is an emergency Kevlar spoke. Small, packs easily, re-usable, "one size fits all," in most cases easier to install on the road than a replacement spoke.


    Quote Originally Posted by peterpan1
    The advantage to my way of thinking is getting a front wheel nearly as strong as the rear. As well as the spocking.
    If that's your goal, then use a front wheel with more spokes or a heavier gauge.

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    Quote Originally Posted by Camel View Post
    If you're going to use a trailer, you could use an "extra wheel" trailer. Set up your front bike wheel, and the trailer wheel as single speed/fixed gear drive wheels (??is it possible to get a fork which accepts rear wheels??). You could have the spare wheels set-up with diiferent drive cogs mounted (one ultra low, one mid range)....
    Here's one guy who did that, identical front, rear, trailer wheels, I want to say I've seen blogs of other instances too.

    http://wildworks.co.nz/csr/equipment.php


    edit: I suppose if price is no object you could put a rohloff into all 3 wheels!
    Last edited by HardyWeinberg; 10-17-08 at 10:43 AM.

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    Quote Originally Posted by Peterpan1 View Post
    The advantage to my way of thinking is getting a front wheel nearly as strong as the rear.
    You'd be better off if you thought less and pedaled more. Just build the damn wheel already and go ride. It's really a lot simpler than you imagine.

    As usual -

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    Quote Originally Posted by Peterpan1 View Post
    The advantage to my way of thinking is getting a front wheel nearly as strong as the rear. As well as the spocking.
    I thought the front wheel was already stronger that any rear wheel, not to mention it support less weight than the rear wheel. Has anybody ever broken a front spoke, aside from crashing?
    Erick - www.borealphoto.com/velo

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    Quote Originally Posted by Erick L View Post
    I thought the front wheel was already stronger that any rear wheel, not to mention it support less weight than the rear wheel. Has anybody ever broken a front spoke, aside from crashing?
    It is, in nearly every case; yes, it always does (exception is recumbents); no, it almost never occurs.

    Which explains why avid bicyclists have a collection of front wheels, and usually are building only rear wheels.

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    "I think you have the wrong interpretation. Thorn probably sells more Rohloff-equipped bikes than all the other bikes shops put together in the Uk and the vast majority of these are Touring/exp bikes. I had a Thorn Raven for loaded touring and Thorn recommends flats for touring although mods, including specialised drops can be used. On mainland Europe many tourists use treking bars with the Rohloff and many German bike manufacturers offer this option."

    This really doesn't settle anything unless they are the largest and original intended user for the Rohloff and I see no evidence of that.


    "The limitations on certain low gears are mainly for tandem use as the ratios offered by the legitimate ratios are more than adequate for the heaviest touring. Thorn are cautious about the amount of torque which can be applied by tandem riders and so the warning."

    That's fair, though it isn't me raising the point just picking from Thorn literature. They raise the argument that it is rated for world class athletes at the crossover point to the forbiden ratios. So apparently someone other than the average tourist is intended. At the end of the day, I am charmed and embarassed that my reasons for putting it in this forum rather than a tech one should be of as much interest as the question itself.

    "I thought the front wheel was already stronger that any rear wheel, not to mention it support less weight than the rear wheel. Has anybody ever broken a front spoke, aside from crashing?"

    That's a fair point, though I don't see any reason to accept a limit even if that is true. It's a design feature in some other combinations of hubs, don't really see why it shouldn't be resolved in this case. I think that in most cases if people were offered hubs that could be laced with the same length of spokes, it would be a positive. So far I don't really hear of any reasons it's impossible or any answers to the question that would imply it shouldn't be done. Though I do accept that weight is the obvious shortcoming, but without knowing the actual hub size it will be hard to determine the degree.

    "You'd be better off if you thought less and pedaled more. Just build the damn wheel already and go ride. It's really a lot simpler than you imagine."

    Not a mutually exclusive proposition. It's not like we don't have 10 bikes, or four months of snow, or other interests like metal work, but thanks for the concern.

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    Senior Member onbike 1939's Avatar
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    I know it's a big commitment Peterpan, but it may be that the best course for you to take is just to grit your teeth and buy these two extra spokes. Who knows, the sky may not fall.

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