Yuba, meet Rohloff, and this is Bafang

icicic
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Yuba, meet Rohloff, and this is Bafang

Postby icicic » Fri Mar 10, 2017 4:58 pm

So I have my Yuba, and it's a nice ride, and I've figured how to fit my produce box onto it, which is good.

I also have my new Disc Brakes, which (unfortunately) I might want to trade because of a compatibility issue.

My Rohloff will be in the mail soon, attached to a 26" inch wheel, with a rotor disc, and attached to a bike, a big long bike with a disc brake at the back

And I'm nearly ready to make the purchase that will give me more Baf-ang for my Baf-uck, in the form of a 250W Bafang.

Of course there are problems: the sort associated with starting with almost zero knowledge of tech details for Yuba or Rohloff. And there will be some Bafang tech probs too I suppose.

I hope that, with a bit of help from your good selves, I might solve these soon, and even avoid a few.

First I discovered the four bolt rotor disc quirk that Rohloff has, after I'd bought my Deore XT M8000s, including discs. SO my 180mm M8000 Ice Breaker discs won’t fit and I have developed an impression that the awesomeness of the M8000 system is in the discs as well as the pads, etc, so I’m thinking on what next. I know I can by a Rohloff disc (which I find no reviews for anywhere, or an AVID, or I can get a Magura and pair that with a Magura system, which is supposed to be pretty fine too. Comparable with the M8000s I think.

I’m not a label junkie. get around on my commuter bike with very ordinary v-brakes (Tektro or something) and they’re fine. I wouldn’t usually care so much but, as I may have mentioned in a previous post, this heavy Yuba will be carrying 100 kg of me, and 120 of freight (which adds up to about 440lbs) in a reasonable hilly are with some of the steepest downhills in Sydney. Think San Fran. So I want to know I have good, solid, reliable, stopping power. But still, I dunno. What do you think?

The other hassle is that when I bought the Yuba V4, I didn’t know that, unlike the V5, Yuba were still experimenting with odd hubs and axles. I haven’t had a chance to measure yet but I’m told that they’re oversized, with a 14mm diameter and an odd drop out width too. That freaked me a little but today a Rohlly expert assured me that it’s not that big a deal. Is it? Isn’t it? I don’t know yet.

I considered going with the 21 gear derailleur for now and coming back to the Rohloff option later but later will be a hassle. Also, I want that Rohloff range (equivalent to 27 gears, without repeats) and I really want to be able to change gear if I’ve had to make an emergency or sudden stop while carrying a big load.
I think I actually have my head around the Bafang but I’m sure there are some surprises coming.

Does anyone have any tips about any or all of this?

Cheers,

Rik

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Re: Yuba, meet Rohloff, and this is Bafang

Postby avolve » Sun Mar 12, 2017 8:50 am

The rear drop out is 14mm iirc. And the stock wheel is 48 spoke too...

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Warin
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Re: Yuba, meet Rohloff, and this is Bafang

Postby Warin » Sun Mar 12, 2017 11:14 am

21 gears = 7 x 3 ... most people will be 8 x 3 now. Hovever ...

It is not the number of gears you have but the range .. top to bottom.

And most will be more concerned with the bottom ratio ... that needs to be low enough that you can comfortably get up your hills. Once you have that you will realise that the gap from 1st to 2nd and 3rd can be fairly large ...

You don't really feel like optimising your speed/energy up a hill .. more of a concern when your on the flat - then you want small changes in ratio to optimise your speed/energy.

Top gear? That would be down hill .. a fair proportion of people freewheel down hill ... a bit of a rest from peddling, top does not matter so much.

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Re: Yuba, meet Rohloff, and this is Bafang

Postby RonK » Sun Mar 12, 2017 11:20 am

It will be interesting to see how you are going to gear this thing low enough for the hills you describe with the load you propose without voiding Rohloff's warranty.

I could only just stay within the limits with a loaded touring bike.
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icicic
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Re: Yuba, meet Rohloff, and this is Bafang

Postby icicic » Sun Mar 12, 2017 12:22 pm

avolve wrote:The rear drop out is 14mm iirc. And the stock wheel is 48 spoke too...


Thanks avolve,

So it looks like
Rear Drop Out 14mm
and
Axle Width 19mm
Hub Spacing 130mm.

Does that seem right to you? The width and spacing seems pretty narrow and the Rohloff Owners Manual Spec sheet gives the comparable same specs as

Axle diameter at dropout 9.8mm
and
Total axle width 171mm
Frame Spacing 135mm

If it's correct it makes things interesting. I was planning to DIY the but maybe I'll need an expert to make these work, if they can work.

icicic
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Re: Yuba, meet Rohloff, and this is Bafang

Postby icicic » Sun Mar 12, 2017 10:11 pm

Warin wrote: 21 gears = 7 x 3 ... most people will be 8 x 3 now. Hovever ...

It is not the number of gears you have but the range .. top to bottom.

And most will be more concerned with the bottom ratio ... that needs to be low enough that you can comfortably get up your hills. Once you have that you will realise that the gap from 1st to 2nd and 3rd can be fairly large ...

You don't really feel like optimising your speed/energy up a hill .. more of a concern when your on the flat - then you want small changes in ratio to optimise your speed/energy.

Top gear? That would be down hill .. a fair proportion of people freewheel down hill ... a bit of a rest from peddling, top does not matter so much.



Yes Warin,

the range is what’s important but I think we can agree that the number of gears gives an indication of the range (comparing mtb to mtb gear seats and road to road, etc) and while more people are running 8x3 or 9x3 (or 2 x 10 and 2 x 11) my basic Yuba V4 I bought came with rim brakes and a 3 x7 (a standard sort of SRAM 7 spd 14-28) and, as expected, it does have less range than the 9x3 I rode till recently because there does seem to be a real world relationship between range and standard gears. But maybe there are many more exceptions than I know. I have been riding regularly for a few decades but prior to this project I haven't much considered these technicalities.

Either way, as you said, that “gap from 1st to 2nd and 3rd” can be big. And problematic while carrying a 20 or 40 kg. Because I hope to be able to carry double or triple that, the nice even gaps and smooth transitions of a Rohloff are very attractive, especially with the 536% range that comes without ”large steps between gears or ... awkward gear changes" that you get by extending your range with big rings *.


Re hill climbing performance vs level or downhill performance, I want to rely a bit on the motor to increase uphill speed (without straining my little 250W motor too much) so that I can increase my flat ground and downhill speeds with the front ring. I’m not going for speed records but good speeds for my route. I can drive my route just three times faster than on a 250W mid drive powered Peugeot pizza eBike with 3 speed Nexus IGH. I won’t get to car speed but I’d like to do it in double the time, rather than triple.

The Rohloff is made for mountains and I guess it’s more for getting up them without a motor, then coasting down. As you point out, that is generally more sensible. I don’t have mountains to climb, just hills, and I do have a motor, so I’d like to rely on that motor and a nice small(er) ring to do that.

Hopefully I can find out how much to rely on a little 250W mid-drive. Rohloff already lays down the law about front ring size.


*<https://en.wikipedia.org/wiki/Bicycle_gearing>

Also

www.rohloff.de/en/technology/speedhub/g ... index.html

icicic
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Re: Yuba, meet Rohloff, and this is Bafang

Postby icicic » Sun Mar 12, 2017 10:39 pm

RonK wrote:It will be interesting to see how you are going to gear this thing low enough for the hills you describe with the load you propose without voiding Rohloff's warranty.

I could only just stay within the limits with a loaded touring bike.


How low were you? On the Sheldon Brown page I read that

"Rohloff have calculated that the maximum torque, that the hub will reliably withstand, is slightly more than could be produced by two world class athletes on a tandem using a 38 tooth chainring and a 16 tooth sprocket ... (and this)... is the lowest gearing that they will sanction (which is equivalent to a 22 tooth chainring and a 32 tooth sprocket in a derailleur system.)" The writer of that article (URL below) decided to use a "36 x 17 (11.67% lower than the lowest Rohloff would give warranty for) and had a great time on "2 long-wheelbase eXXp ( e double ex pee) Adventure touring bikes in Tasmania" and has since built a bike with another geared to "39 x 16" *

But he had no motor and I'm guessing you didn't either. I'm not as concerned about getting up the heaviest hills though. I've got to last this week in week out, so I'd rather ride my way around them on the way up. On the way down, if my brakes are up to it, I'll be happy to head down them though. :)

For the last few weeks my riding around big hills and riding up the rest with a 3 spd Nexus and a 250W motor has been fine, with the speed being adequate and getting better as my fitness returns. What I want is higher gears for the flats and moderate downhills, because it's there that I'm running out of gears and finding myself forced to coast at speeds which are just too low.

* http://www.sheldonbrown.com/harris/rohl ... sions.html

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RonK
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Re: Yuba, meet Rohloff, and this is Bafang

Postby RonK » Sun Mar 12, 2017 11:13 pm

icicic wrote:How low were you? On the Sheldon Brown page I read that

"Rohloff have calculated that the maximum torque, that the hub will reliably withstand, is slightly more than could be produced by two world class athletes on a tandem using a 38 tooth chainring and a 16 tooth sprocket ... (and this)... is the lowest gearing that they will sanction (which is equivalent to a 22 tooth chainring and a 32 tooth sprocket in a derailleur system.)"


It doesn't much matter what Sheldon says, it's what Rohloff says that counts. The limiting factor is the weight of the rider. In in your case, since you weigh 100kg,

Smallest permissible sprocket ratios

The primary sprocket ratio used with the Rohloff SPEEDHUB 500/14 (e.g. 42:16) converts the slow rotational speed at the crank into a fast rotational speed at the rear sprocket and reduces the input torque for the Rohloff SPEEDHUB 500/14 in the same proportion. To prevent overstraining the hub, a minimum factor of 1.9 must be used. This minimum factor equates to a primary transmission ratio of:- 40:21, 36:19, 34:18, 32:17, 30:16, 28:15, 26:14 and 26:13. These SPEEDHUB 500/14 ratios resemble a derailleur transmission of 20:40.

Larger chainrings can be used without exceptions.

Attention!

If mounted on a tandem or if the rider weighs over 100kg, the minimum factor of 2.50 must not be undercut. This equates to primary transmission ratios of:- 32:13, 35:14, 38:15, 40:16, 42:17, 45:18, 48:19 and 53:21.


Again, larger chainrings can be used without exceptions.


Find it here: SPROCKET RATIOS.

Oh, and I also thought the close ratios would great, but it didn't work out that way. When you hit a hill you need low gears quickly, not have to change down through a bunch of gears. I found I would frequently have to change down 2, 3 or 4 gears, and it quickly became tiresome.

I now realise that close ratios at the high end and wider ratios at the low end (à la derailleur gears) with is actually a very practical arrangement.

I used 38:17 - significantly lower than you will be allowed - on a touring bike carrying nothing like the 120kg of load you plan to carry, and still found myself walking up hills.

Ultimately I wasn't very impressed with the Rohloff and disposed of it.

Oh, one more thing to consider - putting that much load on a Rohloff hub is going severely stress the housing. Flange failures like this are not uncommon.

Image
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icicic
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Re: Yuba, meet Rohloff, and this is Bafang

Postby icicic » Mon Mar 13, 2017 9:41 am

It’s good to read a critical appraisal of the Rohloff for a change, thanks RonK.


There’s a lot of food for thought there.

Talking about low gears, you wrote “putting that much load on a Rohloff hub is going severely stress the housing. Flange failures like this are not uncommon”. Now, though I’m not planning to go particularly low in my gearing because I planned to rely more on the motor heading up, I wonder if my motor will overstress the housing. I’m not sure where to ask about that but I’ll have to find out.

Re the close ratios becoming tiresome when you hit a hill and frequently had to change down 2, 3 or 4 gears. I’m not sure what the problem was? Was it clunky, slow, physically tiring or something else that bugged you?

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Re: Yuba, meet Rohloff, and this is Bafang

Postby RonK » Mon Mar 13, 2017 10:18 am

No, Rohloff wheels are fragile because of the large flange diameter and because the maximum spoke count is 36.

This means the wheels cannot be laced to a stronger pattern than 2-cross, because the spoke entry angle into the rim is acute and results in spoke failures. Some wheel builders resort to redrilling the spoke holes on a greater angle, but there is only so far you can go with this. A 2-cross lacing cannot take as much torque and may not handle the stress you're going to put on it. I think flange failures probably result from an combination of overloading and overtorquing.

For a wheel which is going to be carrying 100kg rider and 120kg load I would be thinking 40 spokes and a minimum 3-cross lacing, 4-cross would be better.

Rohloff uses a twist shifter. It may take two goes if you need to change down multiple gears. Even on the flats I would usually make a double change as I found the ratios were too close together. It may work for you but you really need to ride one yourself.

Other annoyances - Rohloff is noisy in the lower gears. Rohloff does not shift well under load, particularly from 8th to 7th gears - get it wrong and you'll find yourself stuck in 14th and grinding to a stop.

Plenty of people love them, but I think Rohloff is overpriced, overrated, and far from the glowing image of germanic perfection they are often painted as.
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icicic
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Re: Yuba, meet Rohloff, and this is Bafang

Postby icicic » Mon Mar 13, 2017 11:13 am

RonK wrote:No, Rohloff wheels are fragile ... I think flange failures probably result from an combination of overloading and overtorquing ... I would be thinking 40 spokes and a minimum 3-cross lacing, 4-cross would be better.

Rohloff ...may take two goes if you need to change down multiple gears ... I found the ratios were too close together...

Rohloff does not shift well under load, particularly from 8th to 7th gears ... Rohloff is overpriced, overrated, and far from the glowing image of germanic perfection they are often painted as.



Well RonK I hope I don’t cause a flange failure from overloading and over-torquing. I guess I’ll have to have my original derailleur set up (and original wheel on standby and ready for a quick swap) just in case, and make sure I suss out where all the GoGet vans are along the route.

So you don’t buy the argument that their 36 spoke wheel stability is “almost identical to that of a 48 spoke tandem wheel” *. Rohloff have some pretty diagrams to back up their argument. Is there a table or something other than opinion and anecdote to disprove it?

I know about the 7th and 8th gear change under pressure problem. Was that a change you tended to skip where possible: going from 6 to 9 maybe? Or was that a hassle. If I got stuck in 14 at the wrong time and place more than once or twice I might feel a bit annoyed, though maybe in my case, with a motor, it’d be less of a hassle, given that I an shift to the a better gear while stationary and go again.

Clearly there are some dissatisfied users # but it seems that the dissatisfaction arises out of Rohloff’s big price, big claims and big reputation. I’m glad to read all these stories and approach my first Rohloff with less spectacular expectations. And you’re right when you say that I do just have to ride one myself because in the end it’s about the feel.

My first IGH experience was on a mixte I bought for my wife with an 8 speed Nexus and I find it pretty enjoyable riding. She didn’t think she’d ever love a bike as much as the 1970s Peugeot mixte that I found, stripped and rebuilt for an earlier birthday, but that Chinese mixte with the Nexus 8 is the one she always rides now. My second IGH experience was on a Motorised Peugeot Pizza bike with the 3 speed Nexus. I only bought that to have a few weeks motorised bike experience and to test the 3 speed and Shimano’s Roller brakes. I was surprised that the Nexus 3 was as good as it was when coupled with a motor. I liked it’s range and though I’d have liked another low gear or two, as I think I’ve indicated, I really missed some higher gears to increase speed on flats and downward inclines. Looking at the range comparison put out by Nuvinci^, it looks like the Rohloff will fit the bill.

If it doesn’t, I’ll be glad I bought it half priced and second hand, and I guess I’ll see if I can overcome reservations about the Alfini 11, or look more into the Mountain Triple, or that new (Danish?) hub that’s due out soon. Otherwise, it’s back to the derailleur and hope I don’t have to brake suddenly while heading uphill, etc. Or I go back to fossil fuelled deliveries for now.

* www.rohloff.de/en/technology/workshop/w ... index.html
# https://yacf.co.uk/forum/index.php?topic=37494.0
^ www.simpel.ch/fileadmin/speztooldata/do ... chCard.pdf

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Re: Yuba, meet Rohloff, and this is Bafang

Postby RonK » Mon Mar 13, 2017 11:48 am

icicic wrote:So you don’t buy the argument that their 36 spoke wheel stability is “almost identical to that of a 48 spoke tandem wheel” *. Rohloff have some pretty diagrams to back up their argument. Is there a table or something other than opinion and anecdote to disprove it?

No I don't. The assertion is ludicrous, as I'm sure that any experienced wheel builder could conform.
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icicic
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Re: Yuba, meet Rohloff, and this is Bafang

Postby icicic » Mon Mar 13, 2017 12:39 pm

So you refute their claim but do you have any diagrammatical evidence, tables, formulas or other engineering based, mechanical or technical evidence to refute their evidence?

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Re: Yuba, meet Rohloff, and this is Bafang

Postby RonK » Mon Mar 13, 2017 12:54 pm

No I don't, and I don't have any need to prove or disprove their assertions either way.

I have alerted you to some potential issues. It's entirely up to you what choices you make. Do your research and satisfy yourself that their marketing assertions are correct. Or take them on face value, whatever suits you.

If it works for you, that is great. If it doesn't, there will be no skin off my nose.
Last edited by RonK on Mon Mar 13, 2017 1:25 pm, edited 2 times in total.
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Re: Yuba, meet Rohloff, and this is Bafang

Postby RonK » Mon Mar 13, 2017 1:08 pm

icicic wrote:If it doesn’t, I’ll be glad I bought it half priced and second hand

I missed this before. If you bought an older Rohloff secondhand, it's likely that it's only 32 spoke.

And I note that the stock Yuba wheel is 48 spoke. Surely that rings alarm bells.
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Re: Yuba, meet Rohloff, and this is Bafang

Postby icicic » Mon Mar 13, 2017 1:28 pm

RonK wrote:No I don't, and I don't have any need to prove or disprove their assertions either way.

I have alerted you to some potential issues. It's entirely up to you what choices you make. Do your research and satisfy yourself that their marketing assertions are correct. Or take them on face value, whatever suits you.

If it works for you, that is great. If it doesn't, there will be no skin off my nose.



Well of course you don't need to disprove their assertions but as we're discussing their assertions and as you've already argued against them here (and elsewhere), I thought you might have got around to finding some proof. I'm a disinterested party, not looking to fight but rather, looking for the best product for a particular need and very happy to examine evidence for and against any product or viewpoint here. I already have a large number of files, URLs etc on the subject, a few of which I've already shared with you, and if you had any more evidence I would have been very glad to look at it rather than take anything on face value. And I have already expressed my appreciation for those potential issues you've raised"

Thanks again

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Re: Yuba, meet Rohloff, and this is Bafang

Postby icicic » Mon Mar 13, 2017 1:50 pm

RonK wrote:
icicic wrote:If it doesn’t, I’ll be glad I bought it half priced and second hand

I missed this before. If you bought an older Rohloff secondhand, it's likely that it's only 32 spoke.

And I note that the stock Yuba wheel is 48 spoke. Surely that rings alarm bells.



It is only 32 spoke which is, according to published estimations only equivalent to a 40 spoked dished wheel, if you believe the evidence (which I haven't yet seen refuted), or have faith in the assessment ability of Andy Blance who wrote this report (URL below)*. So I'm not planning to test this particular hub and wheel with a full load (and I may never give it the 200kg lad that it's rated to carry anyway). I just want to see how the Rohloff feels. After that I'll return the wheel it to the bike it came with and either look for another new (or newer) Rohloff (or test another IGH) or consider going back to a derrailieur for this project. So there's really no cause for alarm.

* www.sheldonbrown.com/harris/rohloff-impressions.html

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Re: Yuba, meet Rohloff, and this is Bafang

Postby RonK » Mon Mar 13, 2017 2:31 pm

Yes, I have read much of what has been written by Andy Blance about Rohloff. Andy is one of the proprietors of St John Cycles - the makers of Thorn bikes and probably the main proponent of Rohloff in the UK. His interest is in selling Rohloff-equipped Thorn bikes, and what he says needs to be taken with that in mind.

Do I believe his assertion that the 32-spoke 2-cross Rohloff wheel is as strong as a 48-spoke 4-cross wheel? What he is trying to argue, is that the Rohloff wheel is stronger because it is not dished. But this is a dubious argument versus a wheel which has 16 more spokes.

However I stumbled across a few complaints about Rohloff wheels which aroused my suspicions. So I did my due diligence, spent many hours researching Rohloff and discovered from reports on various forums, blogs and touring journals that wheel failures were not at all uncommon. So absolutely no, I don't believe him.

In fact I bought a pair Rigida (Ryde) Andra CSS rims which were specifically drilled for Rohloff from St John Cycles, as well as various other components for my build. I only found out about them by during my research.

With these rims a wheelbuilder who is expert at tensioning and stress-relieving can build a wheel strong enough for common touring loads. But I still do not believe it will be anything like as strong as a 48-spoke wheel.

And of course the issue of flanges cracking remains.
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Re: Yuba, meet Rohloff, and this is Bafang

Postby icicic » Mon Mar 13, 2017 3:49 pm

Yes, his bias is there, and the hubs are not complaint free.

Thanks again

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Re: Yuba, meet Rohloff, and this is Bafang

Postby RonK » Mon Mar 13, 2017 3:57 pm

One more piece of advice to consider, if you choose to persist with the Rohloff.

Select a chainring/sprocket combination that avoids using the lower 7 gears as much as possible.

10th gear is direct drive - no noise, no friction losses, so it makes sense to gear the bike to use 10th gear at normal cruising pace.

The combination I used let me ride my touring bike comfortable at around 22kph in 10th gear, so I only needed to shift to the lower 7 on decent rises.
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Re: Yuba, meet Rohloff, and this is Bafang

Postby icicic » Mon Mar 13, 2017 5:09 pm

RonK wrote:One more piece of advice to consider, if you choose to persist with the Rohloff.

Select a chainring/sprocket combination that avoids using the lower 7 gears as much as possible.

10th gear is direct drive - no noise, no friction losses, so it makes sense to gear the bike to use 10th gear at normal cruising pace.

The combination I used let me ride my touring bike comfortable at around 22kph in 10th gear, so I only needed to shift to the lower 7 on decent rises.


That is great advice, thanks. On my 21 spd Yuba at present (with no motor and no load) I find myself in the top gear most of the time front big ring and on 6 and 7. I hope to keep high and I do like direct drive on my 3 spd.

Given that I'm motorising, can you recommend someone to speak to re front ring sizes. 44 teeth seems standard for the motor, and I guess it'll be something to feel my way through, but I'd like some experienced advice up front.

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Re: Yuba, meet Rohloff, and this is Bafang

Postby paulmoir » Wed May 03, 2017 6:27 pm

COMMON ROHLOFF SPEEDHUB MISPERCEPTIONS

My name is Paul Moir and we are the authorised Australian distributor/service centre for Rohloff. Whilst I don't normally respond to forum posts, I thought it was only fair to clarify some inaccuracies posted for Rik's (and others) future knowledge. The Rohloff Speedhub has an excellent reputation worldwide and its build quality and reliability are unmatched.... hence why it is regarded globally as the "gold standard" hub for touring bikes. I've been using Rohloffs since 2004, including downhill racing and have never had an issue. Being the Australian Rohloff service centre I have replaced a number of Rohloff hub shells and whilst not a "tandem only" issue... all flange failures have been with tandems or very heavily loaded bikes (eg. 100kg rider, plus another 80kg being carried). And most are due to using the wrong spokes, poorly/incorrect tensioned spokes or laced wrong.

Below is a response to most issues/concerns raised, which I hope are helpful for the future.

SPEEDHUB GEAR CHANGING
Changing gears with the Rohloff Speedhub between 7 and 8, or indeed any gear is easily done if one accepts that the SPEEDHUB is a completely different transmission to anything else on the market. As such, the Speedhub needs to be shifted slightly differently (that is, reducing pressure as one shifts rather than slightly after as with a derailleur setup). When shifted correctly, the shift process is smooth although it will take a little while to learn initially - after which, the shifting process will become second nature… just like reducing pressure when shifting a derailleur system.

With reference to using only the higher gears, I have personally never heard of this before. Plus the equal spaced gears are one of the benefits of the Rohloff, so again the comments against this I have never heard before. The gear changing, the spacing of gears and simplicity of using the complete Rohloff Speedhub gear range has always been one of the big positives. The bottom line is that the Rohloff sells, and continues to keep selling, because it is a high-quality and ultra reliable product (understanding there may be others with different opinions).

FLANGE FAILURES
Flange failures are not common, but have occurred with heavily loaded bicycles. The problems of incorrect spoke choice, spoke quality and spoke tension increase with bicycle load. So Speedhubs mounted on tandems, heavily laden touring and cargo bikes are far more likely to have a flange fail, compared to a well maintained and correctly built Rohloff Speedhub wheel in a light commuter rig.
Rohloff redesigned the Speedhub shell flange in early 2014. The design change was minor and can only be confirmed by measurement or serial number. All Speedhub shells after these serial numbers will have the new and strengthened flange design (196922 – 32 hole silver, 198454 – 36 hole silver, 196521 – 36 hole black, 196713 – 32 hole black, 197520 – 32 hole red and 197980 – 36 hole red).
In mid 2015, Rohloff also released the Flange Support Rings for heavy duty applications. The Flange Support Rings are now supplied standard with all Rohloff Tandem Speedhubs. These rings ensure that even if a flange break occurs, the material cannot break away and therefore the spoke tension can be maintained.

Image
https://www.rohloff-au.com/new-products

The correct spoke choice and maintaining the minimum 100kgf spoke tension (100kgf/1000N inflated tyre, 130kgf/1300N without tyre) is fundamental in maintaining a trouble-free Speedhub wheel.

SPEEDHUB WHEEL STRENGTH & STABILITY
When the Rohloff SPEEDHUB 500/14 is built up (32 or 36 spoke wheel), it is considerably stronger than typical 36 spoke wheels. The stability is similar to that of a 48 spoke tandem wheel. The spoke flanges of the Rohloff SPEEDHUB 500/14 are constructed symmetrically. This allows all spokes to be at the same angle on both sides of the finished wheel, which results in a much stronger wheel due to the evenly distributed spoke tension. To build a strong Rohloff wheel, the spokes must be tensioned to a minimum of 1000N (with inflated tire). The typical derailleur rear wheel needs to be dished to accommodate the room required by the cassette…. this creates a huge difference in spoke tension. The tension on the dished side is usually considerably higher (over 1200N) and this can lead to problems with the spoke nipples sitting correctly within their seats in the rim (see photo below, pretension in the "8-speed rear hub" here is only 600N).

Image

Due to the increased diameter of the hub flanges and PCD of the Rohloff SPEEDHUB 500/14, the spokes need cross only two times, but do so roughly at the same angle as a three cross lacing pattern on smaller flanged hubs. There is less load on the spokes because of the large flange PCD diameter and the hub flange is subjected to lower forces because these spokes pull further away from the axle center, creating a better lever to pull the wheel around (torque = force x lever length). Same photo above shows the maximum spoke loads (numbers in brackets are the pre-tensioned forces of spokes after lacing).

WHEEL LACING PATTERNS
As explained, the more often a spoke crosses, the force from the rim will be directed into the flange further outward thus having less direct influence on flange stability. The greater angle created however will cause the spoke to enter the rim at a more obtuse angle. Rims are drilled to permit a certain amount of nipple movement so that the route from spoke to nipple remains as straight as possible. If the spoke entry angle is too obtuse, spokes will kink at the nipple join and this kink will lead to premature spoke failure. The situation is made worse when using hubs with a large spoke P.C.D. such as the Rohloff Speedhub and worse still when using modern rims with eyelets - where eyelets are reduced in diameter below 4.4mm (to save vital steel weight) so that the nipple has even less space to angle itself in the direction of the spoke. The ideal spoke lacing pattern for the Rohloff Speedhub wheel is actually 1-cross, although our customers would not accept this when the Speedhub was first introduced. Hence our recommendation remains a 2-cross lacing pattern for wheels of 26 inch diameter and larger (see image link below showing the spoke entry angle for a 1-cross Speedhub wheel laid over that for a typical 3-cross derailleur wheel).

https://www.facebook.com/rohloffaustralia/photos/pcb.219140375246148/219129985247187/?type=3&theater

The examples shown in the image attached of the 3-lacing patterns are for a 20 inch wheel (as originally drawn in full-size). The fact that the angle increases with the number of spoke crosses however, remains the same regardless of wheel diameter (note that the spoke entry angle for a 1-cross, 26 inch Speedhub wheel is 5.0° and a 3-cross, 26 inch derailleur wheel is 4.5°).
As you can see, the 1-cross Speedhub and 3-cross derailleur spoke angles are identical and therefore both offer equal flange stability if laced and tensioned with the correct spokes. The Speedhub however remains the laterally stronger wheel of the two, due to the equal spoke length and symmetrical lacing of the undished wheel (this permits even spoke tension throughout the build).

Hope this is of help, please feel free to ask any further questions, cheers Paul.
https://www.facebook.com/rohloffaustralia/
https://www.rohloff-au.com/

icicic
Posts: 43
Joined: Tue May 22, 2007 1:10 pm

Re: Yuba, meet Rohloff, and this is Bafang

Postby icicic » Wed May 03, 2017 10:57 pm

Thanks for that very detailed response Paul. It's all good information. I've been riding my Yuba Mundo Cargo Bike with Bafang Electric Motor and Rohloff Speedhub a few times a week now for the past six weeks and, despite the fact that I still haven't set it up properly, it's been great carrying me (100kg) and another 30 or 50kg up and down hills in Sydney's east. I was out riding for about two and a half hours this afternoon/evening and I'll be out for another hour or so early tomorrow morning. I still have to install the Bafang gear sensor to make for easier riding and I still have to sort out my disc brakes and retire the v-brakes that I'm using in the meanwhile.

Even without the gear sensor, I'm loving the gear changing of the Rohloff. And though I think I'll need to opt for a larger gear ring (having opted to try the smallest Bling Ring) I am loving the gear range. It's so much better than the range of gears I'm used to riding, allowing me to carry a fair bit of weight up some good hills, but still giving me somewhere to go on the flats and slight downhills. I put this Cargo bike set up together to test the motor and Rohloff combination before I committed more money to a Cargo tricycle and I'm well and truly convinced.

So, now I'm looking at trikes, I'm also exploring a couple of areas I've not yet explored, in the interest of greater mechanical power. I'm carrying cargo after all. One is the idea of a raised recumbent because I'm led to believe that recumbents can maximise power but I have zero interest in putting myself at bumper bar height. And while looking at recumbents, I came across one which combined a Rohloff with a Schlumpf Drive. Do you know anything about combining these?

Trevtassie
Posts: 560
Joined: Sun Jun 28, 2015 10:57 am

Re: Yuba, meet Rohloff, and this is Bafang

Postby Trevtassie » Wed May 03, 2017 11:26 pm

Ah, bugger it, just realised the wheel I bought is laced wrong, leading spokes are head out...dang... oh well, re-lace it tomorrow.

icicic
Posts: 43
Joined: Tue May 22, 2007 1:10 pm

Re: Yuba, meet Rohloff, and this is Bafang

Postby icicic » Thu May 04, 2017 9:17 am

Trevtassie wrote:Ah, bugger it, just realised the wheel I bought is laced wrong, leading spokes are head out...dang... oh well, re-lace it tomorrow.


Well that sucks a little. I've been meaning to check mine - since I bought it. Given that it's only a 32 hole, and I'm carrying some weight, I think I'd better get around to it.

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