@[mention=4]flecc[/mention] Isn't it possible that Kalkhoff decided not to include the gear change easement facility in their high-end model because the NuVinci Harmony system doesn't actually change gears in the same way as a Shimano Nexus hub?

 

It still seems to me that, given my choice, and given the information I've been able to collect, the NuVinci-based system is the way to go.

 

Yes, I'm sure that is the reason with the NuVinci and suspected as much simply since there are no fixed change points to work from. It needed checking though, just in case they had been cunning enough to have the system recognise a sudden change in torque applied due to a ratio change being attempted.

 

My instinct, like yours, is that the NuVinci would stand the combined torque. However, that's not the whole story. As d8veh has merntioned, at high input forces the ratio change becomes difficult to force by hand on the manual model as I know from trying one. That raises the question whether the Harmony's automatic system, which I've never tried, could manage a change when a very high pedal and motor input is being applied.

 

Of course with the manual NuVinci the input could be manually eased just before changing ratio, but that wouldn't be possible on the automatic Harmony, not knowing when it was trying to change.

.

@[mention=4]flecc[/mention]

While I think about, I'm wondering if the single issue of the regular Shimano Nexus hub's fragility and my weight/hard riding could explain all the drive train problems I experienced with my 2012 Kalkhoff Impulse Agattu C8 XXL, or whether the motor, wheel/chain adjustment and brake issues indicate that I had a bad bike or there were some maintenance issues I'm not aware of. The bike is supposed to be designed to carry a 170kg rider, hence the "XXL".

 

@[uSER=330]Cyclezee[/uSER] If the Kalkoff Impulse Ergo XXL bike with the NuVinci Harmony system turns out not to be able to handle the demands I put on it (just commuting up and down some hills with not particularly huge grades, at decent speeds, carrying me, my shopping, whatever, then I guess it's back to square one and I'll need to do more research on what e-bike system is rugged enough apart from a hub motor/derailleur solution.

 

I wonder if that might well be the problem too. You wrote up the page that down changes resulted in loud clunks, and that must be doing damage. I find that changes with my Nexus 8 are pretty smooth and quiet. But I am deliberate and careful to feed power in slowly with soft pedaling after a change. I don't ride it like my old derailleur road bikes and just snick the gears in without changing cadance.

 

I can only wish I had access to a mechanic who could undertake such advanced work. Doing that myself is way beyond my skill-set. What would you say to the mechanic who pulled my bike out of service because the frame had worn down at where the wheels is attached (a long patch on the stay where it was worn down to bear aluminium)? Could you have proposed a resolution?

 

It really wasn't advanced in any way. I just cleaned the contact surfaces, and in my case sanded off some alloy which had come off the non rotation washer to get a good surface. I recut the washer with a junior hacksaw but I could just as easily have bought a new one.

 

I reasoned that Kalkhoff wouldn't sell a bike on which it was impossible to keep chain tension. So just put the wheel back to their spec with good contact surfaces. I do have a torque wrench but even so I used to rebuild motor bike engines without one decades ago and it is possible to judge torque fairly accurately with a little practise.

 

My bike was about a year old when I bought it and the first owner probably had a similar problem and tightened the wheel up too tight. Which of course just damaged the washer surface and made it worse. Overtightening like that is a natural reaction to wheel slippage and it will wreck the dropouts and frame eventually.

Edited October 5, 201411 yr by JohnCade

Hi @[mention=9180]JohnCade[/mention],

 

When I first bought a Shimano hub gear-equipped bike, I was told to stop pedalling when I change gears. That's what I've always done since. Even going up hill, I stopped pedalling and changed gears, waited a beat, then resumed pedalling. Even in situations where I heard the big chunk, that followed me stopping pedalling, changing the gear, waiting, then starting to pedal from a standing start. The only explanation for there being any point where both my pedalling and the motor were actively putting tension on the hub would be if the change was much slower than I anticipated. As I read your post, I think the only difference was that I didn't pedal softly after a change, figuring that the change would have already been effected. Is this idea that one should leave a Shimano Nexus hub a long, long time to change and pedal very softly after changing a general piece of advice? If so, I've never heard that. But it is true that most of my life I used derailleur gear systems.

 

I wonder if that might well be the problem too. You wrote up the page that down changes resulted in loud clunks, and that must be doing damage. I find that changes with my Nexus 8 are pretty smooth and quiet. But I am deliberate and careful to feed power in slowly with soft pedaling after a change. I don't ride it like my old derailleur road bikes and just snick the gears in without changing cadance.

@[mention=4]flecc[/mention] From all my reading about the NuVinci, there are no discontinuous points, the gear range is infinite. So what would Kalkhoff work from, to detect a change? From what I understand, unlike a Shimano Nexus hub and a whole range of others, there are no step changes in the gears, so there are much fewer torque impacts on the hub. There's a lot online about how the NuVinci hub is a better match for a crank-drive electric bike. Having never used one, I can't evaluate this difficulty in effecting a change in ratio at high levels of torque. I haven't seen anyone confirming that this is an issue, either, with the particular version of the NuVinci Harmony Advanced that is sold with the Kalkhoff Ergo XXL.

 

I won't have any opportunity to try before I buy. Both the Kalkhoff Ergo XXL and the Kalkhoff Agattu XXL are models that are much higher up the range than what the shop carries in-store. These models must be special-ordered from Kalkhoff. I suppose if I find that the gears don't change down when I'm climbing a hill, I'll have reason to return it and possibly opt for that refund.

 

 

Yes, I'm sure that is the reason with the NuVinci and suspected as much simply since there are no fixed change points to work from. It needed checking though, just in case they had been cunning enough to have the system recognise a sudden change in torque applied due to a ratio change being attempted.

 

My instinct, like yours, is that the NuVinci would stand the combined torque. However, that's not the whole story. As d8veh has merntioned, at high input forces the ratio change becomes difficult to force by hand on the manual model as I know from trying one. That raises the question whether the Harmony's automatic system, which I've never tried, could manage a change when a very high pedal and motor input is being applied.

 

Of course with the manual NuVinci the input could be manually eased just before changing ratio, but that wouldn't be possible on the automatic Harmony, not knowing when it was trying to change.

.

Apparently, the rear wheel had been taken off the bike so often that the portion of the frame the wheel attaches to had worn, making it impossible to properly tighten.

 

KTM crank drive hub geared bikes suffer the exact same issue. KTM know about it but like to give the impression all is fine and they know best.

 

Like Wissy I'm past wasting my time engaging with KTM UK, as all they want to do is to try and look like they care. The sad fact is that once they've had your money they don't want to know.

 

I fitted a tensioner very early on in the bikes life to avoid the issue you have now. Chain adjustment now takes seconds to do. I've asked KTM to include an adjuster on their hub geared bikes, my feed-back has been dismissed in a very offhand we know best attitude by FLI, no surprises there.

 

@[mention=2339]Artstu[/mention] Thanks for your input. Glad I'm not alone, but I wish I'd known that that Kalkhoff bikes were prone to this. How did you manage to acquire and fit an aftermarket chain tensioner? I asked my retailer and Kalkhoff repeatedly directly about that possibility, only to be told there was no chain tensioner to be fitted. It would have made such a difference: I constantly struggled to fit the wheel, but you were supposed to pull on the wheel just the right amount while tightening the wheel some unspecified amount. I just couldn't figure it out. Even if I had a torque wrench, I wouldn't have known what level of torque to apply. Doing it essentially one handed on two sides of the axle? I guess a good bike mechanic knows how, but I'm figuring that more than one of the bike mechanics (not always the dealer's mechanics) who serviced my bike way overtightened the wheel. Once that damage to the frame was done, there seemed to be nothing to be done about it but declare the bike a write-off. I couldn't believe how easy it seemed to be to destroy the bike's utility.

 

One thing I haven't said so far is that I'm pretty pissed off with Kalkhoff. They offer a product that gets great reviews, but woe betide you if you have any problems. Unhelpful customer service (ask your dealer), incredibly long delays in sending replacement parts, seemingly no regard for the customer experience. They seem to assume i'm some recreational cyclist who does the odd weekend cycling run in fine weather who won't miss his bike for several months at a time. That's not me.

KTM crank drive hub geared bikes suffer the exact same issue. KTM know about it but like to give the impression all is fine and they know best.

 

Like Wissy I'm past wasting my time engaging with KTM UK, as all they want to do is to try and look like they care. The sad fact is that once they've had your money they don't want to know.

 

I fitted a tensioner very early on in the bikes life to avoid the issue you have now. Chain adjustment now takes seconds to do. I've asked KTM to include an adjuster on their hub geared bikes, my feed-back has been dismissed in a very offhand we know best attitude by FLI, no surprises there.

 

[ATTACH=full]9711[/ATTACH]

 

I think the problem is that the companies are used to making bikes and they haven't all adjusted to the slightly different needs of e bikes. The combined power of motor and rider puts more tension on the chain, and while the wheel fixing is fine for an unpowered bike it can pull it forward on an e bike if not perfectly fitted and correctly torqued.

 

You can get adjusters similar to motor bike wheel ones for rear facing dropouts often used on fixed wheel bikes, and I have seen some which would fit the Kalkhoff and Bosch dropouts too. But would the kind of chain tensioner fitted here help much apart from preventing slack and possible chain jumping? The chain would still pull forward on the drive side and put the wheel out of line with that if it was going to I should think. They're mainly meant to take up the slack with hub gears in vertical dropouts where chain adjustment isn't possible.

Edited October 5, 201411 yr by JohnCade

@[mention=2339]Artstu[/mention] Thanks for your input. Glad I'm not alone, but I wish I'd known that that Kalkhoff bikes were prone to this. How did you manage to acquire and fit an aftermarket chain tensioner? I asked my retailer and Kalkhoff repeatedly directly about that possibility, only to be told there was no chain tensioner to be fitted. It would have made such a difference: I constantly struggled to fit the wheel, but you were supposed to pull on the wheel just the right amount while tightening the wheel some unspecified amount. I just couldn't figure it out. Even if I had a torque wrench, I wouldn't have known what level of torque to apply. Doing it essentially one handed on two sides of the axle? I guess a good bike mechanic knows how, but I'm figuring that more than one of the bike mechanics (not always the dealer's mechanics) who serviced my bike way overtightened the wheel. Once that damage to the frame was done, there seemed to be nothing to be done about it but declare the bike a write-off. I couldn't believe how easy it seemed to be to destroy the bike's utility.

 

One thing I haven't said so far is that I'm pretty pissed off with Kalkhoff. They offer a product that gets great reviews, but woe betide you if you have any problems. Unhelpful customer service (ask your dealer), incredibly long delays in sending replacement parts, seemingly no regard for the customer experience. They seem to assume i'm some recreational cyclist who does the odd weekend cycling run in fine weather who won't miss his bike for several months at a time. That's not me.

 

I've just ordered one of these to try out on my Kalkhoff Sahel Compact. I have to adjust the chain tension frequently by moving the wheel so thought this might be worth a try. On offer too at the moment.

 

http://www.chainreactioncycles.com/shimano-alfine-chain-tensioner-s510/rp-prod46334

@[mention=4]flecc[/mention] So what would Kalkhoff work from, to detect a change?

 

I haven't seen anyone confirming that this is an issue, either, with the particular version of the NuVinci Harmony Advanced that is sold with the Kalkhoff Ergo XXL.

 

 

I already told you that the Harmony that I tried wouldn't change down to go up a hill. I tried the manual change too. It was a waste of space for a heavy guy like me. Alex tried it after me, and it worked perfectly for him, but 30kg is a big difference.

 

They could use a cable sensor to cut the power while changing just like the "hidden wire" brake sensors cut the power when you apply the brakes.

 

Go and try a Harmony to see if it works for you. Then you have your definitive answer. I wouldn't get too excited about it until you've tried it. Make sure you try it on some hills.

Hi @[mention=9180]JohnCade[/mention],

 

When I first bought a Shimano hub gear-equipped bike, I was told to stop pedalling when I change gears. That's what I've always done since. Even going up hill, I stopped pedalling and changed gears, waited a beat, then resumed pedalling. Even in situations where I heard the big chunk, that followed me stopping pedalling, changing the gear, waiting, then starting to pedal from a standing start. The only explanation for there being any point where both my pedalling and the motor were actively putting tension on the hub would be if the change was much slower than I anticipated. As I read your post, I think the only difference was that I didn't pedal softly after a change, figuring that the change would have already been effected. Is this idea that one should leave a Shimano Nexus hub a long, long time to change and pedal very softly after changing a general piece of advice? If so, I've never heard that. But it is true that most of my life I used derailleur gear systems.

 

I think it's the application of full power too quickly that causes clunking. I don't know exactly how the Nexus works but I get the impression from riding it that the change is completed upon gear rotation. So I soft pedal a part crank turn until I feel it's fully engaged before I use full power.

I've just ordered one of these to try out on my Kalkhoff Sahel Compact. I have to adjust the chain tension frequently by moving the wheel so thought this might be worth a try. On offer too at the moment.

 

As far as I'm aware they still don't make a tensioner for horizontal drop-outs. Therefore the tab that fits into the vertical drop-out needs removing before it will work. I managed to cut mine off with a hacksaw.

Mine also fits snugly in the drop out area with the edge of the tensioner snug up against a raised area. I've had no issues at all of the wheel ever moving since.

 

Tensioning the chain before was very very tricky, not helped by the rear stays not being equal on both sides, so it was very difficult to judge if the wheel was inline. Getting the tension required the wheel to be nipped up at an angle with one side nipped up, and then the wheel straightened and the other side tightened.

 

I only did that once before fitting the tensioner, I just knew it would destroy the drop-out area in no time at all.

 

Alex fitted better quality nuts to allow a tighter fit, I've managed okay with the standard nuts, but they are poor quality and easy to strip the thrreads.

I think it's the application of full power too quickly that causes clunking. I don't know exactly how the Nexus works but I get the impression from riding it that the change is completed upon gear rotation. So I soft pedal a part crank turn until I feel it's fully engaged before I use full power.

 

A full pause is best, you can hear when the change has been made. My Bosch motor has a soft start too, but I'm sure anyone with mechanical sympathy would be okay with a deralliuer style motor.

A full pause is best, you can hear when the change has been made. My Bosch motor has a soft start too, but I'm sure anyone with mechanical sympathy would be okay with a deralliuer style motor.

 

Probably didn't make myself clear. I stop pedaling when changing of course, but soft pedal when resuming a part turn to make sure it's fully engaged before giving any power again.

 

One thing I haven't said so far is that I'm pretty pissed off with Kalkhoff. They offer a product that gets great reviews, but woe betide you if you have any problems. Unhelpful customer service (ask your dealer), incredibly long delays in sending replacement parts, seemingly no regard for the customer experience. They seem to assume i'm some recreational cyclist who does the odd weekend cycling run in fine weather who won't miss his bike for several months at a time. That's not me.

 

I don't know how often you look here but there are a lot of threads complaining about the service of the main brands when things go wrong. The problem is the old fashioned way the warranty arrangements are left entirely up to the dealer. With the dealer being the factory customer rather than the end buyer.

 

To use as an example a manufacturer who makes both bikes and motorbikes a KTM motorbike buyer will have a very different warranty experience to a KTM e bike buyer if things go wrong with it.

Cwah....as promised I would check our spares stocks,I have good stocks of 26" Tornado and Arriba wheels with the BPM motor laced in,price £100.00 plus £8.50 carriage plus vat.

The cassette mounting on the Arriba and Tornado are different,if you wish to order either please telephone Kudos and we will explain the differences and you can make your choice.

KudosDave

As far as I'm aware they still don't make a tensioner for horizontal drop-outs.

 

.

There are some Evans Cycles sell this one

.

@[uSER=4366]d8veh[/uSER] Thanks for your post. I remember you telling me about your experience with the Ergo XXL. What I meant by "confirming" is that another person would tell me they had the same experience. Your experience could have been down to the bike you tested. I don't really have much of an option if there are serious flaws with all of Kalkhoff's XXL bikes for heavier riders. Unfortunately, if I order the bike, my first test will be riding it home. To find a hill, I just turn left.

.

There are some Evans Cycles sell this one

.

 

I did actually mean an Alfine one like in the link, but to suit a horizontal drop out, as opposed to a vertical drop out.

If the bike has a derailleur hanger then there are lots of options available.

Understood, but the devices I posted on are like motorcycles ones and I think so much simpler than having a dirt collecting jockey wheel.

 

As well as keeping the wheel in place, they are also a great aid to adjusting a chain to the correct tension.

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A nice option for a track bike with rear facing drop outs. but not much good on the majority of bikes with forward facing drop outs I imagine. I doubt they'd actually fit on my bike, if they did they'd be less than ideal with the adjuster screws acting on the curved rear section of my frame.

 

Unlike mine

http://upload.wikimedia.org/wikipedia/commons/3/36/Horizontal_rear_dropout.jpg

I understand that, but they will work on quite a few bikes with forward opening slots, the bolts used against the curved rear section of the frame dropout. On most frames the bolts sit against symmetrical upper and lower curves so happily stay in place. It just means the adjustment of the two bolts must be alternated in small steps and the adjustment range isn't great.

 

Only those frames with lots of plate length behind the slot or an odd rear shape can't accommodate them at all.

.

I looked at those a little while ago and I'm pretty sure they won't fit the forward sloping dropouts on my bike or Artstu's. I did see these on youtube when I was looking then too and they are designed for the Nexus with room for the non rotation washer to fit. I might try to track them down as they would be perfect for adjusting the wheel if nothing else.

 

http://en.hollandbikeshop.com/branded-bicycle-parts/batavus-bicycle-parts/batavus-chain-tensioner/batavus-chain-tensioner-short-stainless/

 

http://www.singlespeedshop.com/Singlespeed---Fixed-Gear/Kettenspanner/Batavus-Chain-Tensioner---Kettenspannerpaar.html

 

You only need one on the chain side. There's no tension on the other side if the chain side is held.

Thanks d8 that looks like the one. Seeing it off the bike the non rotation washer will be up against the smooth surface of the tensioner. So unless another washer was used between the tensioner and the frame it would be pretty hard to get good holding friction and the chain tensioner would be what was mostly holding the wheel back.

 

One site specifies these as for steel frames only as well. I might ring the Dutch Bike shop in Littlehampton who posted the video and see what they think and if they have any.

Edited October 6, 201411 yr by JohnCade

I have successfully overcome wear on the early ProConnect frame with the stainless steel Surly Hurdy Gurdy chain tensioner. This works well with the forward facing drop out BUT sadly does not come with the necessary flat to act as the non-rotation washer on the chain side of a Nexus hub.

 

In my case, using a Rohloff hub, the Hurdy Gurdy is on the chain side and a long/substantial torque arm prevents rotation on the non-chain side.

 

Typically the Nexus hub will be using the Black/Silver pair of Shimano non-rotation washers with forward facing dropouts; one on each side of the frame. It may be sufficient to use only the one on the non-chain side.

 

The insert washer supplied with the Hurdy Gurdy is only appropriate to wheels secured with quick release spindles.