Bosch Motor shutdown, Error 503, get you home only.

[vfr400]

Real life experience:-
I frequently ride my crank driver about 1.5 miles up a very gentle slope that once was a railway line. Probably about 1 in 200.
If I come up in 8th (top) gear I can do 13 mph without pedalling. The motor feels warm to the hand.
If I use 7th gear, the speed remains the same and again the motor is warm.
If I use 6th gear the speed is still the same but the motor is cooler.
I suspect that the motor is more efficient in the lower gear and losing less electricity making heat.
My hub motor cannot do that.

What you're saying is that in some circumstances, your motor is more efficient than at other times. You didn't actually measure its efficiency. You have to consider that your bike goes through a range of conditions during a typical ride. Do you know at what RPM, your motor develops maximum efficiency and what proportion of time you spend pedalling at exactly that speed?

When I did my tests, I had two similar motors with identical controllers, similar weight riders travelling side by side over journeys around 30 miles over varying moderately hilly terrain. Both bikes were fitted with wattmeters to measure consumption. On one bike, the motor drove the crank via a chain, and the other drove the rear wheel directly.

 

[Ocsid]

Do not make the mistake of assuming that electric motors are similar in any way to motors that burn say petrol or diesel, especially with regard to torque and RPM.

Regards
Andy

First of all what I clearly was discussing was efficiency in respect to speed of the motor, and how this impacts on road speeds depending on gearing.
Be very sure I am not “assuming that electric motors are similar in any way to motors that burn say petrol or diesel, especially with regard to torque and RPM.”

So back to what I spoke about, efficiency vs rpm.

The document you referenced, as you said “explains the subject rather well in my opinion” , at least the subject I discussed, as I explain:

Figure 4 of the document shows that the motors, as I expected, have a parabolic efficiency vs rpm curve, indeed a whole nest of varying power curves reflecting the voltage applied, Figure 15. The example given peaking at 60-65% at maximum power.

Note it clearly endorses what I said “Logic has it that any motor efficiency curve must diminish towards its lower revs, as stalled the efficiency has to be zero, power goes in but none comes out.”

Thus that motor in a hub,without any gearing change features, has a unique road speed where it has the potential to yield peak full power efficiency.
On the other hand, that same technology motor if used where multiple ratio gearing options are featured, has the same number of road speeds where the peak full power efficiency is available, as the number of ratios in the gearing.

It is true a single epicycle fixed gear ratio in a hub drive offers the potential for a higher mechanical efficiency than a crank drive and dérailleur set up, so a higher overall power efficiency, but it is confined to being available at just a single road speed .
Whereas, with the crank drive and geared ratios, sometimes as many as 21, then it has 21 peak efficiency points spread across the whole spectrum of road speeds. Offering “better” ability if needed to meet the loading challenges presented, that require full power.

That is not to say a single point peak maximum power efficiency drive is not adequate for many. It is typically and an expedient practical solution, the more so if you can oversize the motors power output . However, here limited legally to a small amount of power, multi gearing it enables peak power, to be realised over a much wider speed range, which might be attractive to others.

 

[vfr400]

First of all what I clearly was discussing was efficiency in respect to speed of the motor, and how this impacts on road speeds depending on gearing.
Be very sure I am not “assuming that electric motors are similar in any way to motors that burn say petrol or diesel, especially with regard to torque and RPM.”

So back to what I spoke about, efficiency vs rpm.

The document you referenced, as you said “explains the subject rather well in my opinion” , at least the subject I discussed, as I explain:

Figure 4 of the document shows that the motors, as I expected, have a parabolic efficiency vs rpm curve, indeed a whole nest of varying power curves reflecting the voltage applied, Figure 15. The example given peaking at 60-65% at maximum power.

Note it clearly endorses what I said “Logic has it that any motor efficiency curve must diminish towards its lower revs, as stalled the efficiency has to be zero, power goes in but none comes out.”

Thus that motor in a hub,without any gearing change features, has a unique road speed where it has the potential to yield peak full power efficiency.
On the other hand, that same technology motor if used where multiple ratio gearing options are featured, has the same number of road speeds where the peak full power efficiency is available, as the number of ratios in the gearing.

It is true a single epicycle fixed gear ratio in a hub drive offers the potential for a higher mechanical efficiency than a crank drive and dérailleur set up, so a higher overall power efficiency, but it is confined to being available at just a single road speed .
Whereas, with the crank drive and geared ratios, sometimes as many as 21, then it has 21 peak efficiency points spread across the whole spectrum of road speeds. Offering “better” ability if needed to meet the loading challenges presented, that require full power.

That is not to say a single point peak maximum power efficiency drive is not adequate for many. It is typically and an expedient practical solution, the more so if you can oversize the motors power output . However, here limited legally to a small amount of power, multi gearing it enables peak power, to be realised over a much wider speed range, which might be attractive to others.

That's all true. A hub-motor is most efficient at a certain wheel speed, and a crank motor that is most efficient at a certain crank speed. It's all very well picking out particular characteristics and discussing theory, but the real world brings in all sorts of other factors. The only true way to compare is during actual rides. When that German magazines did their tests up a steep mountain (well documented on several occasions if you search the forum), the hub-motors came out a long way in front of the crank drives. What this means is that there must be other significant factors that caused it and/or this theoretical situation of the crank motor being kept in its optimal range of efficiency doesn't happen in practice..

 

[Samcycles]

I'm sure people coming in to this forum for the first time are bewildered by the way some members hijack their questions to launch another attack in their personal crusade. It's off putting and might well deter them from coming back.

Personally I watched as a guest for a few years and decided best to do my own research rather than ask opinions because some posters here are downright offensive about which drive motor you have chosen.

Why don't those who feel the need just start a post called "Tilting At Windmills" and argue semantics all day long and let the newbies and those of us who really don't care can simply ignore the thread.

PS have a wonderful weekend and enjoy whatever you ride.

 

[joelectric]

I'm sure people coming in to this forum for the first time are bewildered by the way some members hijack their questions to launch another attack in their personal crusade. It's off putting and might well deter them from coming back.

Personally I watched as a guest for a few years and decided best to do my own research rather than ask opinions because some posters here are downright offensive about which drive motor you have chosen.

Why don't those who feel the need just start a post called "Tilting At Windmills" and argue semantics all day long and let the newbies and those of us who really don't care can simply ignore the thread.

PS have a wonderful weekend and enjoy whatever you ride.

I agree, 'it's the single point of failure' of this forum

 

[vfr400]

I'm sure people coming in to this forum for the first time are bewildered by the way some members hijack their questions to launch another attack in their personal crusade. It's off putting and might well deter them from coming back.

Personally I watched as a guest for a few years and decided best to do my own research rather than ask opinions because some posters here are downright offensive about which drive motor you have chosen.

Why don't those who feel the need just start a post called "Tilting At Windmills" and argue semantics all day long and let the newbies and those of us who really don't care can simply ignore the thread.

PS have a wonderful weekend and enjoy whatever you ride.

OP didn't ask a question. He just posted some facts to promote discussion. The whole point of forums is to discuss different ideas. I can understand that bigots, who don't like to hear other people's ideas, wouldn't appreciate that.

 

[Andy-Mat]

I'm sure people coming in to this forum for the first time are bewildered by the way some members hijack their questions to launch another attack in their personal crusade. It's off putting and might well deter them from coming back.

Personally I watched as a guest for a few years and decided best to do my own research rather than ask opinions because some posters here are downright offensive about which drive motor you have chosen.

Why don't those who feel the need just start a post called "Tilting At Windmills" and argue semantics all day long and let the newbies and those of us who really don't care can simply ignore the thread.

PS have a wonderful weekend and enjoy whatever you ride.

Speaking for myself, (but I am far from alone here) I find your own style of post offensive, when you accuse others of the same thing, but without mentioning exactly what was said and by who, or why its offensive!
The its simply "Fake News" the way you do it!
Try sticking to the TRUE facts, and use those TRUE facts to try and help your "case"because with this post of yours, you are helping no one at all, least of all newbies looking for help in selecting maybe a new e-bike.
Place supporting web links here as well, showing that you are at least reading the various news items about e-bikes!
But no, nothing tangible or even remotely helpful.
If you actually read and understood what some professional, testing journalists write about certain models, you would see that the comments by others here, are in fact supported by those same journalists!
Ponder on that for a few hours!
Then get fully informed. You have the whole weekend ahead!
Andy

 

[Andy-Mat]

I agree, 'it's the single point of failure' of this forum

Its apparently the same way Trump tries to run the USA!
Do what I say, not what I do!
Also a single point of failure, as November in the USA will definitely show!
Have a great weekend.
Andy

 

[BazP]

OP didn't ask a question. He just posted some facts to promote discussion. The whole point of forums is to discuss different ideas. I can understand that bigots, who don't like to hear other people's ideas, wouldn't appreciate that.

Intimating that Samcycles may be a bigot exemplifies his views on this forum exactly.

 

[Andy-Mat]

Intimating that Samcycles may be a bigot exemplifies his views on this forum exactly.

Then why is he here?
Surely he has freedom of choice....?

 

[BazP]

Then why is he here?
Surely he has freedom of choice....?

There it is again.

 

[Samcycles]

OP didn't ask a question. He just posted some facts to promote discussion. The whole point of forums is to discuss different ideas. I can understand that bigots, who don't like to hear other people's ideas, wouldn't appreciate that.

Interesting response, you don't know me or anything about me and yet you feel justified to make these comments. I've personally experienced bigotry in all its ugly reality and despise it. FYI this isn't it. I respect everyone's right to their own opinion but I am not obligated to agree with it.
My post was general, aimed at no individual and in relation to tit for tat posts from opposing arguments that have no tangible link to the OP's original post.
Debate is good but there are clearly those on all sides who's opinions are too entrenched to see the other side.

 

[Samcycles]

Then why is he here?
Surely he has freedom of choice....?

I'm here because I choose to be and you are absolutely right I have freedom of choice and freedom of expression too.
You appear to have taken offence at my freedom of expression.
My experience on this forum is that some posts could be offensive to others. I don't need to reference every post as I'm sure you have read them for yourself but the derision of Chinese hub drives as incapable of climbing hills by some and the mocking of those who buy so called "overpriced" German crank drives to give a general example is offensive to those who have spent a lot of their money on a bike , and may now be made to feel stupid by some of these comments.

Speaking for myself, (but I am far from alone here) I find your own style of post offensive, when you accuse others of the same thing, but without mentioning exactly what was said and by who, or why its offensive!
The its simply "Fake News" the way you do it!
Try sticking to the TRUE facts, and use those TRUE facts to try and help your "case"because with this post of yours, you are helping no one at all, least of all newbies looking for help in selecting maybe a new e-bike.
Hardly the poi
Place supporting web links here as well, showing that you are at least reading the various news items about e-bikes!
But no, nothing tangible or even remotely helpful.
If you actually read and understood what some professional, testing journalists write about certain models, you would see that the comments by others here, are in fact supported by those same journalists!
Ponder on that for a few hours!
Then get fully informed. You have the whole weekend ahead!
Andy

 

[vfr400]

Interesting response, you don't know me or anything about me and yet you feel justified to make these comments. I've personally experienced bigotry in all its ugly reality and despise it. FYI this isn't it. I respect everyone's right to their own opinion but I am not obligated to agree with it.
My post was general, aimed at no individual and in relation to tit for tat posts from opposing arguments that have no tangible link to the OP's original post.
Debate is good but there are clearly those on all sides who's opinions are too entrenched to see the other side.

Basically, you were trying to shut down discussion because you didn't like what was being said. I didn't see anybody making attacks or on any personal crusades. Can you show me where that happened?

but the derision of Chinese hub drives as incapable of climbing hills by some and the mocking of those who buy so called "overpriced" German crank drives to give a general example is offensive to those who have spent a lot of their money on a bike , and may now be made to feel stupid by some of these comments.

These guys are entitled to express their opinions. I think you're reading too much into what people write instead of accepting what they write at face value. You're using words like attack, crusade, mock and derision. I can't say that I can see anything that warrants those words.

If you truly didn't want the thread to drift off from what OP started, why did you start this part of the discussion? Making statements like you did was certainly going to provoke responses, or did you think that you're master of the forum and your word would be final? None of it makes sense to me.

 

[vfr400]

Are there Chinese bikes with Chinese kit, let alone the quoted £900 example, that are technically as sophisticated as drives from Bosch, Yamaha, Shimano etc?
By that bikes with drive systems with the algorithms to manage true "power assistance" as opposed to electrically powered bikes where the contribution of the cyclist is not a term in the power management algorithm.
I ask as I don't know, but are we comparing anything like similar products?

Having "tested" early throttle, and cadence managed power controlled cycles, along with true power assisted systems from Bosch, Derby, Yamaha and Shimano, the two groups are totally differing experiences, so not like for like.

The answer to your first question is yes. You can get just about everything from China, though prices generally go up as they become more sophisticated.

A Bafang Maxdrive motor is about £500. Much cheaper, but still with nice torque sensing is the Tongsheng TDZ2 at around £300 for the whole system less battery.

Your experience of early throttle and cadence managed bikes might be a little out of date. Those things have improved a lot in recent years. You should try a modern Wisper or Juicy with torque sensing if that's what you want, though I maintain that torque sensing has little if any advantage for a commuter or touring bike. I personally prefer a cadence sensor system for my type of riding, which is basically just travelling around touring, visiting and shopping, and for that type of riding I wouldn't entertain a crank motor, which I think are just too inconvenient. A well chosen hub-motor can do everything an equivalent crank motor can, and I think the ride is just so much more pleasant. If I want exercise, I use my road bike. If I did proper off-road cycling, I'd want a Bosch CD bike - horses for courses.

I've done the Bosch training so I'd be able to do my own maintenance if I had a Bosch bike, but for those that like fixing things themselves, they're going to be stuck if they have a Bosch Shimano, Brose, etc system. I think this is a significant factor for many people's choice. It can be extremely frustrating seeing your bike stuck in the bike shop for weeks at a time while they try to figure out what to do with it when its gone wrong. Obviously, some shops are better than others, but in my experience good ones are few and far between.

Then there are running costs. I built my bike 6 years ago for £1100. I've done 6500 miles and the total costs have been about £30 for front brake pads, a chain, a chainwheel and a gear cable. If I scrapped the bike tomorrow, it will have cost 17p a mile, but I think I will get many more miles from it yet. An equivalent spec bike with a Bosch motor would have cost over £3000 and probably £100 a year for chain and gear replacements. If anything went wrong in those 6 years, the costs would escalate. Already its three times the cost of what I have.

What I'm trying to say is that there's a lot more to bike choice than whether one type of motor makes your legs feel good, and things are changing all the time, so you need to make sure that your experience is up to date. You did ask, I think that's a good sign.

 

[Bobajob]

I'm sure people coming in to this forum for the first time are bewildered by the way some members hijack their questions to launch another attack in their personal crusade. It's off putting and might well deter them from coming back.

Personally I watched as a guest for a few years and decided best to do my own research rather than ask opinions because some posters here are downright offensive about which drive motor you have chosen.

Why don't those who feel the need just start a post called "Tilting At Windmills" and argue semantics all day long and let the newbies and those of us who really don't care can simply ignore the thread.

PS have a wonderful weekend and enjoy whatever you ride.

ive been on the brunt of one of these forum members attacks which I agree can be tedious.
I find now to just skip 99.999% of what their agenda is and read those with something to contribute.
no doubt as you will be aware there are several very knowledgeable and amicable contributors who’s contribution outweighs the tedious arguments from others.
it takes a while for newbies (which I’ve found from my own experience) to separate those who have valid replies and those with the same boring agenda.

 

[Woosh]

Exactly what is this 'Level of sophistication?'

measure the same thing 1,000 times a second but actually come to the same conclusion.
I don't dismiss the higher sophistication in design and the better stability in performance.
The positioning of the motor has a big impact on how you like your bike, sensing technology is a separate issue. I like both sensing technologies but prefer cadence sensor.
Chinese motors tend to stick to simplicity and manufacturers exaggerate their performance, like maximum torque.
A crank drive kit won't give you the same ideal low parasitic torsion like a crank drive bike.

 

[Quarryjmiller]

Returning to the Bosch ‘get you home’ mode I was under the impression that this was a part of the Bosch three strikes & you are out policy, the first & second time you dongle or mess with it you can limp to a dealer to have the system reset, the third time and the motor has to go back to Bosch.
I find the whole return the motor to Bosch thing frustrating and have commented on this forum in the past about this very subject - my comments weren’t very well received by some forum members, some doubted my integrity.
To be fair to Bosch though, they are undoubtedly under pressure to try and stop their motors being altered and modified to enable riders to circumvent the regulations that restrict eBikes to a maximum 25kmh limit, they and the better known brands in Europe are being scrutinised by the regulation makers at the EU, the French have already imposed new legislation https://cyclingindustry.news/french-government-lead-on-e-bike-tuning-with-threat-of-e30000-fine/ and the Dutch have legislated against Speed Pedelecs from using cycle lanes.

The eBike take up in the UK has exploded, the media are right behind it and it is only a matter of time before the media turns on it because that’s what they do don’t they?

The last thing that I (or Bosch I suspect) want is to end up with eBike access to cycle paths being restricted and for helmets and number plates being made compulsory (the list goes on) because the regulations are being casually disregarded, it’s not as though the 15.5mph cut out stops you going faster you just have to pedal harder, if you cannot or will not pedal harder you have a choice, go slower or buy a speed pedelec.
The only questioning of dongles that I have seen in this thread has consistently referred to warranty implications none to either safety or the ethics of tampering with a bike & concealing it from the company that you expect to foot the bill for any warranty repairs.
The Bosch or hub motor debate reminds me of my two sons when they were much younger - one was a PlayStation fan, the other an Xbox fan, neither had a good word to say about the others choice but that didn’t stop them playing on each other’s machines.
I’ve got a Legio Pro with a generation 3 CX and an EZEGO Commute with a rear hub, both excellent bikes but there is no doubt in my mind that the EZEGO is far more fun than the Legio, as Xavier Hollander once said ‘it’s different strokes for different folks’ so you may feel differently, there is no need for anybody to fall out over it.

 

[sjpt]

and the Dutch have legislated against Speed Pedelecs from using cycle lanes.

Absolutely. And a reminder to those that forget, use of Speed Pedelecs in cycle lanes is illegal in UK too; not (as I understand it) because there is explicit legislation banning it but because there isn't any legislation enabling it. Speed pedelecs just fall under the general 'motor vehicle' category.

 

[Andy-Mat]

I'm here because I choose to be and you are absolutely right I have freedom of choice and freedom of expression too.
You appear to have taken offence at my freedom of expression.
My experience on this forum is that some posts could be offensive to others. I don't need to reference every post as I'm sure you have read them for yourself but the derision of Chinese hub drives as incapable of climbing hills by some and the mocking of those who buy so called "overpriced" German crank drives to give a general example is offensive to those who have spent a lot of their money on a bike , and may now be made to feel stupid by some of these comments.

Think about this, if you are unwilling or unable (please be so kind as to tell us why) to pick out and detail fully/exactly, what you yourself apparently see as offensive here on Pedelec, and show us all clearly (maybe you really DO have a good valid point!), exactly what was the reason for this latest post of yours?
I myself find generalisations to be totally unacceptable, as I am a great believer in the old saying "Put up or **** up!"
So if you cannot describe it for some reason, it also cannot therefore be important enough for you either, or you would be specific!
I am also a person who does believe in the "unvarnished" truth, which some people may find upsetting, as telling the truth is simply not their favourite idea!
But anything LESS than the whole truth, almost always causes extra trouble for absolutely no reason at all.
There are a few here on Pedelec who try to shut down the truth about ANYTHING they do not agree with.
You may have noticed, on many things that I take seriously, I usually supply supporting web links.
It appears that few others feel the need for that, which makes their "arguments" look at best "made up!"
I sincerely wish you and everyone else on Pedelec to have a really great weekend, I am!
Andy