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by CJ
28 Sep 2022, 5:12pm
Forum: Electrically assisted pedal cycles
Topic: Is 250w enough power for modest speed up steep hills
Replies: 359
Views: 48166

Re: Is 250w enough power for modest speed up steep hills

Vantage wrote: 28 Sep 2022, 2:56pm I seem to remember a case a number of years ago in the TDF where a bike check (I think) found the bike to have a battery installed within the seat tube powering a small motor within the bottom bracket. Not very powerful, but enough to give the rider an edge.
Off topic, but I think you'll find that most if not all bikes in the TDF have a battery installed within the seat-tube (or elsewhere) powering two small motors (or servos) within the gear mechanisms. Not very powerful, but enough to give the rider an edge.

To suggest that this borrowed energy does not give an edge is nonsensical. Nothing new goes onto a racing bike that does not in someway help the rider perfom better than before. So I don't think any stored energy device should be allowed by UCI - not unless the energy is topped up by the rider during the event.

This could very easily be done with existing technology. And if that small generator were to cause sufficient drag that no competitor wanted such improvements as electric shifting, power meters, race radios... then we would know for sure that all recent winners really were cheating!
by CJ
26 Sep 2022, 6:46pm
Forum: Electrically assisted pedal cycles
Topic: Is 250w enough power for modest speed up steep hills
Replies: 359
Views: 48166

Re: Is 250w enough power for modest speed up steep hills

Jdsk wrote: 25 Sep 2022, 6:28pm The Wikipedia article says that the UK has a weight limit of 30 kg, but the GOV.UK overview doesn't.
https://en.wikipedia.org/wiki/Electric_ ... gal_status
https://www.gov.uk/electric-bike-rules

Is there a current (!) limit?
I think the wikipedia article may be confusing the 1983 UK regulation on EAPCs, that did have a weight limit but now applies only to such pre-existing e-bikes as remain in use, with the BS/EU Standard, that applies to all EAPCs first used since (a certain cut-off date I don't recall) and does NOT stipulate any weight limit.
by CJ
25 Sep 2022, 1:14pm
Forum: Electrically assisted pedal cycles
Topic: Is 250w enough power for modest speed up steep hills
Replies: 359
Views: 48166

Re: Is 250w enough power for modest speed up steep hills

tenbikes wrote: 22 Sep 2022, 8:21pm ^^^ I have no idea of the weight but it is much more than I can lift......logs and wood chippings, loaded in small units to two massive panniers and a trailer.

Off road. Very steep. Distances up to 2km.

Mid drive. 34 front, 46 rear.

Personally I have no issue with power, it is speed that seems to be the issue for people.

It is clear from this thread that policing power output is next to impossible: you need an electronics lab to measure the motor.
Police cannot do this on the beat.
They can check maximum assist speed though, and put a speed gun on bikes which appear to be going excessive speeds.
Sure, we know that that is unlikely too but it is more attainable as a control measure that wattage.

If a bike at 250w passes you at 30mph and one passes you at 15mph but with a wattage of 500w, what will you notice? Speed or power? Which of the two would you prefer to experience?

Cargo bikes like mine should have a generous power allowance but still be speed restricted in the same way as a fast/light road ebike.
I disagree. Once you have more electrical power than typical human power, the machine ceases to be an electrically assisted pedal cycle, and becomes a pedal assisted motor cycle. We already have a word for that: moped.

There is a good argument for a new light touch regulation of speed-limited lightweight electric mopeds, such as the speed pedelecs that are popular in continental Europe, but not here because UK regulates mopeds so strictly that one might as well get a full-blown motorbike. But that is not an argument for this forum. That is for the motorcycling lobby.

I think that cargo e-bikes - including tenbikes' log hauler - should come under the same regulatory regime as this new category of vehicle. They are a significantly heavier vehicle than even a loaded touring bike. Normal bicycle tyres and brakes are not really up to the job and someone in control of that much mass on any kind of downslope has a literally much heavier responsibility for the safety of others - regardless of what motor-assist speed they may be permitted. With greater power comes greater responsibitity, so licensing and resistration seems entirely appropriate: for any heavier and/or more powerful vehicle even if the motor is limited to 25kmph. However I think that it would be sensible to let 25kmph-limited cargo cycles into pedestrianised shopping streets 24/7, along with bicycles, and not just during specified delivery hours. So I think there's some merit in maintaining a distinction between speed-pedelecs and those that are also more powerful but not also faster.
by CJ
22 Sep 2022, 3:17pm
Forum: Electrically assisted pedal cycles
Topic: Is 250w enough power for modest speed up steep hills
Replies: 359
Views: 48166

Re: Is 250w enough power for modest speed up steep hills

Cugel wrote: 22 Sep 2022, 10:59amI would argue that there's a better way to govern the limitations allowed to e-bikes to prevent them from becoming electric motorbikes whilst providing assistance to those weaker cyclists who would benefit from more power.

Use the BB strain gauges to limit the total motor + rider wattage output to a maximum figure equivalent to the power output of an average fit cyclist - say 250 or, at most, 300 watts. No speed limitation on motor assistance.
Yes, that would be a better way, but its implementation would be a whole lot more complicated than BB strain gauges, which wouldn't work for hub motors.

I also think that a speed limit on motor assistance would still be desirable. Reason: to limit reckless speeding around slower users of shared facilities. When I say that, I do NOT suppose that e-bike riders are any more reckless by nature than riders of regular bicycles. But whereas a reckless e-biker has to do nothing more onerous than select 'turbo' mode whilst 'ghost pedalling', a reckless rider using just his own legs has to work a bit harder. Maybe not a whole lot harder, but it's still more effort, and it goes against human nature to waste one's own effort. So in places where there's a high probability of having to use the 'energy wasters' (brakes) to slow down again, one simply doesn't bother!

Laziness, if you like to call it that, inhibits the reckless leg-biker, but the reckless e-biker not-so-much! That's why I think the 'e' needs a speed limit - at about the point where speed begins to exceed that of a runner and where the extra effort of pedalling faster begins to ramp up.
by CJ
22 Sep 2022, 2:39pm
Forum: Electrically assisted pedal cycles
Topic: Is 250w enough power for modest speed up steep hills
Replies: 359
Views: 48166

Re: Is 250w enough power for modest speed up steep hills

PH wrote: 22 Sep 2022, 11:08am
Cugel wrote: 22 Sep 2022, 10:59am The main purpose of an e-bike is to make less fit cyclists abe to ride like more fit cyclists. At present, this is only possible up to 25kph. Why the speed limit? Surely only a power limit is needed to prevent e-bikes becoming e-motorbikes?
Please stop thinking as a cyclist. Fit, unfit, need... it's all irrelevant if you start thinking of the users as people. Your main purpose may well be right for yourself, stop assuming it's right for me, or anyone else.
AFAICT from lurking on the E-bikes UK facebook forum, most of the greed for speed comes from people who don't think of themselves as 'cyclists' - whatever that may mean!
Vantage wrote: 22 Sep 2022, 2:04pm Lots of people ride bikes but don't consider themselves cyclists. For them the bike, powered or not is just a means of travel.
Indeed, and I think that's a very sad consequence of how the anti-cycling tendency in anglophone culture has made 'cyclists' into an outgroup.

So please, let's have no more of this arbitrary division into cyclists versus people on bikes. It's a nonsense. In fact there are host of different motivations behind the act of riding a bicycle and as many different ways of being a cyclist as you can shake a stick at.
by CJ
22 Sep 2022, 2:13pm
Forum: Electrically assisted pedal cycles
Topic: Is 250w enough power for modest speed up steep hills
Replies: 359
Views: 48166

Re: Is 250w enough power for modest speed up steep hills

tenbikes wrote: 22 Sep 2022, 11:38am Indeed.
My current e bike is for hauling loads off road. It needs to be more than 250w, but speed is irrelevant, in fact I have limited it down to 10mph because that's all I can manage safely off road with a load.
It sometimes gets defeated even with its generous power rating.

Think tractor v sports car. I have no need or interest in a sports car.
If speed is irrelevant, it doesn't need more than 250W, it just needs a lower gear. But perhaps it's a hub-motor, without any possibility of altering the relationship between motor rpm and wheel rpm. In that case you've got the wrong kind of motorisation for the job, because hub-motor systems are invariably optimised to operate most efficiently at a speed just below their top limit. They'll also drive the bike along at lower speeds, and produce more torque at those lower speeds, which is what you want to get up the hill that's making the bike slow down. When the motor turns more slowly however, it becomes less efficient. That means more of your precious battery power goes into heating rather than turning the motor! And sooner or later the controller kicks in, to limit the current and stop the motor getting too hot. After this point the torque increases less than the motor slows, so if the gradient steepens further the bike slows down a lot more - and ultimately stops. At the point when it stalls it's outputing zero watts and long before that happens it'll be down below 250W, regardless of how powerful it claims to be when going faster!

Gears, if used intelligently, allow the motor to keep spinning at close to its most efficient rpm as the bike slows down. Gear down low enough and you'll still be getting the full 250W, whilst slowly climbing those hills that defeated your sometimes more powerful motor.
by CJ
21 Sep 2022, 2:27pm
Forum: Electrically assisted pedal cycles
Topic: Bafang feeble walk mode. Fix??
Replies: 10
Views: 2067

Re: Bafang feeble walk mode. Fix??

tenbikes wrote: 20 Aug 2022, 10:33am My walk mode uses a long push on the PAS controller ( the minus button) then it is hands free. This is helpful off road as I can wrestle with the bike using both hands .
Sounds like you may be using walk mode whilst sitting on the bike, rather than walking beside it. That may explain why you find it rather feeble!
by CJ
21 Sep 2022, 2:04pm
Forum: Electrically assisted pedal cycles
Topic: Lightweight electric bike
Replies: 53
Views: 14872

Re: Lightweight electric bike

Cugel wrote: 28 Aug 2022, 6:16pm I believe that the best value e-bike capable of most of what you want is this:
https://www.wiggle.co.uk/vitus-e-substa ... 105-2022-1

There is an identical frame set up as a gravel bike, with wide tyres and a single chainring. But if you want a touring bike, the road version is a better choice.
Why is that? The gravel version has a substantially lower bottom gear, so will be more capable of hauling luggage up steep gradients. The wider tyres will also better protect the wheels from damage on imperfect surfaces - and as they come on 650B wheels, in the same frame, you have scope to fit a slightly slimmer tyre in the event that mudguard clearance is less generous than you want.
by CJ
21 Sep 2022, 1:22pm
Forum: Electrically assisted pedal cycles
Topic: This may be a first prosecution of an illegal ebike.
Replies: 54
Views: 21385

Re: This may be a first prosecution of an illegal ebike.

hemo wrote: 20 Sep 2022, 4:55pm At the end of the day the rating is what ever the manufacturer puts on the motor and as Cugel says for sure 250w or 350w labelling is the same motor, not sure about 500w but wouldn't surprise me the motor being the same if the voltage is the same. A 350w labelled one being the same as 250w laballed one, the only difference making it illegal is the labelling.
It'll be the same motor, but a different battery voltage. The fact is a DC motor can be operated at a range of different voltages and will have a different output characteristic at each voltage. And at any voltage, the power output varies depending upon the speed at which the motor spins and how much current the controller allows it to draw. So the manufacturer's labelling has to consider not just the motor, but the system as a whole: motor, battery and controller. The continuous rated power will be measured when the motor is running at or close to peak efficiency. Demanding more torque, eg by going uphill, slows down the motor and causes it to draw more current. Power = torque × rpm (×PI/30) and in those conditions it is likely that torque will increase more than speed reduces, so that a bit more than the rated 250W is output. Whatever: the increased current at constant voltage greatly increases electrical power consumption, hence the drop in efficiency.

Electrical input is a simple thing to meter, so that's what e-bike tinkerers and internet bloggers do. Most of the tinkerers are after more power and speed and some of them have an agenda to subvert the EU rules on e-bikes. They seize upon these sometimes large, transitory power inputs and use them to spread confusion by allegations that EU-approved e-bikes regularly and greatly exceed their 250W rating. Figures as high as 800W are bandied about. Figures that high are probably mere speculation, but it's not unlikely that some approved systems could occasionally draw as much as 500W whilst still outputting only 250W - or perhaps a little more, as may be permitted by the way the regulations are written. The difference goes into heat of course, which the system may nevertheless be able to withstand - at least for a while.

Mechanical energy is far more difficult to measure than electricity, but that's what matters when it comes to the performance of the bicycle. We measure the performance of a human cyclist after all, by how many watts they can produce at the pedals, not the number of calories they must consume in order to do that!
by CJ
20 Sep 2022, 6:21pm
Forum: Touring & Expedition
Topic: European trains - sleeper service
Replies: 191
Views: 35467

Re: New European Sleeper Timetable.

simonhill wrote: 18 Sep 2022, 1:11pm Note I did say scheduled.
My apologies for continuing this off-topic discussion, but it seems to me that the old distinction between scheduled and charter flights has lost its meaning. Nowadays every carrier is competing on cost, with EasyJet and RyanAir publishing comparable "schedules" of flights to those of BA and Lufthansa.
by CJ
18 Sep 2022, 12:47pm
Forum: Touring & Expedition
Topic: European trains - sleeper service
Replies: 191
Views: 35467

Re: New European Sleeper Timetable.

simonhill wrote: 23 Dec 2021, 10:54am Lufthansa were (in)famous for being one of the few scheduled European airlines that charged for bikes.
That's not very fair to bring up nowadays, since most airlines have been charging for bikes for years - and charging so much that one may easily pay less for a seat!
by CJ
18 Sep 2022, 10:22am
Forum: Bikes & Bits – Technical section
Topic: I hate disc brakes - help!
Replies: 108
Views: 12505

Re: I hate disc brakes - help!

Cugel wrote: 30 Aug 2022, 1:42pm ... after using a pair of the hybrids for some time, I got tired of having to constantly re-do the cables to get them back to their initial performance. Full hydraulics replaced them and are fit & forget (the hoses and their fluid, at least).
It doesn't have to be like that. I fitted TRP Hy-Road (hybrid cable-hydraulics) on my most-used bike when I built it up three years ago and haven't needed to adjust either the brakes or the cables at any time - even when changing pads. And that's in spite of being too impatient to build the bike to wait for the special compressionless casing the instructions told me to use! I may get around to that eventually, when I need to re-tape the handlebars, but the brakes work very well nevertheless with regular spiral coiled casing all the way from lever to caliper. I can brake with one finger and lock the wheel if necessary, which I know since I did once instinctively pull a stoppie to avoid a low-speed collision.
by CJ
18 Sep 2022, 9:53am
Forum: Touring & Expedition
Topic: When will Eurostar recommence carrying bikes?
Replies: 202
Views: 35117

Re: When will Eurostar recommence carrying bikes?

MelW wrote: 13 Sep 2022, 10:55pm If you have a folding bike eg Brompton then there is no problem taking it on the Eurostar, TGV or indeed any train?
If you have a very compact folding bike, just like a Brompton, and a bag for it, then no problem. And whilst I have done a bit of touring with a Brompton, it was a very different kind of tour: indeed more with a bike than on it.
by CJ
17 Sep 2022, 7:02pm
Forum: Electrically assisted pedal cycles
Topic: Is 250w enough power for modest speed up steep hills
Replies: 359
Views: 48166

Re: Is 250w enough power for modest speed up steep hills

Nearholmer wrote: 17 Sep 2022, 4:21pm
the bike behaved the same way with a throttle, why should anyone else be concerned if I was pedalling or not?
TBH, I’m personally not.
Me too. I was very happy with the 1983 UK E-bike legislation, that allowed 200W of assistance up to 15mph, with or without pedalling. We had that for ten or more years before the EU started writing their standard and I argued in committee that it didn't matter if e-bikes had throttles: British experience proved that power and speed limits alone were enough to stop anything like a motorbike masquerading as pedal cycle. I also pointed out that no power without pedalling, especially if that power were delivered in proportion to pedalling effort, ensured that those who most needed assistance, got the least, or in case of extreme need - none at all!

I have always been worried that putting too much emphasis on pedalling would lead to those who want a yard when you give 'em an inch, to argue that any amount of power and speed is still just like cycling because look: you still have to pedal! I made that argument too, and look, we now have the speed pedelec, clearly some kind of moped, but pretending it's still a bit like a bicycle because you have to pedal it to turn the motor on. How ridiculous it that?

So yeah, throttles are okay by me. But on the CEN committee I was in a minority of one.
by CJ
17 Sep 2022, 6:37pm
Forum: Electrically assisted pedal cycles
Topic: Is 250w enough power for modest speed up steep hills
Replies: 359
Views: 48166

Re: Is 250w enough power for modest speed up steep hills

Bonzo Banana wrote: 17 Sep 2022, 8:54am The EU legislation is a mess and is not used in most of the world where their legislation is far superior... We desperately need to get away from this dire EU legislation and return to standards similar to being used elsewhere in the world.
By most of the world you presumably mean USA - a country that has totally lost the plot when it comes to everyday cycling, where the cycling conversation is dominated by cycle sport, resulting in lax e-bike regulations that let people pretend that a 750W machine doing 20mph is just like a pedal cycle. It isn't of course, with the result that e-bikes are getting banned from the few places where one can ride without traffic in that unhappy country.
I've seen so many conversations on forums about how hated the EU legislation is
Of course it's hated, by those who want to speed and have the fun of punchy accelleration like a motorbike, without the hassle of registration, insurance and a motorcycle helmet. Tough. If you manage to get US-style regulation here, you'll lose the goodwill of the pedal cycling community. You will no longer be welcome amongst us and we will campaign to have you excluded from the few places and priviledges afforded to cyclists in this country. You can ALL then go play with the motorcyclists.
Across the EU throttle based ebike kits still sell in huge numbers and the police in many countries simply ignore the legislation because its just garbage. Forcing a pedelec system on people is utterly moronic it discriminates against the weak, disabled and elderly. I would be embarrassed to admit any connection to this dire legislation.
On the contrary, in that video by an American visiting Europe that you posted a link to above, he says how Europe is a huge market for ebikes, where they're nearly all EU style e-bikes. Sure there must be some illegal bikes, but they are a tiny minority and Europe satisfies the e-mopedists with its speed pedelec class. Admittedly that hasn't caught on in UK but that's because UK has a downer on mopeds. I don't know the details because I'm not into motorcycles but it is evident that something happened to the UK legislation in the seventies that made mopeds all but disappear from our streets, whereas they remained popular in the rest of Europe. If you want speed pedelecs to be available and more easily usable here, I suggest you go talk to the motorcyclists, whose proper business it is to sort that out.
As for Bosch peak wattage you see it everywhere in forums in comments for those who can measure current draw. A thread here shows the Chinese mid-drive motors aren't peaking as high as Bosch perhaps 200W difference and consequently they don't quite match Bosch Nm output. Here there is a claim of 850W for a Bosch motor but I'd say its more common to see around 800W or just under 800W as stated maximum power. The current draw has been measured on a Bosch battery and for a reasonably prolonged period for something like 600W. This has been widely discussed on many ebike forums. Most of the information about ebike motor current consumption is forums because most commercial information is inline with what the the motor manufacturers want to present with regard their fake 250W rating.
I thought so, you are indeed confusing electrical power input with mechanical power output.

Measuring the power of e-bikes by how much electricity they consume, makes as much sense as measuring the performance of racing cyclists by how much food they eat!

There will be some kind of relationship, but it's rather tenuous because each case depends critically upon how efficiently a different source of energy is converted to mechanical work, rather than being wasted in heat. And when it comes to ensuring that an e-bike moves something like a pedal cycle, what matters is how power is delivered to the wheels.