Ribble SLE

Electrically assisted bikes, trikes, etc.
peterb
Posts: 33
Joined: 2 Dec 2017, 10:13am

Re: Ribble SLE

Postby peterb » 2 Mar 2019, 3:14pm

horizon wrote:
peterb wrote: that equates to a safe range of 75 km or so, on average terrain - undulating with one or two short hilly stretches. I am 62kg, and the bike fully equipped around 16kg. Worth pointing out that the more you ride above the assistance cut off of 25kph, the more range you'll get, but in practical terms I consider my maximum range is around 45 - 47 miles.


peterb: what do you find the bike gives you? At the weights you give and the terrain, would not 45 miles be fairly OK? I'm just wondering because I might have thought that higher speed was the bonus but this cuts out at 15 mph so is average speed noticeably higher? I am assuming of course that you have a good level of fitness (indicated by your weight?) and no disability.


- yes, to be safe I operate on a 45 mile maximum. I was with a group this morning on a club ride who were pushing the speed up to 18 mph on the flat and up gentle inclines. Staying with them had a noticeable (edit) positive, lowering effect on the power consumption, increasing range to 10km/10% of charge. I'm not that fit in that I have developed peripheral arterial disease - narrowed arteries in my groin and both legs, which restricts the blood supply to my calf muscles in particular, (hence the ebike) so keeping a 16kg bike moving at 18mph hurts a bit! But I can catch the group as soon as the road goes up hill, however. (Actually they are a good bunch and wouldn't leave me behind anyway!)

Roger_H
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Re: Ribble SLE

Postby Roger_H » 2 Mar 2019, 7:03pm

peterb wrote:The Ribble SLe, Orbea Gain, Pinarello Dyodo and the Wilier Cento 1 all use the same ebikemotion X35 system, the bike model weights differ, Ribble claiming the lightest build. In my experience riding an alloy framed Tiagra equipped Gain I am getting around 8km per 10% of charge, so allowing that I don't want to exhaust the battery completely, that equates to a safe range of 75 km or so, on average terrain - undulating with one or two short hilly stretches. I am 62kg, and the bike fully equipped around 16kg. Worth pointing out that the more you ride above the assistance cut off of 25kph, the more range you'll get, but in practical terms I consider my maximum range is around 45 - 47 miles.

Thanks - to try and put into context what level of power assist would you use to get that range. And say you rode the 45-50 miles on a bike w/o power assist, how long do you think it would take you?

(I ask the latter Q because of suggestions that the average rider turns out 250W in some posts. Now in my racing days - many years ago - my sustained power out put would have been higher - but I suspect 250W would return a lot of riders a 50 mile time between 2 hours and 2 hours 10, if not using pointy helmets etc.

A lot of us are now a lot lower on power output, which is why we are considering e-bikes. I noticed for example the Ribble have signed Sean Yates as a brand ambassador. Now I'm not so stupid as to let this influence me, but Yates is a good example - someone who likes to ride his bike but, for medical reasons, probably now has a power output more in the 100W range.

Roger_H
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Joined: 21 Mar 2018, 12:00pm

Re: Ribble SLE

Postby Roger_H » 2 Mar 2019, 7:16pm

Cugel wrote:
kwackers wrote:
horizon wrote:Thanks for that kwackers (though I'm still getting my head round it!).

I'm looking now at power to weight ratio. This seems to say that a fit cyclist putting out 250W and weighing say 65 kg has a PtoW ratio of about 3.5. Add the bike (say 12 kg) and it's about 3.2. Taking the TV example, an unfit rider of say 95 kg putting out 120W will have a PtoW ratio of 1.2 but less if the extra weight of the bike (24 kg) is added, let's say .9.

However the motor adds back in 250W giving a PtoW ratio of about 3.6. All these figures are very approximate but it seems to me that losing 20 kg of body weight, 10 kg of bike weight and going from 120W to 250W personal power output would neutralise the help of the motor. I think that's a tall order for an individual to achieve but it seems to imply that for most reasonably fit, not overweight cyclists with a lightish bike, they are better off than an overweight, unfit person on a heavy ebike.

NB This post my get the award of the most unscientific piece ever posted on this forum. :D


250w / (65kg + 12kg) = 3.25
(120w + 250w) / (95kg + 22kg) = 3.16

Not much in it, but that's mainly acceleration that's affected.

Then is 250w a good representation of an average cyclist? Might it be less?
What about 95kg, being unfit doesn't necessarily mean overweight.

I think the numbers are interesting but the real point is that if you're a 95Kg person who's unfit and trying to ride a bike the difference the motor makes will be amazing...


I can't speak for the Ribble but can tell you that it's not so simple with a Focus Parlane2 or any of the other e-bikes employing the same motor system (a Fazua Evation).

The motor & battery is rated as capable of a 250W constant output, with a capability to deliver 400W momentarily. In practice, the system detects the pedaling effort of the rider (via strain gauges in the BB gearbox to which the motor drive attaches) and provides a power output calculated to match the rider output in some way.

The obscure part is the "in some way". If one rides the Parlane, it becomes obvious that the motor varies it's output for each of it's three settings (green, blue, red giving: up to 125 watts; up to 250 watts; up to 400 watts, respectively). Going by the (guessed at) amount of power I might put through the pedals of this e-bike when I have a ride on it, there is only the maximums of 125, 250 or 400 watts if I too am putting out something like those wattages in addition, myself.

In practice, if one just tootles along, the motor does the same. I would guess that my output of, what for me is an easy, 150wats the motor in green mode (max 125 watts) is putting out maybe 80 watts. Ditto the blue: my 150 watts might be helped by about 120 watts of motor. And so forth. If I try very hard, so does the motor - accelerating up a significant hill to 15.5mph (motor cut-out speed) is quite rapid when one stomps on the pedals in blue mode.

So, some e-bikes don't have simple set power additions but, rather, variable additions governed by the user's efforts and perhaps also by the bike's speed. (The motor is connected to a speed sensor reading a rear wheel magnet, as well as to the gearbox strain gauges). I'd love to see the profiles used by the motor software for determining what power the motor will give for the rider's speed and pedaling effort.

Does the Ribble work like this? Perhaps, as the idea is that the rider of such sporty bikes should have to still try hard to cycle anywhere they go - they just go faster up the hills and into the wind. .... until 15.5mph is reached and surpassed.

Cugel


Thanks, That's a really interesting set of observation. I had always understood from the various manufacturer's ads that as soon as you touched the pedals, you'd be whisked up to 25kph. But it sounds like no so - rather it sounds like you could pootle along at, say, 12mph and on green the bike wouldn't really make an effort to make you faster?

Do you think all the e road bikes have a similar set up?

peterb
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Joined: 2 Dec 2017, 10:13am

Re: Ribble SLE

Postby peterb » 2 Mar 2019, 7:58pm

Roger_H wrote:
peterb wrote:The Ribble SLe, Orbea Gain, Pinarello Dyodo and the Wilier Cento 1 all use the same ebikemotion X35 system, the bike model weights differ, Ribble claiming the lightest build. In my experience riding an alloy framed Tiagra equipped Gain I am getting around 8km per 10% of charge, so allowing that I don't want to exhaust the battery completely, that equates to a safe range of 75 km or so, on average terrain - undulating with one or two short hilly stretches. I am 62kg, and the bike fully equipped around 16kg. Worth pointing out that the more you ride above the assistance cut off of 25kph, the more range you'll get, but in practical terms I consider my maximum range is around 45 - 47 miles.

Thanks - to try and put into context what level of power assist would you use to get that range. And say you rode the 45-50 miles on a bike w/o power assist, how long do you think it would take you?

(I ask the latter Q because of suggestions that the average rider turns out 250W in some posts. Now in my racing days - many years ago - my sustained power out put would have been higher - but I suspect 250W would return a lot of riders a 50 mile time between 2 hours and 2 hours 10, if not using pointy helmets etc.

A lot of us are now a lot lower on power output, which is why we are considering e-bikes. I noticed for example the Ribble have signed Sean Yates as a brand ambassador. Now I'm not so stupid as to let this influence me, but Yates is a good example - someone who likes to ride his bike but, for medical reasons, probably now has a power output more in the 100W range.


- I can't really answer your question as now I am unable to ride more than 2 - 3 miles on a conventional bike before calf pain forces me to stop. In my late 60s, before leg issues effectively curtailed self propelled cycling, 45-50 miles would have taken a leisurely 4 hrs or so.

kwackers
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Re: Ribble SLE

Postby kwackers » 2 Mar 2019, 8:21pm

Roger_H wrote:Do you think all the e road bikes have a similar set up?

Mine doesn't it's all cadence based.

On level one the max cadence is about 45 rpm, on two about 50 rpm and on 5 about 100rmp (just guessing at the numbers).
The motor starts to reduce power as you approach that cadence.

So pootling around on L1 simply means pedalling lazily, if you pedal faster then there's no input from the motor.
Still get a nice push off the start though.
Levels 3 & 4 have cadences that are similar to my normal riding so I'm just on the edge of what's comfy and I'm adding useful power to the bike whilst getting a useful amount of assist.

(There's also speed based limits, which are lower for the lower powers and higher for the higher ones).

It sounds a bit odd, and indeed it originally felt odd but after about 10 mins I'd gotten used to it. Now it's just second nature.

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horizon
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Re: Ribble SLE

Postby horizon » 2 Mar 2019, 8:43pm

Roger_H wrote:(I ask the latter Q because of suggestions that the average rider turns out 250W in some posts. Now in my racing days - many years ago - my sustained power out put would have been higher - but I suspect 250W would return a lot of riders a 50 mile time between 2 hours and 2 hours 10, if not using pointy helmets etc.

A lot of us are now a lot lower on power output, which is why we are considering e-bikes . . . but Yates is a good example - someone who likes to ride his bike but, for medical reasons, probably now has a power output more in the 100W range.


My interest in this thread was prompted by MrsH saying that she would like to try an ebike. We even have what I think is an excellent recipient bike for a front wheel kit. However, I find it hard to grasp what she might gain that she wouldn't from some sustained build-up of fitness. Even round here in hilly Cornwall, the hills aren't impossible and the fitness gain even greater. As her power-to-weight ratio improved, I reckon the hills would start to disappear; she isn't overweight (60 kg) and has no physical impediment but if you don't cycle regularly in Cornwall it's easy for the gradients to start to loom larger. I am beginning to think it is (a) a mental thing (b) a fear/dislike of the discomfort of going through the building up of fitness and (c) a lack of belief that it is actually possible to be that fit. An ebike therefore would be like a security blanket (for an otherwise fit/healthy person). By the way, I am not talking about regular long commuting here in which an ebike plays a different role.

I would love to be able to measure her power output (and mine) and see just how far off she is from needed any e-assist.
Let's just get Brexit done so that we can get on with the important job of re-joining the EU!

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Cugel
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Re: Ribble SLE

Postby Cugel » 2 Mar 2019, 10:30pm

kwackers wrote:
Roger_H wrote:Do you think all the e road bikes have a similar set up?

Mine doesn't it's all cadence based.

On level one the max cadence is about 45 rpm, on two about 50 rpm and on 5 about 100rmp (just guessing at the numbers).
The motor starts to reduce power as you approach that cadence.

So pootling around on L1 simply means pedalling lazily, if you pedal faster then there's no input from the motor.
Still get a nice push off the start though.
Levels 3 & 4 have cadences that are similar to my normal riding so I'm just on the edge of what's comfy and I'm adding useful power to the bike whilst getting a useful amount of assist.

(There's also speed based limits, which are lower for the lower powers and higher for the higher ones).

It sounds a bit odd, and indeed it originally felt odd but after about 10 mins I'd gotten used to it. Now it's just second nature.


That's interesting. It seems, then, that there are various schemes implemented in different e-bike motor-controller software.

I had a hunt about after the last post about the Focus Parlane2 and found a user-downloadable software thing from Fazua that reports details of various kinds on the motor's behavior during a ride. It isn't clear, yet, how one obtains this data to populate such a report, though. I'll keep looking. I wonder if the LBS software interface, also available from Fazua, would allow tweaks to the power output profiles given in response to the controller setting, strain gauge measurements and wheel speed?

In passing, I also noticed a German manufacturer selling a cheater box for the Fazua, which one attaches in place of the rear wheel magnet sensor. This magic box then lies about the wheel revs, reducing the rev count reported to the motor software so that the motor will continue to work up to 20mph instead of cutting ut at 15.5mph. They want 150 euros for it, the rascals!

Personally I think the 15-5mph cut-off is fine - although something clever that could keep giving motor power up to 20mph but at a decreasing rate might be useful to club riders needing to keep up because their own wattage is compromised.

Cugel

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Cugel
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Re: Ribble SLE

Postby Cugel » 2 Mar 2019, 10:41pm

Roger_H wrote:
Cugel wrote:
kwackers wrote:
250w / (65kg + 12kg) = 3.25
(120w + 250w) / (95kg + 22kg) = 3.16

Not much in it, but that's mainly acceleration that's affected.

Then is 250w a good representation of an average cyclist? Might it be less?
What about 95kg, being unfit doesn't necessarily mean overweight.

I think the numbers are interesting but the real point is that if you're a 95Kg person who's unfit and trying to ride a bike the difference the motor makes will be amazing...


I can't speak for the Ribble but can tell you that it's not so simple with a Focus Parlane2 or any of the other e-bikes employing the same motor system (a Fazua Evation).

The motor & battery is rated as capable of a 250W constant output, with a capability to deliver 400W momentarily. In practice, the system detects the pedaling effort of the rider (via strain gauges in the BB gearbox to which the motor drive attaches) and provides a power output calculated to match the rider output in some way.

The obscure part is the "in some way". If one rides the Parlane, it becomes obvious that the motor varies it's output for each of it's three settings (green, blue, red giving: up to 125 watts; up to 250 watts; up to 400 watts, respectively). Going by the (guessed at) amount of power I might put through the pedals of this e-bike when I have a ride on it, there is only the maximums of 125, 250 or 400 watts if I too am putting out something like those wattages in addition, myself.

In practice, if one just tootles along, the motor does the same. I would guess that my output of, what for me is an easy, 150wats the motor in green mode (max 125 watts) is putting out maybe 80 watts. Ditto the blue: my 150 watts might be helped by about 120 watts of motor. And so forth. If I try very hard, so does the motor - accelerating up a significant hill to 15.5mph (motor cut-out speed) is quite rapid when one stomps on the pedals in blue mode.

So, some e-bikes don't have simple set power additions but, rather, variable additions governed by the user's efforts and perhaps also by the bike's speed. (The motor is connected to a speed sensor reading a rear wheel magnet, as well as to the gearbox strain gauges). I'd love to see the profiles used by the motor software for determining what power the motor will give for the rider's speed and pedaling effort.

Does the Ribble work like this? Perhaps, as the idea is that the rider of such sporty bikes should have to still try hard to cycle anywhere they go - they just go faster up the hills and into the wind. .... until 15.5mph is reached and surpassed.

Cugel


Thanks, That's a really interesting set of observation. I had always understood from the various manufacturer's ads that as soon as you touched the pedals, you'd be whisked up to 25kph. But it sounds like no so - rather it sounds like you could pootle along at, say, 12mph and on green the bike wouldn't really make an effort to make you faster?

Do you think all the e road bikes have a similar set up?


I don't know - but it looks like the motor's output can be profiled to respond to various measurements such as road speed, pedaling effort/rate and the controller setting supplying various levels of assistance.

Some e-bike systems do offer user interfaces or apps to both read and alter these profiles. They generally seem to need a bluetooth-enabled smart phone - although some of the bigger motors might have a fancy controller interface supplied to mount on the handlebars. Others don't have such a sophisticated reporter/controller but promise to do so in the future; presumably just a matter of writing the software as all these e-bike motors and gearboxes seem to have some form of electronic control of their behaviours.

Personally I'd prefer to keep it simple, just accepting the de facto power profiles already set and using the button to select a little , some more or full power mode. The ladywife's Parlane2 is like that at the moment and she enjoys it as it feels just like an ordinary bike .... except your legs are somehow stronger; or (in pink mode) very strong.

If you didn't know it had a motor and someone was controlling the motor power levels remotely, you might just think that the bike was a very good 'un and you were having a good day!

Cugel

thelawnet
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Re: Ribble SLE

Postby thelawnet » 3 Mar 2019, 1:32am

horizon wrote:
Roger_H wrote:(I ask the latter Q because of suggestions that the average rider turns out 250W in some posts. Now in my racing days - many years ago - my sustained power out put would have been higher - but I suspect 250W would return a lot of riders a 50 mile time between 2 hours and 2 hours 10, if not using pointy helmets etc.

A lot of us are now a lot lower on power output, which is why we are considering e-bikes . . . but Yates is a good example - someone who likes to ride his bike but, for medical reasons, probably now has a power output more in the 100W range.


My interest in this thread was prompted by MrsH saying that she would like to try an ebike. We even have what I think is an excellent recipient bike for a front wheel kit. However, I find it hard to grasp what she might gain that she wouldn't from some sustained build-up of fitness. Even round here in hilly Cornwall, the hills aren't impossible and the fitness gain even greater. As her power-to-weight ratio improved, I reckon the hills would start to disappear; she isn't overweight (60 kg) and has no physical impediment but if you don't cycle regularly in Cornwall it's easy for the gradients to start to loom larger. I am beginning to think it is (a) a mental thing (b) a fear/dislike of the discomfort of going through the building up of fitness and (c) a lack of belief that it is actually possible to be that fit. An ebike therefore would be like a security blanket (for an otherwise fit/healthy person). By the way, I am not talking about regular long commuting here in which an ebike plays a different role.

I would love to be able to measure her power output (and mine) and see just how far off she is from needed any e-assist.


I don't think it's that hard to measure power output, particularly on hills. If you install Strava on a phone and run it it will give you numbers.

In particular your weight and your bike weight are plugged in.

I think I have told it I am 85kg with a 9kg road bike and it tells me that over a 15 minute 4%/4km climb in the middle of a 4 hour ride I am averaging 213W.

If I try very hard I can get up to around 300w for say 5 minutes and for a short burst of a minute or so 400w.

I think the power meter people use a number they call 'functional threshold power' which is supposed to be 'all-out effort for an hour', though it's measured over a shorter timeframe because if you are putting out say 200W up a hill for 15 minutes you'll probably then go down it freewheeling just because of terrain. So it's a bit hard to measure.

Anyway I'm not sure how useful their numbers are in that if I am in practice putting out a bit over 200W up the longest sort of hill I encounter regularly then that seems a good number to use.

So if I take that over here

https://www.gribble.org/cycling/power_v_speed.html

And lets keep the power at 200w and ignore the various other numbers because it's uphill so they aren't that important (ok I upped drivetrain losses to 5%)

And if we have a hill of 7% then that is about 9.7kph/6mph

If we take that here

http://www.bikecalc.com/gear_speed

Then with a 50/34 and an 11-28 at 60rpm it goes down to 9.1kph

So in other words I can pedal in my lowest gear and easy cadence for a sustained hill of up to about 7%.

A long 10% hill and I'd be in trouble though I could manage the 300W for say 5 minutes. For extremely steep, say 20% then I need 400w to do only 7.4kph, which is 50rpm so possible but just briefly.

If I put out my 200W up the Hardknott Pass which is average 13.3% then that gives just 5.4kph. With 50/34 and an 11-34 that would be around 43rpm, so no thanks. But with a Shimano 'trekking' triple of 48/36/26 and an 11-36 you'd be right there in bottom gear at 60rpm.

As far as power to weight goes more generally, lets say I'm 85kg and I'm producing 300w for 5 minutes. That is 3.5W/kg. If I went to 70kg it would be 4.3W/kg.

However as we can see here there is a 21% power/weight ratio for men over women:
Image


So my 4.3W/kg as a lean 70kg would as a lean woman be only 3.5W/kg.

And then comparing total system weight:

Me + bike =95kg and 300w or 3.2W/kg
60kg woman of same relative W/kg power (relative to the average woman) + 10kg bike producing 60 * 3.5 = 210W that is then 3W/kg for the system

So even though I'm 15kg overweight and we both hypothetically have the same relative level of fitness, I still have an almost 10% advantage because of my sex and also because the weight of the bike becomes less significant when the rider is bigger.

(Note obviously that the more you weigh to start with the less it matters the weight of your bike, and equally the more gear you should carry when touring relative to your partner. )

So as far as your fitness versus your wife's assuming you are both the same age and not overweight then you have about a 20% advantage in power and assuming you are taller than she is, as most men are, then you have a further boost again as greater total power cancels put bike weight.

I suppose if you wanted to try and equalise things then you can either add an electric motor, which would completely overcome any shortcomings in that as per the example above you have let's say 200W vs. 133W but then add on a 250W (actually more in many cases) then you now have DOUBLE the total power. And the extra weight of the e bike is likely not relevant as the system weight of you and bike Vs wife and bike would likely be similar so you just have double the power on the e bike side.

As far as matching the e bike's performance with training goes, it's impossible. What you could do is establish current power levels and figure out what the difference is and perhaps put some lead weights on your bike to compensate :lol:

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horizon
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Re: Ribble SLE

Postby horizon » 3 Mar 2019, 1:42am

thelawnet: thanks tremendously for that. My daughter has Strava on her phone so on a forthcoming visit I'm going to ask her to check it. I reckon that MrsH might be in for a pleasant surprise: she is powerful uphill on the tandem (I can feel it) and there is probably a decent power output there. I just don't think she needs an ebike. We don't need to equalise (I'm happy to take it easy).
Let's just get Brexit done so that we can get on with the important job of re-joining the EU!

Roger_H
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Re: Ribble SLE

Postby Roger_H » 3 Mar 2019, 10:40am

Cugel wrote:
kwackers wrote:
Roger_H wrote:Do you think all the e road bikes have a similar set up?

Mine doesn't it's all cadence based.

On level one the max cadence is about 45 rpm, on two about 50 rpm and on 5 about 100rmp (just guessing at the numbers).
The motor starts to reduce power as you approach that cadence.

So pootling around on L1 simply means pedalling lazily, if you pedal faster then there's no input from the motor.
Still get a nice push off the start though.
Levels 3 & 4 have cadences that are similar to my normal riding so I'm just on the edge of what's comfy and I'm adding useful power to the bike whilst getting a useful amount of assist.

(There's also speed based limits, which are lower for the lower powers and higher for the higher ones).

It sounds a bit odd, and indeed it originally felt odd but after about 10 mins I'd gotten used to it. Now it's just second nature.


That's interesting. It seems, then, that there are various schemes implemented in different e-bike motor-controller software.

I had a hunt about after the last post about the Focus Parlane2 and found a user-downloadable software thing from Fazua that reports details of various kinds on the motor's behavior during a ride. It isn't clear, yet, how one obtains this data to populate such a report, though. I'll keep looking. I wonder if the LBS software interface, also available from Fazua, would allow tweaks to the power output profiles given in response to the controller setting, strain gauge measurements and wheel speed?

In passing, I also noticed a German manufacturer selling a cheater box for the Fazua, which one attaches in place of the rear wheel magnet sensor. This magic box then lies about the wheel revs, reducing the rev count reported to the motor software so that the motor will continue to work up to 20mph instead of cutting ut at 15.5mph. They want 150 euros for it, the rascals!

Personally I think the 15-5mph cut-off is fine - although something clever that could keep giving motor power up to 20mph but at a decreasing rate might be useful to club riders needing to keep up because their own wattage is compromised.

Cugel

What you've found out about different power delivery profiles is really interesting. It does indeed mean there is more to the issue than BB or rear hub motor.

Of curse some things are a given - for example a 250Wh motor is just that and my guess would be that means you've got around 200Wh of usable power which you can take how you want. Clearly some strategies will be more helpful for the battery than others, but even eeking out the power you're not going to get 400Wh from a nominal 250Wh battery!

There are various web pieces about how to hack e-bikes to take them over the EU's 25kph limit - but whilst this might give a thrill the battery won't have any more capacity! I guess there is a potential warranty issue here, but given the same bikes are sold in the US with a 30kph ceiling, there wouldn't appear engineering concerns in a few extra kph.

But thanks again - I'll try searching around the areas you've been looking at on power delivery strategies. (FWIW I couldn't decide if this type of thing was beyond the Ribble support team or they just didn't want to answer detailed questions about what they meant by "range up to"!)

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Re: Ribble SLE

Postby squeaker » 3 Mar 2019, 11:17am

Roger_H wrote:Of curse some things are a given - for example a 250Wh motor is just that....
Indeed, but remember that '250W' is the maximum continuous rated power, and it won't be available at all motor speeds...
"42"

Roger_H
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Re: Ribble SLE

Postby Roger_H » 3 Mar 2019, 11:21am

squeaker wrote:
Roger_H wrote:Of curse some things are a given - for example a 250Wh motor is just that....
Indeed, but remember that '250W' is the maximum continuous rated power, and it won't be available at all motor speeds...

Hands up! I said motor, I meant battery! Hope it makes a bit more sense if you reread with a mental C&P from motor to battery.

thelawnet
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Re: Ribble SLE

Postby thelawnet » 3 Mar 2019, 12:48pm

Roger_H wrote:
squeaker wrote:
Roger_H wrote:Of curse some things are a given - for example a 250Wh motor is just that....
Indeed, but remember that '250W' is the maximum continuous rated power, and it won't be available at all motor speeds...

Hands up! I said motor, I meant battery! Hope it makes a bit more sense if you reread with a mental C&P from motor to battery.


I would suggest you use the edit function as it's quite confusing as written

Roger_H
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Re: Ribble SLE

Postby Roger_H » 3 Mar 2019, 1:01pm

Roger_H wrote:
Cugel wrote:
kwackers wrote:Mine doesn't it's all cadence based.

On level one the max cadence is about 45 rpm, on two about 50 rpm and on 5 about 100rmp (just guessing at the numbers).
The motor starts to reduce power as you approach that cadence.

So pootling around on L1 simply means pedalling lazily, if you pedal faster then there's no input from the motor.
Still get a nice push off the start though.
Levels 3 & 4 have cadences that are similar to my normal riding so I'm just on the edge of what's comfy and I'm adding useful power to the bike whilst getting a useful amount of assist.

(There's also speed based limits, which are lower for the lower powers and higher for the higher ones).

It sounds a bit odd, and indeed it originally felt odd but after about 10 mins I'd gotten used to it. Now it's just second nature.


That's interesting. It seems, then, that there are various schemes implemented in different e-bike motor-controller software.

I had a hunt about after the last post about the Focus Parlane2 and found a user-downloadable software thing from Fazua that reports details of various kinds on the motor's behavior during a ride. It isn't clear, yet, how one obtains this data to populate such a report, though. I'll keep looking. I wonder if the LBS software interface, also available from Fazua, would allow tweaks to the power output profiles given in response to the controller setting, strain gauge measurements and wheel speed?

In passing, I also noticed a German manufacturer selling a cheater box for the Fazua, which one attaches in place of the rear wheel magnet sensor. This magic box then lies about the wheel revs, reducing the rev count reported to the motor software so that the motor will continue to work up to 20mph instead of cutting ut at 15.5mph. They want 150 euros for it, the rascals!

Personally I think the 15-5mph cut-off is fine - although something clever that could keep giving motor power up to 20mph but at a decreasing rate might be useful to club riders needing to keep up because their own wattage is compromised.

Cugel

What you've found out about different power delivery profiles is really interesting. It does indeed mean there is more to the issue than BB or rear hub motor.

Of curse some things are a given - for example a 250Wh motor is just that and my guess would be that means you've got around 200Wh of usable power which you can take how you want. Clearly some strategies will be more helpful for the battery than others, but even eeking out the power you're not going to get 400Wh from a nominal 250Wh battery!

There are various web pieces about how to hack e-bikes to take them over the EU's 25kph limit - but whilst this might give a thrill the battery won't have any more capacity! I guess there is a potential warranty issue here, but given the same bikes are sold in the US with a 30kph ceiling, there wouldn't appear engineering concerns in a few extra kph.

But thanks again - I'll try searching around the areas you've been looking at on power delivery strategies. (FWIW I couldn't decide if this type of thing was beyond the Ribble support team or they just didn't want to answer detailed questions about what they meant by "range up to"!)


I found this https://fazua.com/en/evation/know-how/ which is most interesting. It doesn't say what kind of variation the dealer can program - a pity.

Just to note, though, the Fazua motor is a BB drive whereas the motors I was asking about are rear hub based. In a recent co mic article, there was a suggestion that BB and rear hub motors were quite different in their characteristics and feel. And FWIW, I prefer the aesthetics of the bikes with a rear hub motor - though that's a very personal choice of course!

Sadly I still feel I'm really interested in the idea of an e-bike but their selling a propos range is very reminiscent of broadband speeds where ISPs quote up to 200 zillion and deliver 0.5 meg!