eBikes: I have some questions

Electrically assisted bikes, trikes, etc.
1982john
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eBikes: I have some questions

Postby 1982john » 27 Nov 2019, 1:41pm

In the new year I'm working on a new project which means my lovely 6-mile commute is now 14 miles. I've managed to avoid driving for 8 years and don't plan to change that now - especially as it's only for 6 months. However, I am not going to be able to do 28 miles a day 5 days a week, the train station is not in a convenient place and even if it was getting a bike on a train during rush is hell.

I'm considering an ebike. Never used one so I do have some questions. sorry if these are a bit obvious and I appreciate the help from these boards!

Is buying second-hand risky as you could end up with a knackered battery?

Key question: how much quicker would I expect to be vs my normal cycling speed commuting which I think is about 12mph. I really need to get this under an hour to be viable. If you went from a push bike to assist what difference did it make?

If a bike has a range of say 60km does that mean if I am putting in no effort or minimal effort? So if I'm putting in enough power to go 10mph it should massively up the range?

Many thanks!

Oldjohnw
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Re: eBikes: I have some questions

Postby Oldjohnw » 27 Nov 2019, 2:13pm

It isn't about speed. It's about being less tired.

Unless your trip is entirely flat effort is required but less than with human power. The more human effort and the lower the assistance setting, the longer your battery will last.
John

NickWi
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Re: eBikes: I have some questions

Postby NickWi » 27 Nov 2019, 2:19pm

1982john wrote:If a bike has a range of say 60km does that mean if I am putting in no effort or minimal effort? So if I'm putting in enough power to go 10mph it should massively up the range?


No, in fact the complete opposite, that'll be the most you'll get using the lowest power eco setting available with you providing most of the power. Think a bit like the MPG figures car manufacturers quote, i.e. in ideal test conditions, in a wind tunnel and God forbid, knowhere near a real road.

What you've got to remember with an ebike is that you're talking about a max assisted speed of 15.5mph (though you can pedel it faster if you can), you don't have a trottle and 250w isn't really that much power when it comes to the hills. If you're averaging 12mph now, yes, the right type of ebike may either improve you journey time and/or make it less effort, but I guess to be averaging 12mph now there are some sections when you're doing close to 15 or 16mph already. If this is the case I can't see and ebike dramatically raising your average speed. To average 14mph you need for your 1hr goal means your going to have to use max assist all of the time. This will have a big impact on range. As I said the right type of ebike ought to be able to offer that option, but I'll leave that recommendation to those that know more about that side of it than me.

freeflow
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Re: eBikes: I have some questions

Postby freeflow » 27 Nov 2019, 2:54pm

Mrs F's new ebike contributes the equivalent of 60% of the input power in eco mode (Bosch motor). If you are already able to average 12 Mph then you should be easily be able to achieve an average of 15.5 mph or faster over your commute distance. Mrs F has a 500 watt battery and is currently averaging 80 miles between charges.

1982john
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Re: eBikes: I have some questions

Postby 1982john » 27 Nov 2019, 3:56pm

freeflow wrote:Mrs F's new ebike contributes the equivalent of 60% of the input power in eco mode (Bosch motor). If you are already able to average 12 Mph then you should be easily be able to achieve an average of 15.5 mph or faster over your commute distance. Mrs F has a 500 watt battery and is currently averaging 80 miles between charges.


This is an encouraging response. I mean my range should be well within the parameters of most eBikes but I'm concerned if I forget one day!

I average 12 mph (on a nice day) for 6 miles but it would not be that over 14, my guess is it would go down to 10.5-11. My new route may be hillier as well whereas it's pretty flat at the moment.

I think I will just have to hire one and see what it's like. Really don't want a car :evil:

freeflow
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Re: eBikes: I have some questions

Postby freeflow » 27 Nov 2019, 4:25pm

Mrs F rides in eco mode or off. We did a 40km route on Sunday which took in 1200 ft of climb. It was quite cold but she still averaged 20 kph. Lots of low gradient 'up'. If your route is hilly then this is where an e-bike is of most use as upping the power will flatten the hills.

1982john
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Re: eBikes: I have some questions

Postby 1982john » 27 Nov 2019, 5:03pm

freeflow wrote:Mrs F rides in eco mode or off. We did a 40km route on Sunday which took in 1200 ft of climb. It was quite cold but she still averaged 20 kph. Lots of low gradient 'up'. If your route is hilly then this is where an e-bike is of most use as upping the power will flatten the hills.


Mapped the route and it's 13 flattish miles - only 300 ft climbing. What adds to the difficulty is I'm carrying a fair weight (on the bike not so much myself). So the double panniers does slow things down.

hemo
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Re: eBikes: I have some questions

Postby hemo » 27 Nov 2019, 5:43pm

Most 250w motors produce more then 250w temporarily if you select top assist level, typically 430w and if you have a higher ampage rated controller this can be up to 800w for 36v.

hemo
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Re: eBikes: I have some questions

Postby hemo » 27 Nov 2019, 5:45pm

1982john wrote:
freeflow wrote:Mrs F rides in eco mode or off. We did a 40km route on Sunday which took in 1200 ft of climb. It was quite cold but she still averaged 20 kph. Lots of low gradient 'up'. If your route is hilly then this is where an e-bike is of most use as upping the power will flatten the hills.


Mapped the route and it's 13 flattish miles - only 300 ft climbing. What adds to the difficulty is I'm carrying a fair weight (on the bike not so much myself). So the double panniers does slow things down.


With very little climbing nearly any bike will be good for that trip with a 10ah/300w battery, though a higher capacity battery is always a better option.

stodd
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Re: eBikes: I have some questions

Postby stodd » 27 Nov 2019, 5:58pm

Bosch range assistant gives a very good idea of range under different conditions. https://www.bosch-ebike.com/en/service/range-assistant/
Works pretty well for non-Bosch motors too. You have to do a little guesswork for motor type and riding mode but most motors are pretty similar efficiency.

You will see a factor of 3::1 between best conditions on good flat road in eco mode (often quoted by manufacturers, as mentioned by others above) and awkward hilly conditions.

hemo
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Re: eBikes: I have some questions

Postby hemo » 27 Nov 2019, 5:59pm

NickWi wrote:
1982john wrote:If a bike has a range of say 60km does that mean if I am putting in no effort or minimal effort? So if I'm putting in enough power to go 10mph it should massively up the range?


No, in fact the complete opposite, that'll be the most you'll get using the lowest power eco setting available with you providing most of the power. Think a bit like the MPG figures car manufacturers quote, i.e. in ideal test conditions, in a wind tunnel and God forbid, knowhere near a real road.

. To average 14mph you need for your 1hr goal means your going to have to use max assist all of the time. This will have a big impact on range. As I said the right type of ebike ought to be able to offer that option, but I'll leave that recommendation to those that know more about that side of it than me.


It depends on the controller and whether it is a speed control one or current control one.

Speed control means a controller gives max current in each assist level, though each assist level has a max speed limit. So yes max assist level would be required which will eat in to the battery capacity/range.

Current control is the opposite and gives you better power/torque control and more battery range. They have 5 assist levels of current and give max speed if required in each one , so you can ride quite happily along drawing low current until you need a boost then temporarily up the assist/current level.

I can toot along at 16mph on my ebikes in only assist level 1 or 2 of 5, this conserves power and saves it for any hills for which then assist 4 or 5 is temporarily used.

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Cugel
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Re: eBikes: I have some questions

Postby Cugel » 27 Nov 2019, 6:38pm

NickWi wrote:
1982john wrote:If a bike has a range of say 60km does that mean if I am putting in no effort or minimal effort? So if I'm putting in enough power to go 10mph it should massively up the range?


No, in fact the complete opposite, that'll be the most you'll get using the lowest power eco setting available with you providing most of the power. Think a bit like the MPG figures car manufacturers quote, i.e. in ideal test conditions, in a wind tunnel and God forbid, knowhere near a real road.

What you've got to remember with an ebike is that you're talking about a max assisted speed of 15.5mph (though you can pedel it faster if you can), you don't have a trottle and 250w isn't really that much power when it comes to the hills. If you're averaging 12mph now, yes, the right type of ebike may either improve you journey time and/or make it less effort, but I guess to be averaging 12mph now there are some sections when you're doing close to 15 or 16mph already. If this is the case I can't see and ebike dramatically raising your average speed. To average 14mph you need for your 1hr goal means your going to have to use max assist all of the time. This will have a big impact on range. As I said the right type of ebike ought to be able to offer that option, but I'll leave that recommendation to those that know more about that side of it than me.


Do you ride an e-bike or have you done a significant ride on one? I'm guessing not as many of the things you say here are just wrong.

250W is a large amount of power on a bike. I know time trialists who average that power output over a 25 mile ride (no motor) and do under the hour. Even half of that (typical eco mode on a lot of e-bikes) will mean an average cyclist (not the racy type) will have 200-250 watts in eco mode, adding their own pedalling effort of 75 - 125 watts to the motor's 125 watts.

The ladywife has an e-bike and she can easily do 15.5mph in eco mode on a flat road, on a windless day. Easily. She's not super fit but finds that speed no effort. In the middle power level she can be doing 10 mph up significant slopes, usually dropping me if the slope is both steep and long. And I'm an ex-racy cyclist able to put out around 220 watts for 20 minutes or perhaps longer, with one - two minute bursts of 300 watts before I blow.

If the OP averages 12 mph now, he will easily manage 15.5mph average over the same route, probably in eco-mode only, on an e-bike. If there are more hills and distance, the middle power level is likely to enable him to keep that 15.5mph average. It gets harder to increase the average above 15.5 mph as there's more wind resistance as one goes a lot faster; more weight with a heavier e-bike to push up slight slopes; and no motor power of course. Even so, it may be possible for him to average 17 or even 18mph for the whole route, depending on the nature of the route and on weather conditions.

On a 26 mile ride with 1002 metres of climbing (and descent) the ladywife can still have 20% of her 250 wh battery left with her e-bike. A bike with a 400 or 500 wh battery will easily last 40 - 50 miles even with significant use of higher power; up 80 or a 100 miles if eco mode only is used - assuming the cyclist is not very unfit but can themselves output around 100 - 125 watts average for the whole ride. Most club cyclists (including the non racing types like me) can average 180 - 220 watts without blowing up, as a comparison.

Cugel

NickWi
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Re: eBikes: I have some questions

Postby NickWi » 27 Nov 2019, 7:31pm

Cugel wrote:Do you ride an e-bike or have you done a significant ride on one? I'm guessing not as many of the things you say here are just wrong.
Cugel


An Orbea Gain actually and have done rain or shine for the last 18months.

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Cugel
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Re: eBikes: I have some questions

Postby Cugel » 27 Nov 2019, 7:44pm

NickWi wrote:
Cugel wrote:Do you ride an e-bike or have you done a significant ride on one? I'm guessing not as many of the things you say here are just wrong.
Cugel


An Orbea Gain actually and have done rain or shine for the last 18months.


Have you remembered to switch it on? :-)

Cugel

NickWi
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Re: eBikes: I have some questions

Postby NickWi » 27 Nov 2019, 7:59pm

Cugel wrote:Have you remembered to switch it on? :-)
Cugel


If you wish to make personal insults, that's fine, fire away I've got a thick skin, but it does help the OP with his question does it. Does anyone actually have some recommendations as to what make & model might suit the OPs needs bearing in mind he's expanded on the type of ride it'll be.

From my side I actually wouldn't recommend an Orbea Gain. That may sound a bit strange as some of the F series they do make excellent urban bikes, but I feel the relatively low torque of the motor and small battery wouldn't meet the needs of the OPs needs in needing to average 14mph plus.