Going electric

[andyoxon]

My 2p.  On a local walk, I got talking to a lady cyclist in her 80s.  She was walking her very new looking & 'substantial' e-bike, and said that she was returning it to the bike shop to sell it for her, because she found it too heavy too manage given her wrist and finger arthritis.  My f-i-l in his 90s bought a lightweight Ribble road e-bike, which he finds v.good, particularly for hills - not cheap though.

[robgul]

A further 2p here - I had an Orbea Gain (rear wheel motor, non removable battery - pretty much same as the Ribble) - it was OK but a friend offered me £50 less than I paid for it after 2 years so I sold it in May 2021.

Bought a Boardman Adv8.9e in Feb 2022 (£2,600) excellent and the Fazua system to remove battery + motor (and ride as an ordinary bike should you wish) is handy - for charging and handling/transporting the machine.  A second battery to carry is an option with not a lot of weight penalty.   There is a flat bar version of the same bike at bout £2,200.  So far range has been fine - 50-60 miles and I still have one, of five, battery lights on.

[Kim]

Sag is just what e-bike people call the voltage drop due to internal resistance of the battery.  I'm not entirely sure why.

Stands to reason that if you put two identical batteries in parallel you'll halve the resistance at a given level of discharge compared to a single battery at the same level of discharge.  Of course, since you've doubled the capacity you'll take about twice as long to get to that point, too.
…

The “identical” bit makes me nervous, especially if one gets left at home sometimes for short trips to the shops. Maybe I’m out of date with new tangled batteries and how they discharge and age, but “two identical” sounds to me somewhere between exam question glossing over details and “a long time ago in a land far away”.

Yes; if you connect two batteries with different voltages (eg from different charge states) in parallel, current would flow from one to the other until it equalises.  This is bad, not just because it wastes energy with the charge/discharge inefficiency, but because there might be quite a lot of current.

No doubt that any system combining two batteries that *aren't* permanently wired together does something with diodes or MOSFETS or whatever to prevent this from happening.  The simple diodes circuit will preferentially draw current from whichever has the higher voltage.  More devious strategies are available.

[mzjo]

As a rough indication of what to expect, putting a motor on my old warhorse added just under 8 kg including motorized 700c wheel, battery, battery mount inc control unit, cables & HB console.  The battery alone was 1.5 kg and I need a rack + saddlebag to schlepp my spare.

 This is a clubmate's tourer fitted with a conversion from Annad. They are not the cheapest and there are now at least a couple of other suppliers (all in France, the UK must have similar conversion suppliers). From the photo he posted M.T42's conversion looks to be similar but all the ones in the club (there are about 8 at the last count) claim 5kgs, not 8. All fitted to the owner's existing bike, the only requirement being enough clearance to fit a 25mm tyre. The owner of this one (weak heart) regularly finishes 100km rides with 60% battery capacity left! (Mainly because riding a bit steadier and spinning a bit more on the hills - as advised by the maker - seems to draw a lot less power from the battery.) But the conversion is expensive!

[Canardly]

A further 2p here - I had an Orbea Gain (rear wheel motor, non removable battery - pretty much same as the Ribble) - it was OK but a friend offered me £50 less than I paid for it after 2 years so I sold it in May 2021.

Bought a Boardman Adv8.9e in Feb 2022 (£2,600) excellent and the Fazua system to remove battery + motor (and ride as an ordinary bike should you wish) is handy - for charging and handling/transporting the machine.  A second battery to carry is an option with not a lot of weight penalty.   There is a flat bar version of the same bike at bout £2,200.  So far range has been fine - 50-60 miles and I still have one, of five, battery lights on.

Rob, when suppliers quote mileage ranges are they quoting minimum/maximum effort from the rider? The range quoted for the Boardman is puzzling i.e. 25-30 with a max of 60?

[Paul H]

A further 2p here - I had an Orbea Gain (rear wheel motor, non removable battery - pretty much same as the Ribble) - it was OK but a friend offered me £50 less than I paid for it after 2 years so I sold it in May 2021.

Bought a Boardman Adv8.9e in Feb 2022 (£2,600) excellent and the Fazua system to remove battery + motor (and ride as an ordinary bike should you wish) is handy - for charging and handling/transporting the machine.  A second battery to carry is an option with not a lot of weight penalty.   There is a flat bar version of the same bike at bout £2,200.  So far range has been fine - 50-60 miles and I still have one, of five, battery lights on.

Rob, when suppliers quote mileage ranges are they quoting minimum/maximum effort from the rider? The range quoted for the Boardman is puzzling i.e. 25-30 with a max of 60?

Can't answer for Rob - I've found the Bosch range calculator to be accurate, as long as the parameters are realistically set. I don't know how much difference there is between systems, once adjusted for battery size I suspect decent mid drive motors will have a similar efficiency.  If nothing else it gives an idea of how the parameters (Rider, bike, environment) effect the range, which could be a useful comparison tool even if the numbers are inaccurate.

https://www.bosch-ebike.com/en/service/range-assistant

[robgul]

A further 2p here - I had an Orbea Gain (rear wheel motor, non removable battery - pretty much same as the Ribble) - it was OK but a friend offered me £50 less than I paid for it after 2 years so I sold it in May 2021.

Bought a Boardman Adv8.9e in Feb 2022 (£2,600) excellent and the Fazua system to remove battery + motor (and ride as an ordinary bike should you wish) is handy - for charging and handling/transporting the machine.  A second battery to carry is an option with not a lot of weight penalty.   There is a flat bar version of the same bike at bout £2,200.  So far range has been fine - 50-60 miles and I still have one, of five, battery lights on.

Rob, when suppliers quote mileage ranges are they quoting minimum/maximum effort from the rider? The range quoted for the Boardman is puzzling i.e. 25-30 with a max of 60?

IME with both of my ebikes (and selling quite a few of various brands when I managed a bike shop) ALL info about "range" is unreliable!   Too many factors to take into account . . . amount of battery/engine power level used and for how long, steepness of hills, headwind/tailwind, rider effort put in pedalling/use of gears. So, no real answer to your queston.

I haven't tried it but I'm guessing that if I rode my Boadman on "red" max battery/engine it'd probably do 25/30 miles at close to max speed (25km/h) on the flat.

These bikes are really for "assistance" rather than as a "motorcycle" - like many people I ride mine without the battery/engine when I'm comfortable doing so, engaging the motor for hills beyond my comfort level . . or if I'm tired/riding into a headwind.

[On a personal note - I was seriously ill 8 years ago and had some major surgery which signicantly affected my core strength . . .  recovery has been quite good BUT I was struggling to keep up with the other club riders (I'm also 75!) - hence the ebike for assistance.   I pretty much ride the Boardman on club runs but if on my own usually ride a normal bike - Van Nic road or tourer]

[L CC]

I (fat) ride mine mostly to work or the pool. Either way, it's fairly loaded and there is an unavoidable climb of at least 250m.

I usually get there and back with just under 50% remaining, but cold weather (this is County Durham) this drops quite a lot.

The appallingly named Mission Control App gives good guesstimates if you ask it.

I have it at max assist all the time- I'm never going to be worried about range with a max daily journey of 40km.

[Kim]

Absolute worst-case range is simple: Battery capacity in Watt-hours divided by 250W multiplied by 25km.  That's not allowing for the effects of 'sag', or the motor not being able to achieve full speed up bastard hills, but it'a also not allowing for the fact that you won't need anything like 250W to do 25kph most of the time, especially if the rider is contributing some effort.

Anything else is suck-it-and see, as it'll depend on all the usual things that affect cycling efficiency: mass, gravity, wind, tyres, aerodynamics etc.  Not to mention the real-world performance of the battery, especially when it's cold^[1].

E-bike manufacturers know a lot about the performance of their electric-assist system, but not about how you're using the bike, they can only apply a fudge-factor.  And it's not like WLTP range in cars, which everyone knows is unrealistic, but is at least consistent across manufacturers.  It's more like those ASA-mandated 'average' broadband speeds, which are effectively meaningless.


_{[1] I expect there's a 'bikes are sports equipment and only ever ridden in decent weather' factor here.}

[Steph]

Lots of good stuff here. I saw this ad today, which is sort of what I am looking for

https://www.allterraincycles.co.uk/trek-fx-electric-city-bike-2023-?s=googleshoppingppc&msclkid=13da9ee3bf64163bb201fd2c02b27bab&utm_source=bing&utm_medium=cpc&utm_campaign=Standard%20Shopping%20-%20Bikes%20%5BeCPC%5D%20MM&utm_term=4582283443549419&utm_content=PL%20-%20Trek%20MM

[Sergeant Pluck]

Just to throw another factor into the mix - charging time. Being able to charge quickly could, depending on circumstances, make smaller batteries like the one on the Trek more practical. The Bosch 400Wh battery on the Tern charged astonishingly quickly with the rather chunky charger it came with.

[L CC]

I'd've bought that Trek if it had been in the shop the day I bought mine.
Mine's got a bigger battery (320) and is lighter... but I've paid quite a lot for the privilege.

I think the Trek's got a lower crossbar too, which would be in its favour, for me anyway.

[JennyB]

Just to throw another factor into the mix - charging time. Being able to charge quickly could, depending on circumstances, make smaller batteries like the one on the Trek more practical. The Bosch 400Wh battery on the Tern charged astonishingly quickly with the rather chunky charger it came with.

Yes, the ability to charge 40% to 80% in under an hour is a game-changer (the last 20% is always a lot slower). I was doing that on my Audax adventure ten years ago, but it meant using two noisy chargers and wasn't at all good for the battery.


Overall I reckon an ebike will take me 30-50% further for the same effort that I could go unassisted. I have gone as low as 3 wh/km on a long slightly hilly ride and still been very glad of help, on the basis that you don't notice the weight where you don't need the power.

[Kim]

Just to throw another factor into the mix - charging time. Being able to charge quickly could, depending on circumstances, make smaller batteries like the one on the Trek more practical. The Bosch 400Wh battery on the Tern charged astonishingly quickly with the rather chunky charger it came with.

Shirley the charge rate is determined mostly by the charger, not the size of the battery?  Given a constant charging current and the same voltage, a smaller battery will be more full after the same amount of charging time, but the amount of energy you've put into it will be the same.  (If anything, the larger battery has a slight advantage here, at it's less likely to get to the point where the charging current starts to taper off...)

I also note that - as a general rule - larger batteries tend to come with more powerful chargers...

[Wowbagger]

I'd agree. As long as you get as many miles in the battery as you need, that's all that matters. My bike's battery is pretty big - good for 70 Essex miles as long as it's not too cold, with an enormous Bagger perched atop. For normal urban pottering I don't bother to charge it up until it's less than 50% full, but if I were planning a proper ride I'd make sure it was full.

[Sergeant Pluck]

Shirley the charge rate is determined mostly by the charger, not the size of the battery?.

Yes, of course. But some systems with similar battery sizes come with better chargers than others, so if one is forced to have a smaller battery, 250Wh say, then choosing a system (battery + charger together) with a shorter charging time could help offset some of the disadvantages of having a smaller battery when out on the road, depending on circumstances such as ability to have a charger at work, feasibility of actually carrying a charger etc.

[JennyB]

Shirley the charge rate is determined mostly by the charger, not the size of the battery?  Given a constant charging current and the same voltage, a smaller battery will be more full after the same amount of charging time, but the amount of energy you've put into it will be the same.  (If anything, the larger battery has a slight advantage here, at it's less likely to get to the point where the charging current starts to taper off...)

I also note that - as a general rule - larger batteries tend to come with more powerful chargers...

Cells are C-rated for charge and discharge, where 1 C is the rate that would theoretically completely fill or empty it in a hour. For batteries of the same cells, the charge or discharge power  limit is directly related to the size of the battery. Most battery management systems restrict charging to well be the limit in order to preserve battery life. The way round this was to 'bulk charge' with a second charger on the discharge leads, bypassing the BMS, and be sure to stop charging well before capacity. 

[DuncanM]

This is probably not relevant for the OP, but is very much related to going electric and what you get for your money. I wasn't sure where to post it - includes tragic consequence from e-bike crash.
https://www.bicycling.com/culture/a42690937/molly-steinsapir-lawsuit-rad-power-electric-bike/?s=03
Mods - if this belongs as a discussion topic in On The Road (or somewhere else) then please feel free to move it there.

[Frank9755]

It's not at all relevant:

Firstly the crash happened when they were going downhill, so it's not really about e-bikes but about bikes and hills.

Secondly, children of that age cannot ride ebikes in the UK or EU - so the central point of the article - unregulated industry - does not apply, as the industry here is regulated.

If you want to post this rubbish - and others may have a higher opinion of it than I do, so why not - it would be polite to put it in a separate thread rather than lobbing it into one for which it really is irrelevant.

[Kim]

I'd agree that USAnia provides a useful comparison for what happens when e-bikes aren't regulated as they are in the EU.  However, it's completely irrelevant to this thread, as Steph wants a bike for use in the UK and possibly Europe.

[DuncanM]

That Radpower bike, with the same cheap mechanical brakes, is available here as well as the US. Having checked, I'm now inundated with adverts for them. They are more city bike than OP suitable bike, but they illustrate an issue of getting much lower spec bike for your money because of the electrics (even if they are significantly more than a grand) and that's why I posted it on this thread rather than on an entirely new ebike thread.

[Ham]

Another prospective purchaser interested in this thread, Mrs Ham would like one. I suspect she may need a step through now, too, which seems to up the weight no inconsiderable amount. (Un?)Surprisingly, Spesh don't quote weight for theirs, but [urlhttps://www.specializedconceptstore.co.uk/product/25248/2022-turbo-como-3-0/]this step through[/url] appears to clock up about 29Kg. This at a credible 18Kg seems a bit better

[Wowbagger]

Mine is a behemoth. It weighs almost 30kg. I've been on a couple of off-road rides when I've had to lift it over a stile or fence because I've been cycling along what was technically a footpath. I'm pretty big and strong and I practise weightlifting. However, I'm also rapidly approaching my 69th birthday and I can't see that anything I do exercise-wise is going to do anything better than slow the decline, rather than make me fitter and stronger.

I can make it a bit lighter for lifting purposes by removing the battery and putting it back again when I've lifted it. That's not insignificant because the battery to mine (625Wh Bosch) weights about 4kg.

[L CC]

Another prospective purchaser interested in this thread, Mrs Ham would like one. I suspect she may need a step through now, too, which seems to up the weight no inconsiderable amount. (Un?)Surprisingly, Spesh don't quote weight for theirs, but [urlhttps://www.specializedconceptstore.co.uk/product/25248/2022-turbo-como-3-0/]this step through[/url] appears to clock up about 29Kg. This at a credible 18Kg seems a bit better

If Mrs Ham is tall enough this is what I wanted. At 163cm I’m definitely a small, and those have been OOS all year.

[Paul H]

Another prospective purchaser interested in this thread, Mrs Ham would like one. I suspect she may need a step through now, too, which seems to up the weight no inconsiderable amount. (Un?)Surprisingly, Spesh don't quote weight for theirs, but [urlhttps://www.specializedconceptstore.co.uk/product/25248/2022-turbo-como-3-0/]this step through[/url] appears to clock up about 29Kg. This at a credible 18Kg seems a bit better

I think the extra weight is largely the type of bike rather than the frame shape.  There's a trend for something between a conventional height top tube and a true step through.  Manufacturers offering all three have had to come up with different names for the middle one, Stagger in Trek speak. It gets confusing as manufacturers who offer two styles have stuck with the step-through name for frames others would call New-name,  I have a Trek Allant, it comes in three variations, standard, Stagger, Lowstep, the weights are all within a few grams of each other, in sneaky Trek style the quoted weights are without the battery, my XL standard with a 500Wh battery weighs 24kg. That doesn't seem excessive, a similar style non assisted bike is likely to be 18kg.