ebike to keep up with road bike for 40 miles

[doclatham]

I'm looking for an ebike for my wife so that she can come with me on bike rides.

I'll. Be on my conventional road bike, probably averaging 17 mph for say 40 miles round trip with a stop for a cup of tea half way.

There will be some hills but I'm lazy so nothing too steep

Is this realistic? I see that ebikes are limited to about 15mph but I imagine on the flat or downhill my wife will go faster than this and on the up hill sections I'll be going slow, although I hope she'll ride with me and not shoot off over the horizon.

PS if the bike can be suitable for both men and ladies I'd like to borrow it for my 20 miles commute (with big hills) as we have no showers at work.

We live in Preston Lancashire as far as text rides and support are concerned

Thanks in Advance

D

 

[RobF]

Doc,

Averaging 17mph over 40 miles is fast-ish club roadie pace, so you will take some keeping up with.

Assistance on legal ebikes stops at about 15mph, and while the better ones have little pedal resistance from the motor above that speed, your wife will still be trying to propel a 25kg bike with no assistance which you will know is hard work.

So much may depend on her level of physical fitness.

Is she an experienced cyclist?

Maintaining a 17mph average is going to involve some fast descending and cracking on elsewhere when possible.

From a safety point of view, it's not something I would ask a new cyclist to do.

As regards a suitable bike, are you prepared to buy an illegal de-restricted one?

They are no balls of fire, but probably would enable Mrs D to keep up with you.

There is a Kalkhoff may do what you seek, it assists to 28mph, and just as importantly has a big battery.

It's possible to de-restrict or buy a de-restricted Bosch-equipped bike - I have one - and such a device would do the job speed-wise.

But the biggest Bosch battery is 11ah, which is going to be up against it trying to do 40 miles at pace.

Hence my suggestion of the Kalkhoff, which has about half as much more capacity.

http://www.50cycles.com/electric-bikes/endeavour-sport-fast/endeavour_impulse_s10_xt.html

 

[Alan Quay]

Or, if you are handy you can build something from a kit that will meet your requirements.

 

[Geebee]

Not that hard, an Ezee will cruise at 32 kph which is close enough to 20 mph with minor pedalling, range may require the bigger battery that they offer to maintain it though dependent upon rider input, 32 kph is very light pedalling,
A Tonaro with the rear magnet moved slightly out of line will do similar.

 

[Backin5]

How tall is your wife? A lot of blokes on here often forget that 5' 1" women struggle to find bikes to fit them, especially quick ones with 40 miles of battery. Obviously a step through would work best.

Just something to bear in mind - unless she's 6' 6"?

 

[doclatham]

Thanks for the speedy responses. You all seem to get up a lot earlier than I do on a Bank Holiday.

I certainly wouldn't consider myself as "fast ish" so I guess my speedometer is reading wrong, although I tend to keep to the flat.

My wife used to be a competent mountain biker, but is now in (very) late 40's and frankly a bit over weight, thus the attempt to get her back on her bike. (Boy am I in trouble if she ever reads this).

So, if I downgrade my spec to needing to average 15mph over 40 miles, does that get more realistic?

I would be tempted by derestricted just to get the extra couple of mph, nothing mental like I see on YouTube!

Is there anywhere in Lancashire where you can test ride these bikes, ideally borrow/rent one for a day?

I think I could install a kit, but I'd want it to look good as well.

PS I was looking at BH emotion neo race or cross for my own commute but was put off by stories of spoke problems. then one reseller I spoke to said they weren't selling them any more as support was so poor and then I see UK distributor has pulled out?

 

[oldtom]

I'll. Be on my conventional road bike, probably averaging 17 mph for say 40 miles round trip with a stop for a cup of tea half way.

There will be some hills but I'm lazy so nothing too steep

Is this realistic?

If you had asked, 'Is this possible?', I would say yes but you asked if it were realistic therefore I have to say no.

17 mph is a good pace over 40 miles and is beyond the ability of most leisure cyclists. Certainly, club riders can manage that sort of pace and distance but those people are strong athletes and they usually propel extremely lightweight bikes.

If your other half happens to be a fit, strong athlete, she might well be able to keep up with you on the right road bike but if she isn't, then her chances of propelling any legal ebike at that pace over 40 miles are remote. Those bikes which might do the job are entirely illegal but if you're happy for your wife to expose herself to potential prosecution, fine.

It seems to me that the whole ethos of electrically-assisted bicycles is undermined every time the answer to questions such as yours requires recommendations for illegal bikes.

Tom

 

[Arbol]

I cannot give answers to your questions.

However, let me highlight that there should be some "error limits" in the max speed limits.

For example, I am in Spain, and max speed limits are 120km/h in highways. However (at least a few years ago, things may have changed) radars have a 10% error limit, so any speed below 132km/h is not considered illegal.

In the same way, moped speed limit is 45km/h. However, it is standard that road legal mopeds, sold by good brands, have a real max speed limit in the mid to high 50km/hs. The reason is the technical inspection laboratories have error limits, and moped brands take advantage of that.

So, I tend to believe (but not 100% sure) that 17mph should be within reasonable limits, in most jurisdictions, a legal speed, even if legal max speed is 15mph. Heck, it is only 2mph! measurement errors of standard measuring devices are probably higher than that.

Definitely, I would like to hear what experts have to say about this issue.

 

[RobF]

Spokes can be a problem on hub drive bikes, but equally a properly built wheel will do the job.

As with most things, the chances of you getting a quality item are improved the more you pay for it.

I think there are more spoke problems with porky 20 stone plus blokes, so the relatively weight of the wife will help.

Whatever bike you buy, you will need at least a 15ah battery, which limits your choice quite a lot.

A mid-priced alternative - if you are prepared to carry a second battery - would be something from Kudos which have 10ah batteries, so you would need to add £200 for a spare.

http://www.kudoscycles.com/

 

[Arbol]

Also, and despite having little practical experience, I believe a reasonable motor with a good battery should do what you need for your wife.

The reason is a 36V 15A, standard / cheap and fully legal, configuration gives 540W of power. Miguel Indurain, going up the Alp d'Huez in his best years, could possibly provide for little more than 400W for limited periods of time.

So, even if your wife can only provide say 60W constantly, a reasonable motor (legal and cheap) could provide one and a half Indurains, all the time!

I suspect the reason most 36V 15A kits / bicycles undeperform massively what I have described (apart from losses; at the wheel, power is less than 540W) is that standard batteries are crap, and they never provide 15A constantly.

My hunch is that if you buy / build an overengineered battery, with many Ahs and a decent discharge rate, you will not be able to follow your wife.

But I could be wrong.

 

[Geebee]

If you had asked, 'Is this possible?', I would say yes but you asked if it were realistic therefore I have to say no.

17 mph is a good pace over 40 miles and is beyond the ability of most leisure cyclists. Certainly, club riders can manage that sort of pace and distance but those people are strong athletes and they usually propel extremely lightweight bikes.

If your other half happens to be a fit, strong athlete, she might well be able to keep up with you on the right road bike but if she isn't, then her chances of propelling any legal ebike at that pace over 40 miles are remote. Those bikes which might do the job are entirely illegal but if you're happy for your wife to expose herself to potential prosecution, fine.

It seems to me that the whole ethos of electrically-assisted bicycles is undermined every time the answer to questions such as yours requires recommendations for illegal bikes.

Tom

Tom, read my response the Ezee will do it no problem and is a legal bike if somewhat powerful for 250w and with zero mods, I am, due to illness incapable of putting out very much power at all but could still sit on 32 kph (20mph) with almost no pedal assist when test riding one.

 

[trex]

...
I suspect the reason most 36V 15A kits / bicycles undeperform massively what I have described (apart from losses; at the wheel, power is less than 540W) is that standard batteries are crap, and they never provide 15A constantly.

My hunch is that if you buy / build an overengineered battery, with many Ahs and a decent discharge rate, you will not be able to follow your wife.

But I could be wrong.

With regard to kits, any Chinese battery can do 1.5C, batteries with high discharge rate BMS are limited to 1000W and usually fitted with Samsung cells.
For Mrs D, a Woosh CD would do well. All the Woosh CDs have Samsung cells
I recommend a crank drive because their maximum speed is only limited by your cadence.

 

[martin@onbike]

PS I was looking at BH emotion neo race or cross for my own commute but was put off by stories of spoke problems. then one reseller I spoke to said they weren't selling them any more as support was so poor and then I see UK distributor has pulled out?

[/QUOTE]

Hi Doclatham,
BH did indeed have spoke issues on their earlier releases of the Neo range, but this was addressed some time ago now.
The distribution was changed from Maxtrack to BH-UK last year with no interuption in availability of bikes.
As a dealer, the back-up from BH has been equal to any of the other brands I deal with, although they are slower to respond, particularly in August when Spain goes on "Siesta".
The Neo Race has great power to weight at 19kg, but I think you would struggle to get 40 miles out of the 11.6Ah battery with high assistance...though it's achievable on a lower setting.
I have one coming in on Wednesday...If you wish to see it and possibly try it, I can ask the chap buying it if he wouldn't mind you having a quick go.

 

[Backin5]

So, how tall is your wife?

The battery on my other halfs Cyclamatic ran out before the end of a ride a couple of weeks ago, and she pootled back on my Neo Xtrem. She's 5' 2" and said it was like being perched on a penny farthing.

She did say it went like a rocket though.

I cruise on it around 17 - 18 mph in standard power mode. I'd get around 30, maybe 40 miles out of it with gentle hills.

 

[Arbol]

With regard to kits, any Chinese battery can do 1.5C, batteries with high discharge rate BMS are limited to 1000W and usually fitted with Samsung cells.

What is the way out then? I see people arguing a 36V 15A standard motor is not enough to cope with hills, and even a lycra guy could beat them.

But a watt is a watt, and 36V 15A provides for 540W. Ok, take 30% due to losses, but you are still at Tour de France performance levels.

I cannot understand how a kit able to provide continuously 36V 15A is not able to go up any hill, no matter how steep, if a Tour de France biker can, too.

The only possible explanation is the kit is not giving 36V 15A support, but much less.

Or is there another possible explanation?

 

[trex]

all the crank drives can get up steep hills - albeit slowly. Most of the legal cank drives have maximum output at around 500W, they can maintain this output only at the optimal gearing, in the case of the BBS01 / TCM / MMS translates to around 70-75 RPM, which may be not the case when climbing very steep hills, with you being limited by the choice of available gears.
At present, the most powerful CD you can buy is 750W 48V 25A BBS01 but from June, XOFO has a similarly rated motor but cheaper, then a bit later, MXUS.

 

[Arbol]

Thanks trex. But I am not thinking about sofisticated 750W crank drives. I am thinking about simple 250W nominal hub motors, such as a Q100, at 36V and 15A. These motors should be able to provide for 540W, no matter what gear the biker is in. 540W should be able to go up very steep hills. Of course, the limit may be the rpm of the motor. If rpm is too high, the motor will not be able to cope with it. I assume this is the same with Indurain trying to go up the Alp d'Huez with a big crank and a small freewheel at the rear. But assuming a reasonable gearing, a hub motor should be able to cope with any hill in the world (if a biker can).

 

[oldtom]

I am, due to illness incapable of putting out very much power at all but could still sit on 32 kph (20mph) with almost no pedal assist when test riding one.

Perhaps I'm missing something here Geebee or it may be I'm just really thick. Correct me if I'm wrong but in order for an EAPC to comply with European legislation, the motor assistance must cut off at 15 mph although a marginal tolerance is permitted which could conceivably allow a smidgin more than that.

If you are telling me that an Ezee bike can permit 20 mph with next to no pedalling, that suggests there is still electrical assistance at work therefore the bike must be illegal? Last time I looked, most Ezee machines were of the order of 26-28Kgs including battery.

I note your address is Australia so perhaps different power limits apply there.

Tom

 

[Geebee]

Perhaps I'm missing something here Geebee or it may be I'm just really thick. Correct me if I'm wrong but in order for an EAPC to comply with European legislation, the motor assistance must cut off at 15 mph although a marginal tolerance is permitted which could conceivably allow a smidgin more than that.

If you are telling me that an Ezee bike can permit 20 mph with next to no pedalling, that suggests there is still electrical assistance at work therefore the bike must be illegal? Last time I looked, most Ezee machines

I note your address is Australia so perhaps different power limits apply there.

Tom

Same regulations these days, there is a degree of tolerance and the Ezee seems to push that to the limit, which makes for a legal bike that is a smidge quicker.
There is a chance that the bike I read wasn't representative but others may be able to chime in.

 

[Deleted member 4366]

Also, and despite having little practical experience, I believe a reasonable motor with a good battery should do what you need for your wife.

The reason is a 36V 15A, standard / cheap and fully legal, configuration gives 540W of power. Miguel Indurain, going up the Alp d'Huez in his best years, could possibly provide for little more than 400W for limited periods of time.

So, even if your wife can only provide say 60W constantly, a reasonable motor (legal and cheap) could provide one and a half Indurains, all the time!

I suspect the reason most 36V 15A kits / bicycles undeperform massively what I have described (apart from losses; at the wheel, power is less than 540W) is that standard batteries are crap, and they never provide 15A constantly.

My hunch is that if you buy / build an overengineered battery, with many Ahs and a decent discharge rate, you will not be able to follow your wife.

But I could be wrong.

You're getting mixed up between input and output power. The torque of a hub-motor goes up as the speed goes down, ut the efficiency goes down rapidly as the motor slows down. When climbing a steep hill, your efficiency can go as low as 20% or even less, so your 600w of input power only gives 120w of output, which isn't enough to drag 100kg up a steep hill, so it stalls out.

The Xiongda motor with its lower gearing can keep going long after the others have stalled out. It's nearly the same as a crank-drive in first gear, which can also keep going slowly depending on the gearing. The lower the gearing, the steeper the hill you can climb, but the slower you go.

You should have a play with the simulator to see what happens between input and output power when climbing, and how much power you need to climb hills. It will make more sense then:

http://www.ebikes.ca/tools/simulator.html

You can't use the simulator for crank-drives. For them, you have to consider the crank rotation speed. You get more torque by letting the rotation speed drop off, but then you get the same inefficiencies as a hub-motor. For efficiency, you need high crank rotation speed, but then you get no torque. This is where hub-motors gain an advantage where you can get high torque independent of pedal speed.