Effort or Speed?

Electrically assisted bikes, trikes, etc.
Bonzo Banana
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Re: Effort or Speed?

Postby Bonzo Banana » 3 Jul 2020, 8:01am

willcee wrote:I would question you on where you think or even know where the torque you claim disappears.. where it ends up ...cause it does not disappear ...nor is it lost in the chain... I know from thousands of fast miles that my unmodded 1 hp Mid Motor with a claimed 80/100 nm takes me 200 and a 52lb bike 252 approx lbs to 35 odd mph where attainable on the flat like the proverbial wind at a high cadence and in no way would a lesser torque figure manage that pulling a 46x11.. not forgetting that the torque is available from 10rpm to 120rpm ..will


I'm only stating well documented power losses through the chain and of course how torque varies with the different gearing ratios, higher speed less torque etc, nothing controversial or debatable I would say. If you google 'power loss through a bicycle chain' you should get many different sources of information. That's not to say the figures I've given are exactly right it was a guesstimate based on what I've read previously of about 3% loss but a slightly greater loss with an ebike but whatever there is always a fairly significant loss of power through a chain. I always try to be fair and unbiased in what I write. It's also worth pointing out that chains become less efficient as they wear and mid-drive motors cause far more rapid chain wear so its quite likely they will typically be at a higher wear rate on the chain which is why its claimed there is more power loss through the chain with a mid-drive motor unless its some other reason, i.e. two different sources of power acting on the same chain which might make power delivery through the chain more erratic and less smooth.

Bonzo Banana
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Re: Effort or Speed?

Postby Bonzo Banana » 3 Jul 2020, 8:24am

stodd wrote:
Bonzo Banana wrote:Also Suntour do a hub motor system with a torque sensor so senses rider power just like most mid-drive motors.
...
but sadly they are the most complicated motors too which means more reliability and service issues than hub motors generally.


It does seem that hub drives have better reliability overall than crank drives as you say. The Suntour system however is one of the least reliable systems out there judging by the number of complaints on the Pedalecs forum. Woosh (https://wooshbikes.co.uk/?tskit) is probably a better example of torque drive hub kits.


The Suntour system seems to have issues with its electrical sensors and while a fault is a fault, the issues don't seem to be related to the hub motor itself rather Suntour's own electrical system with torque sensor. I believe Suntour buys in the hub motors from another manufacturer and the failing is with Suntour's own minor components. Halfords have 20-25% of the UK bike market by value of which I think 11% of was quoted as ebike sales so a very large slice of the ebike market, they also do a huge range of Carrera ebikes most around £1000. My point is its very easy to simply compare the reliability of ebikes biased on what appears in forums but high end mid-drive motor bikes make up a tiny percentage of the ebike market compared to hub motors and Halfords ebikes are sold in huge volume compared to other brands. I mean if there was 25 Carrera ebikes sold for every Bosch equipped mid-drive ebike how do you factor that into forum postings? If I ran a company that only sold 100 ebikes a year and no issues for those ebikes were ever mentioned in forums you could falsely assume they were reliable ebikes compared to a company that sold 300,000 ebikes a year and was regularly mentioned in forums. There is a chap on youtube who uses his Carrera Crossfire for food deliveries. He is using it for hundreds of miles per week and has used it for many months possibly years without reported issues. In one of his videos he stops to talk to another food courier using an identical bike and both are stating how brilliant the bikes are.

https://www.youtube.com/watch?v=1nCgRovgyAo

I have to say I'm not keen on the Crossfire myself, I hate bikes like that with overly heavy front suspension much preferring the Carrera Subway ebike.

Technoblurb
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Re: Effort or Speed?

Postby Technoblurb » 25 Jul 2020, 7:30am

My. Wife has an E-bike which has give her a new lease of life, she has a muscular disorder which had stopped us cycling and hill walking. In most cases she actually has the power turned off, even on hill climbs. In this case she is actually pushing 23kg of bike, definitely not gliding up the hills. What it gives her is two things, the security that when her muscles give out at the brow of a hill, she will not fall off and that we can actually get home if needed. Cycling cannot just be for the hard core fitness types it is to get from A to B regardless of your limitation and get fit in the process. She still has to put the power in, just does it within her limitation and is getting plenty of cardio exercise in the process.

Oldjohnw
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Re: Effort or Speed?

Postby Oldjohnw » 25 Jul 2020, 8:19am

Technoblurb wrote:My. Wife has an E-bike which has give her a new lease of life, she has a muscular disorder which had stopped us cycling and hill walking. In most cases she actually has the power turned off, even on hill climbs. In this case she is actually pushing 23kg of bike, definitely not gliding up the hills. What it gives her is two things, the security that when her muscles give out at the brow of a hill, she will not fall off and that we can actually get home if needed. Cycling cannot just be for the hard core fitness types it is to get from A to B regardless of your limitation and get fit in the process. She still has to put the power in, just does it within her limitation and is getting plenty of cardio exercise in the process.


Sounds about right. Certainly my experience.
Last edited by Oldjohnw on 25 Jul 2020, 9:14am, edited 1 time in total.
John

Jdsk
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Re: Effort or Speed?

Postby Jdsk » 25 Jul 2020, 9:10am

Technoblurb wrote:My. Wife has an E-bike which has give her a new lease of life, she has a muscular disorder which had stopped us cycling and hill walking. In most cases she actually has the power turned off, even on hill climbs. In this case she is actually pushing 23kg of bike, definitely not gliding up the hills. What it gives her is two things, the security that when her muscles give out at the brow of a hill, she will not fall off and that we can actually get home if needed. Cycling cannot just be for the hard core fitness types it is to get from A to B regardless of your limitation and get fit in the process. She still has to put the power in, just does it within her limitation and is getting plenty of cardio exercise in the process.

Great to hear another example of the technology allowing someone to do something that is so beneficial.

Jonathan

nez
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Re: Effort or Speed?

Postby nez » 25 Jul 2020, 2:37pm

One way of making quick progress at least on a bosch e-bike is to keep the turbo (or sport or tour) on but pedal faster than the cut out speed on the flat. So my Koga cuts out electric power at 26 kph. That means I'm falling back on power for climbs but and doing nearly all of the rest of the work myself. Temperature and heart rate at the end of the ride seem to suggest it represents a good work out!

swscotland bentrider
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Re: Effort or Speed?

Postby swscotland bentrider » 30 Jul 2020, 1:50pm

I have little experience of e bikes and what I say reflects my brothers experience. He started to suffer a health problem that meant he had to keep his heart rate below a certain threshold. He lives in Somerset in hilly country. It looked like he was going to have to stop cycling. :(

He bought a Giant e bike. A carbon forked hybrid style bike with a BB style motor. He says that it enables him to ride hills below threshold but still gets back feeling as though he has had a good workout. Apart from the hills he doesn't much rely on the motor and consumption is quite low.

He is still singing its praises a year and 2500 miles in. :D

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bikes4two
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Re: Effort or Speed?

Postby bikes4two » 3 Aug 2020, 3:19pm

The electric cyclists come along and gracefully crest the hill.
No effort, no heavy breathing, no changing gears to speak of, and effortless and simple.


That (now) sounds like my sort of cycling, especially since succumbing to ill health of late.

It does seem that some who are fortunate enough to still peddle for all their worth, break into a sweat, climb big hills etc etc, have pedantic issues about ebikes.

They really must try and get over their inhibitions and see that there are many aspects to cycling enjoyment other than ........ well, you don't need me to say anymore I'm sure.
Without my stoker, every trip would only be half a journey

reohn2
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Re: Effort or Speed?

Postby reohn2 » 3 Aug 2020, 6:09pm

bikes4two wrote:......They really must try and get over their inhibitions and see that there are many aspects to cycling enjoyment........

Quite!
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Jdsk
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Re: Effort or Speed?

Postby Jdsk » 3 Aug 2020, 6:39pm

swscotland bentrider wrote:I have little experience of e bikes and what I say reflects my brothers experience. He started to suffer a health problem that meant he had to keep his heart rate below a certain threshold. He lives in Somerset in hilly country. It looked like he was going to have to stop cycling. :(

He bought a Giant e bike. A carbon forked hybrid style bike with a BB style motor. He says that it enables him to ride hills below threshold but still gets back feeling as though he has had a good workout. Apart from the hills he doesn't much rely on the motor and consumption is quite low.

He is still singing its praises a year and 2500 miles in. :D

As before: great to hear that the technology allows him the pleasure and health benefits of cycling.

Jonathan

mattsccm
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Re: Effort or Speed?

Postby mattsccm » 4 Aug 2020, 5:46pm

Random thought.
I wonder if a partial reason for most ebikes being of the MTB disposition is that as a road bike they have a more noticeable weakness, mentioned to me by several owners. Above that 15mph limit you are on your own and also with a heavier bike. Thats not overly fast on the flat for road riders and thus a possible limitation. You may be slower than your mates for much of the time. Chuck in the fact that likely owners are probably not the fittest out there and this issue is somewhat emphasised.
Not the only reason of course but I bet there are many that add up to this .

reohn2
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Re: Effort or Speed?

Postby reohn2 » 4 Aug 2020, 6:16pm

mattsccm wrote:Random thought.
I wonder if a partial reason for most ebikes being of the MTB disposition is that as a road bike they have a more noticeable weakness, mentioned to me by several owners. Above that 15mph limit you are on your own and also with a heavier bike. Thats not overly fast on the flat for road riders and thus a possible limitation. You may be slower than your mates for much of the time. Chuck in the fact that likely owners are probably not the fittest out there and this issue is somewhat emphasised.
Not the only reason of course but I bet there are many that add up to this .

I'd agree,though it only equates to groups or individual riders who can keep up an average of 15.5mph on the flat.
It's the hills that are the problem for most.
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Mick F
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Re: Effort or Speed?

Postby Mick F » 4 Aug 2020, 7:25pm

............ but for me, it's the hills that make cycling interesting and worthwhile.

eBikes make the world flat.
Mick F. Cornwall

reohn2
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Re: Effort or Speed?

Postby reohn2 » 4 Aug 2020, 7:32pm

Mick F wrote:............ but for me, it's the hills that make cycling interesting and worthwhile.

eBikes make the world flat.

And for me too,but don't kid yourself in thinking e-bikes make the world flat.They don't.
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Lodge
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Re: Effort or Speed?

Postby Lodge » 4 Aug 2020, 11:28pm

eBikes make the world flat.


Please see this afternoon's short workout. E-cycles don't make the world flat. I got a good workout with over an hour at >70% heart rate max even using boost mode and using almost an entire 500 Wh battery. Mind you it was an experiment to ascertain what the motor was capable of. Greater than 3000 feet of climbing in 17 miles at an average of 15.3 mph on a 30 kg trike with 8 kg luggage and 62 kg of me was going some. No issues with the motor. Not so sure about me though. And certainly not as boring as it would have been at 2-3 mph crawling up those hills without the motor.

That said I fully agree that
it's the hills that make cycling interesting and worthwhile.

The hills of the Staffordshire Moorlands where I am most fortunate to live are stunning.

20200804 Winkhill workout.png