Cadence and finding the 'sweet spot'

Danny-K

Esteemed Pedelecer
Aug 25, 2008
281
0
South West
Since first signing up to this forum I can remember reading Flecc's appraisal of the Kalkhoff's and his view that if the rider wishes to get the best support from the Panasonic motor, then just relax and pedal more slowly thus fooling the motor into judging that you need more assistance.

Thus, when I first became acquainted with my particular bike I thought the motor would behave similar to the delivery cycle of the Panasonic's; ie., pedal at a lower cadence to gain more from the motor. I quickly discovered this didn't work on my bike, (nor should it, it's not a Panasonic), and when on the smaller cogs using a low cadence was hard work. My bike, (The Salisbury), rewards higher cadences, and gives it best, (for me anyway), with the three largest, easier, 'hill climbing' sprockets - but not when on a severe hill - but for everyday use.

Pedalling along, (no throttle - pedelec only mode), in a cog about one or two less than I actually need appears to deliver 12-to-15 mph speed and 'free' propulsion, (can't be sure of the true speed as I had to send the faulty cycle computer back that I recently bought), with the motor appearing to do all the work, and is very enjoyable when I just relax and drift into saunter mode - truly blissful propulsion. My cadence is quite swift and seems to suit and engage the motor, but not the type of swift cadence that is redolent with rider effort, as my pedalling is just 'going through the motions' with what feels to me like 'nil' input, with just the slightest hint of resistance to stop my legs flailing wildly and becoming uncomfortable. Inevitably the road levels out or drops and when then happens I am 'forced' to select a smaller cog, and higher speed. But here's the rub - it's less enjoyable as regards rider effort. I can feel stronger resistance and I know I've been out cycling. At the moment I'm experimenting with trying to use the three largest sprockets only, (freewheeling when things gets easier), just to stay within that sweet spot.

Tonight about 8:00pm was a case in point. I'd nothing in the fridge and decided to cycle to the late night shopping centre 2 miles away, floodlit lighting in the huge parking areas, security guards, and security cameras, so felt safe about leaving the bike unattended; locking the Salisbury into one of the bicycle pens.

Using the second and third easiest sprockets to ride there, but not the large, 'granny sprocket', it was just perfect. Using shared cycle-paths all the way as I dislike night riding on the road, it gave me a chance to test out my new rear light and feeling a bit 'meh' I didn't want to exert myself in the slightest. And I didn't - the bike just floated along the two miles, total bliss. By the time I'd done my shopping and ready for the return trip I was now 'pepped up' and ready for some cycling effort, but I refrained and stayed within my new sprocket and cadence set-up and again floated back to base effortlessly. A lot of cyclists think that a high cadence means you'll end up tired out pretty quickly, but done correctly it does the opposite; actually preserves your energy and protects your knees from injury.

I wonder how many others cycle to stay within their 'sweet spot', whatever the characteristics of their particular motor, or let the competitiveness of the traffic drive them on to ever higher personal speed records, (and I suppose higher fitness levels). Me? I enjoy armchair cycling.

P.S. Here's the rear light I fitted to the pannier rack. If you have a carrier with a rear plate like the Salisbury has, you can fit one of these instead of trying to fit the typical rear light that has a seatpost/seatstay only kind of fitting. And the best bit is - it's only £3.99 post free! And with batteries INCLUDED; (from Chain Reaction Cycles only) -



P.P.S. The locking screw at the bottom of the light is needless 'belts and braces' as the plastic red outer snaps on and off securely like a lot of lights, and would stay firmly locked in place without the screw. Not complaining; just saying.
 
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the_killjoy

Esteemed Pedelecer
May 26, 2008
822
226
For the wisper, it certainly seems that on a slope dropping a gear and upping the cadence puts me in the sweet spot.
 

Barnowl

Esteemed Pedelecer
Sep 18, 2008
954
1
Yes when I first had my bike I spent most the time in the highest couple of gears. It was another thread where I think it was Flecc who recommended a cadence of 60 - 70 cycles. I tried this and found it was much more comfortable. It's definately easier on my knees as well. My most enjoyable ride to date was on Sunday monday. It was sunny, cool, and not windy. I stayed off the main roads. I forgot about the bike computer and just took it easy. Much of the time I was just freewheeling. The motor took the pain out of the uphill bits. An 18 mile round trip took only about 15 minutes longer but I enjoyed every minute of it. Speed ain't everything.:)
 

Mussels

Esteemed Pedelecer
Jun 17, 2008
3,207
8
Crowborough
I ride about 3 hours a day in 2 shifts and have found that high cadence is far better, even though I am unfit I can ride constantly and enjoy it. One of the best aids for this style of riding I have found is SPD pedals with cleats*, I first tried toe straps but they were a waste of time.
I do aim for speed and suprise myself by getting much the same buzz as I do on a motorbike, my next hurdle is reducing my aerodynamic drag as that's now stopping me going much faster. :)

* I've also dropped the chainwheel from 52 teeth to 36 teeth and discovered a vast improvement but that's a bit extreme to suit the steep hills I go up.
 

JamesC

Esteemed Pedelecer
Sep 1, 2007
435
5
Peterborough, UK
Danny

Finding the sweet spot is an excellent opener for a thread on ebiking. There is certainly that moment when the work is neatly divided between the rider and the motor, which is what has encouraged many of us to get great pleasure from cycling.

Certainly, the independent control of a hub motor with throttle allows greater freedom to allow the legs to find a good cadence - change down a gear to reduce the load and spin a little faster.

The panasonic chain drive senses that the cadence has slowed and inputs some help to enable a faster leg speed, and then invites the rider to repeat the process by changing to a higher gear.

I find the software works well when speed is increasing, and also works well when the going is very tough on a steep hill.

But it is sometimes harder to choose the right gear (and find the sweet spot) when a gentle slope suggests it might be good to drop down a gear. The result is a little uncertain - the software seeing a faster leg speed and withdrawing assistance until the rider slows further.

Riding the Torq (hub motor), the sweet spot for me is nearer 70 RPM and on the panasonic ProConnect it is slower at 60 RPM.

I gather that these cadences are below the optimum for troublefree knees, but then ebiking is about sharing the load with the motor and alleviating the pressure on the joints.

Is that a fair assessment ?

James
 

Barnowl

Esteemed Pedelecer
Sep 18, 2008
954
1
85 RPM on the flat is recommended to avoid a certain type of knee problem (ITB friction syndrome) with minimal effort up the hills. How you can measure RPM without cadence on your bike computer is a mystery to me.
 

JamesC

Esteemed Pedelecer
Sep 1, 2007
435
5
Peterborough, UK
85 RPM on the flat is recommended to avoid a certain type of knee problem (ITB friction syndrome) with minimal effort up the hills. How you can measure RPM without cadence on your bike computer is a mystery to me.
Now and then, I glance at my watch which has a big second hand. Only takes a minute to count the leg speed.

I am definitely not advocating my leg speed as good - just happens to be what I can manage.

In my opinion, the panasonic drives could afford to offer assistance in their software at a slightly higher cadence (maybe 10 RPM higher).

You recommend 85 RPM which is non-assisted on a panasonic drive. My natural inclination is to sink back until I am just working at the top end of the assistance.

James
 

flecc

Member
Oct 25, 2006
52,763
30,349
Riding the Torq (hub motor), the sweet spot for me is nearer 70 RPM and on the panasonic ProConnect it is slower at 60 RPM.

I gather that these cadences are below the optimum for troublefree knees, but then ebiking is about sharing the load with the motor and alleviating the pressure on the joints.

Is that a fair assessment ?

James
I think that's a fair assessment James. Keeping up a reasonable high cadence when climbng steep hills is probably more important on hub-motor bikes since they are poorer when reduced to low speeds when there might be a temptation to slog on the pedals.

The Panasonic system's need for lower cadences for power to be available isn't so critical for the knees when a suitable gear can be chosen for a slower climb with less effort from the rider, though I agree that cadence could be set a little higher with advantage.
.
 

Danny-K

Esteemed Pedelecer
Aug 25, 2008
281
0
South West
Cadence

Finding the sweet spot is an excellent opener for a thread on ebiking.
Arrgggh... Had to type this out again from memory, clicked submit post, and hadn't signed-in. Oh dear here goes again then, think this is what I meant to say -

Thanks James. I've been that occupied with longer seat-posts and finding a comfortable position on my recently acquired one-frame size e-bike that its only in recent days that I've applied myself to finding the optimum cadence comfort and speed mix for my particular motor.

Whilst its true that a high cadence is more efficient, conserving energy and overcoming the 'dead spot', (and kinder on the knees), a low cadence is anything but that. Most of all, it applies in principle to those riders on regular pushbikes. Therefore in this instance your Panasonic motor, by offering assistance at low cadences, may actually alleviate what the low-cadence pushbike rider would otherwise have to endure - higher stress levels on the knees at low cadences from pushing a high gear without the luxury of motor assistance.

Which begs the question; for motor assisted bikes, what is an efficient cadence?

On the flat, most riders would be better off training themselves in trying to achieve a cadence of 75rpm, (count your pedal revolutions for 15 seconds then simply multiply by 4) - 75rpm being considered a suitable high cadence achievable by all for efficient and effective cycling. It's the cadence I'm most comfortable at, (typical touring-riders cadence). Novices can often be seen using a low cadence of 50rpm. I find that trying for a racing cadence of 100rpm and over, almost impossible with feet flapping wildly out of control.

As we age our cadence naturally drops over time. And given that the typical e-biker is no spring chicken it's fair to say that I doubt if there are any really, really, high cadence riders within the forum membership.

However all that's from the regular push-biking world - and this is the parallel world of e-biking. So with motor assistance taking up much of the load, do those 'guidelines' apply? I think this e-biking world is so new and under-developed that no guidelines exist as they do for the push-biking world. So it's up to us, (if I can now go all poetic for a mo'), in this brave new world, to define them. Which is why I first posted, wondering what others found as the most comfortable for them and their particular motor.

Finally, guess which e-biking manual this came from:

"The essence of skillful cycling is to conserve energy. It is clearly inefficient to waste energy by rocking from side to side in an attempt to push a bigger gear. Keep your gears low and you will be able to sit more firmly in the saddle, allowing you to concentrate on turning the pedals smoothly."

Answer: None, (okay my little practical joke), It came from a book for pushbike enthusiasts whilst e-biking was in its infancy. It was published in 1980 - Could have been tailor-made for today's e-biking world, what with that opening sentence, don't you think?
 
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Tiberius

Esteemed Pedelecer
Nov 9, 2007
919
1
Somerset
I think this conversation shows why gears (rider gears, I mean) are so important on a e-bike.

The uninitiated would think that the motor does the work, so why are gears needed, but my experience is that the best enjoyment is to be had when both rider and motor are working together. To get that requires a good range of rider gears. I've only ridden a throttle control bike, but I imagine a similar principle applies to other systems.

In fact, there has possibly been more discussion on this forum about replacing chains and gears than about replacing motors. That's quite encouraging, really.

Nick
 

JamesC

Esteemed Pedelecer
Sep 1, 2007
435
5
Peterborough, UK
Which begs the question; for motor assisted bikes, what is an efficient cadence?
With ebikes, the "sweet spot" takes a little time to find - the point at which the rider is operating at a comfortable and effective leg speed, and the motor is also operating sweetly.

The beauty of the ebike is that extra assistance is provided when the rider workload increases; hubmotors find some extra torque when the bike's speed slows (operating within a specified speed range), and panasonic chain drives do the same when the rider's cadence slows.

For me, the panasonic gets a pluspoint because the software is capable of maintaining the rider's preferred cadence. Providing the bike is equipped with a wide enough gear range, then the bike can be used in any terrain at the most comfortable cadence.

The limitation at the moment is that one particular cadence has been chosen, and written into the software, and some riders would find it a little too slow.

So, we can find a good point of balance between the input of the rider and the motor (first stage of finding the "sweet spot"), but the final stage of being able to tune this spot to suit the particular quirks of the rider would put the icing on the cake.

It would be marvellous if we could select our preferred cadence; maybe 5 choices in steps of 5 RPM, say 60 through to 85.

This would fix our individual "sweet spot", with the software working to put us back into the groove across the whole of the gear range.


Is Panasonic a member of the forum ?

James
 

Barnowl

Esteemed Pedelecer
Sep 18, 2008
954
1
Now and then, I glance at my watch which has a big second hand. Only takes a minute to count the leg speed.

James
Thanks James. I never though of that - probably because I don't wear a watch and I'm long sighted to boot. Must get one with a big second hand.
 

JohnInStockie

Esteemed Pedelecer
Nov 10, 2006
1,048
1
Stockport, SK7
It would be marvellous if we could select our preferred cadence; maybe 5 choices in steps of 5 RPM, say 60 through to 85.

James
Just curious, but if we could alter the size of the front chain wheel, wouldnt that have an effect on the cadence that the motor wheel sees?

John
 

Mussels

Esteemed Pedelecer
Jun 17, 2008
3,207
8
Crowborough
Any reason for this? Wrong seat, wrong height of the seat, wrong inclination of the seat, wrong distance from the seat to the handlebars....., wrong rider, wrong what?
It happens to me because my shoes are tight, wearing cleats helps a lot as I can pull up on the shoe easing pressure points.
 

flecc

Member
Oct 25, 2006
52,763
30,349
It came from a book for pushbike enthusiasts whilst e-biking was in its infancy. It was published in 1980 -
In fact e-biking wasn't even in it's infancy then, since the world's first commercial e-bikes went on sale in 1991. In 1980 petrol two strokes were still the power source though production of add-on units had ceased some years before. The Velosolex was still in production for those who wanted motorised biking though.
.
 

Danny-K

Esteemed Pedelecer
Aug 25, 2008
281
0
South West
In fact e-biking wasn't even in it's infancy then, since the world's first commercial e-bikes went on sale in 1991. In 1980 petrol two strokes were still the power source though production of add-on units had ceased some years before. The Velosolex was still in production for those who wanted motorised biking though.
.
Didn't know that Flecc, 1991? Interesting.

As it happens when I first wrote that post I originally had typed something along the lines off, '...before e-bikes were even just a thought in some designer's head...' but deleted it as I thought someone's bound to know of a prototype e-bike in some part of the world at that time, so went for a safer catch-all. Still, could have sworn I read/saw adverts for e-bikes in the eighties.
 

flecc

Member
Oct 25, 2006
52,763
30,349
There were private experimenters before 1991, but nothing came of their efforts. Even from 1991 the commercial efforts were initially crude, one of them using a truck wiper motor as the drive.
.
 

Danny-K

Esteemed Pedelecer
Aug 25, 2008
281
0
South West
Any reason for this? Wrong seat, wrong height of the seat, wrong inclination of the seat, wrong distance from the seat to the handlebars....., wrong rider, wrong what?
An excellent link there Poppy from Barnowl. First off numb toes shows something is wrong and you have to get to the bottom of it. Back in the 70's and 80's I used toe clips and straps - it was de rigeur. But the metal clip at the front always dug into my toes, despite using the largest size available. At the end of a day's riding my feet were sore as hell. Later when I adopted the click-in clipless pedal idea, all my problems appeared solved, and that's the way it's been ever since - until e-biking. Just recently I've developed severe and crippling pains in my left heel and I've been diagnosed with plantar fasciitis. On examining the cleats on my cycling shoes it appears I've arranged them so that my feet are clipped-in straight ahead when in fact my feet naturally have a slight 'duck-like' outward 'ten-to-two' gait. Until I sort that out I haven't ridden those bikes. Which is why I became interested in e-bikes. Coincidently, the pedal on the e-bike is the open platform type, and all of a sudden I find it very comfortable. I'm planning to upgrade to the mountain-bike huge-type of platform pedal and fit them with the plastic half-size toe-clips to help with the upstrokes, which work well for me on my folder, the foot being free to find it's own angle. And here's the wonderful thing - since taking up e-biking with the 'novice' pedals the condition in my heel has improved considerably. A chiropodist tells me that exercise often improves/cures people with my condition, so the hours of pedalling have had a beneficial effect. I have my first hospital appointment at the end of November, (physiotherapy I think), I'll be annoyed if I have to report improved circumstances as I want the full medical 'Monty' applied to my condition, as I fear they might think I only suffer from it slightly. However, in my case it would appear, cycling, (pedalling), is actually curing my heel ailment.

Back to your ailment Poppy. Check out your position on your bike. For instance just a wild guess, but check the saddle is not set too high for you; are you rocking from side to side when pedalling? In other words: you can reach the pedals comfortably can't you? Another thing to check is that the seat is not pointing uncomfortably upwards. If you're not using toeclips or cleats of any kind then it almost certainly has to be the set position on your bike; starting with the saddle height and angle.