Torque and Rotation (Cadence) Sensing - Clarification Question

[Terry1100]

Hi All,

I posted here a few months ago when I was seriously in the hunt for a new Pedelec but (financial) circumstances got in the way.

I've been lurking ever since and keeping up with developments and given that my (not so) trusty Kawasaki is unlikely to make it through its next MOT I getting serious again.

I think that I would prefer a torque sensed bike (up to now I have only tested rotation sensed bikes). I have seen posts here that suggest that torque sensing is less suitable for lower levels of fitness as you need rider input before you get the benefit of assistance.

Can I check my understanding here - assuming I have the power setting at its highest, If I am completely knackered I will achieve top speed on the flat with a rotation sensed bike simply by twiddling the pedals

However, with a torque sensed bike I will need to be actively pedalling for the same top speed. But presumably, if I'm tired, with a torque sensed bike, I simply change to a lower gear - I will not be able to achieve the same road speed but won't I will be able to reduce my effort and let the motor pick up the slack - or have I missed something ?

In case the answer is different depending on whether the motor is driving the crank or the wheel, I am thinking particularly in respect of the Wisper 905 Torque which appears to tick most of my boxes.

 

[trex]

you will need to actively pedal for top speed, applicable to both crank drive and hub drive. Changing to max assist level is the only way to save your legs.

 

[Deleted member 4366]

It's not just the speed you have to worry about. It's hill-climbing too. If you can't press the pedal hard enough, your motor won't give full torque. On a long hill, you can get knackered, then it's a problem.

 

[Alan Quay]

Hi All,


However, with a torque sensed bike I will need to be actively pedalling for the same top speed. But presumably, if I'm tired, with a torque sensed bike, I simply change to a lower gear - I will not be able to achieve the same road speed but won't I will be able to reduce my effort and let the motor pick up the slack - or have I missed something ?

When you change to lower gear, your legs will generate less torque, so the bike will give less assistance, so you will go slower. When your speed drops sufficiently that your legs are once again generating more torque, the motor will assist more.

Torque sensored bikes are really aimed at the keen cyclist who wants it behave like a normal bike. If you are using it for utility purposes, I think you would want speed sensor and/or throttle.

The above scenario with speed sensor: Change to lower gear, pedals go around faster, more assistance, with less effort.

Of course, with a throttle you can do anything, when ever you like.

 

[JohnCade]

In practise with a TS if you are getting tired on a long hill after going at it too fast, then getting into a lower gear and turning the pedals without major effort will get you up it slowly. The motor should assist enough to do that with fairly low input from you. Rather like using a granny on a normal bike and cranking it up long hills slowly with little effort.

It depends if the OP wants to get fit at the same time as he commutes, as that should influence what he buys.

 

[trex]

woosh have a special offer at the moment. £599 for their Sport-TS until the end of the month.

http://wooshbikes.co.uk/?sport-ts

 

[oldtom]

If you can't press the pedal hard enough, your motor won't give full torque. On a long hill, you can get knackered, then it's a problem.

That's what cycling's all about surely?

If someone can't ride a bike because it's too taxing, electrical assistance helps considerably. If that still proves too difficult, then for a lot less money than high-end EAPCs, one of these does it all:



....or for a little more money:



.....or, if you'd rather avoid an IC engine, there's this:



Many people can ride any of these on their current licence but the requirements for those who can't aren't exactly onerous.

Tom

 

[torrent99]

Sigh.....

(Apologies to Messrs Cleese, Corbett & Barker)

Cyclist: (Dressed in lycra, SPDs & cycling helmet) I look down on him (indicates Pedelecer), because I'm a proper cyclist and he cheats.

Pedelecer: (Dressed in old school shorts & leather helmet) I look up to him (indicates Cyclist) because he is fit and strong, I look down on him (throttle biker) because he's weak and shouldn't be allowed on the road.

Throttle Biker: (Dressed in normal clothes) I know my place. I look up to them both, I wish I could do the things they can.

Cyclist: I am fit but haven't got any money. (kneels down) Although I always feel superior to him (Throttle biker), sometimes I'm jealous of him (Pedelecer) when I go up hills.

Pedelecer: I still lookup to him (cyclist), because although I have an expensive pedelec, I'm not as fit as I used to be. But I'm not as much a cripple as him (throttle biker) so I still look down on him.

Throttle Biker: I know my place. I'm not at all fit. I hope that the fitness Nazis don't discover how useless I am and make me ride a scooter with a helmet, insurance, hot uncomfortable protective clothing and difficulty parking. I haven't a hope of any kind of fitness on the scooter that those Pedelecers want me to buy. Perhaps I'd better stay at home. I know my place.

 

[Jimod]

Sigh.....

(Apologies to Messrs Cleese, Corbett & Barker)

Cyclist: (Dressed in lycra, SPDs & cycling helmet) I look down on him (indicates Pedelecer), because I'm a proper cyclist and he cheats.

Pedelecer: (Dressed in old school shorts & leather helmet) I look up to him (indicates Cyclist) because he is fit and strong, I look down on him (throttle biker) because he's weak and shouldn't be allowed on the road.

Throttle Biker: (Dressed in normal clothes) I know my place. I look up to them both, I wish I could do the things they can.

Cyclist: I am fit but haven't got any money. (kneels down) Although I always feel superior to him (Throttle biker), sometimes I'm jealous of him (Pedelecer) when I go up hills.

Pedelecer: I still lookup to him (cyclist), because although I have an expensive pedelec, I'm not as fit as I used to be. But I'm not as much a cripple as him (throttle biker) so I still look down on him.

Throttle Biker: I know my place. I'm not at all fit. I hope that the fitness Nazis don't discover how useless I am and make me ride a scooter with a helmet, insurance, hot uncomfortable protective clothing and difficulty parking. I haven't a hope of any kind of fitness on the scooter that those Pedelecers want me to buy. Perhaps I'd better stay at home. I know my place.

I like that. Sadly though, it won't have any effect on the saddo who appears to dislike disabled people on ebikes.

 

[Jimod]

Hi All,

I posted here a few months ago when I was seriously in the hunt for a new Pedelec but (financial) circumstances got in the way.

I.

I personally think a simple pedal sensor would be best for you, but only you can know. Try a few ebikes of both types and see how you get on.

My Kudos Typhoon has a pedal sensor so gives full power by simply turning the pedals. It would, if I wanted, carry me up a 7% slope with no effort from me. On steeper slopes though, you couldn't expect an ebike to go up with no effort from you but the pedal sensor will still give you full power to assist however much you can add.

Try a couple of bikes and see what suits you. You don't want to buy the wrong one and find it it isn't up to the job.

 

[Terry1100]

Thanks all for your answers - particularly John Cade who answered the question I actually asked (especially as I seem to have phrased it badly ).

I am fit enough to make the journey on a conventional bicycle - I did yesterday as an alternative to the Kawasaki but I average 11.5 Mph which is hardly likely to challenge Wiggo. Coming up Shoot Up HIll (in Cricklewood NW2) I was grinding a lowish gear - I'd just like to know that under these circumstances I'd be supported by the motor - even if the lower gearing prevented a high speed (or even made it up in a higher gear than I would have done without assistance).

I don't need an ebike to actually power me to work - it doesn't even need to get me there any quicker (although that would be a bonus) it just needs to make the ride easier - I'm not getting any younger and I do want to at least maintain or slightly improve my current level of fitness.

It all comes back to a need to actually ride a TS bike to make my own judgement.

 

[Chris the Sheep]

[edit: I was writing this while Terry posted the message above!!]

Hi Terry, allow me to confuse you even more!

While you say you're unfit, it isn't clear to me what you mean. For example there are lots of people who don't regard themselves as disabled but who maybe have a heart condition or trouble with their knees - and they might struggle with some torque-sensing bikes if it means they can't have an occasional rest or can't get the bike moving in the first place.

However, from looking at your original post you sound much like me - unfit but otherwise in good health. (I ride a Varadero 1000 by the way....). I did spend a few years mixing cycling and motorcycling as a way of getting to work but found the misery of a 10-mile headwind (and living in Blackpool I get that a lot) was putting me off. Yes I was fit but I was also exhausted when I got home.

I've owned two torque-sensing bikes and I can't compare them to a rotation sensor because I've never ridden one, but I think I can give you some reassurance that if indeed you are just out of condition a torque sensor would be fine.

That's not a recommendation by the way; you might simple prefer a rotation sensor and they tend to be cheaper too so it's your choice!

I liken riding with a torque sensor to a brisk walk; it does raise the heart rate a bit but is never exhausting. I've had both a hub-drive and crank-drive bike and even though both are torque sensing they have different strengths and some of those are down to the individual bike's design rather than being characteristics of the type.

For instance, the hub drive (Giant Twist) would respond quickly and strongly at low speed but needed more of my effort for hill climbing. The crank drive (using Shimano Steps) is designed to feed in power from a standing start so needs a decent push to get started (like a normal bike) but from then on is always giving strong assistance if you use the gears correctly.

If you're capable of riding a normal bike but just get knackered (i.e. like most adults) then you should be fine with a torque sensor and in my case I prefer a crank drive. But if you PREFER a rotation sensor then go ahead, it's entirely your choice - but do try both!

 

[Terry1100]

If you're capable of riding a normal bike but just get knackered

Got me in one

 

[JohnCade]

TS bikes are meant for cyclists who want to ride like cyclists but need or just want some extra power. Typically because either they are getting on a bit, and/or live in hilly areas. Or because they are bike unfit having not ridden for some time. They give the rider a bionic legs effect which is very satisfying, and by applying power and having it multiplied by up to three times by the motor you can go uphill faster than a pro roadie.

You say you have ridden speed or rotation sensor bikes and they don’t ride like that at all. They can be great fun but you don’t feel you are really pedalling them, and they don’t really ride like bicycles.

The best TS bikes tend to be German or Austrian, and for a commuter bike you could do a lot worse than a Kalkhoff Pro Connect 9. Currently with ten percent off at 50 Cycles and a bit over £1500.

 

[Cyclezee]

The best TS bikes tend to be German or Austrian, and for a commuter bike you could do a lot worse than a Kalkhoff Pro Connect 9. Currently with ten percent off at 50 Cycles and a bit over £1500.

An example of German bikes with TS for less than £1500,

Heinzmann eTR U £1495, Ceres eST £1395 and eTR-G also £1395​

 

[Terry1100]

Thanks - I'm concious that I wasted your time a bit earlier this year- but that third Heinzmann might fit the bill - it seems to be similarly specced to the Wisper 905 Torque

 

[oldtom]

An example of German bikes with TS for less than £1500,

Heinzmann eTR U £1495, Ceres eST £1395 and eTR-G also £1395​

These prices seem very reasonable to me compared to the mainstream competition. I'm not fond of battery on rear rack with a rear hub motor so the only one that interests me is the first model, the eTR U.

Hydraulic disc brakes and Heinzmann power should make for a strong bike on the road although I haven't ridden one.

If these models are anywhere close in performance to the Ezee-powered bikes, then they make a compelling case in my book.

Tom

 

[Cyclezee]

Thanks John - I'm concious that I wasted your time a bit earlier this year- but that third Heinzmann might fit the bill - it seems to be similarly specced to the Wisper 905 Torque

No worries Terry,

BTW, the Heinzmann is quite different in many areas to the Wisper.
You can see the full specification of the Heinzmann eTR models here on our website: http://cyclezee.com/pan-etr-hybrid-bikes.html

 

[Terry1100]

Is the only the battery position that is different between the eTR-U and eTR-G ?

 

[RobF]

Terry,

From your posts you want a torque sensor crank drive bike.

You don't mention budget, but a Raleigh Motus at about £2K might suit.

It's more widely available than many ebikes, so you might be able to track one down for a test ride.

I tried one and liked it, a mate has just bought one and is very pleased so far.

A couple of posters on here have spoken well of them.

Ideal commuter, down tube battery gives good balance and short cable runs make it more water resistant than some ebikes.

http://www.e-bikesdirect.co.uk/Item/Brands/Raleigh_Electric_Bikes/Raleigh_Motus_Crossbar_Electric_Bike.aspx