Tonaro and Momentum reviews in new A to B issue 92

[Geebee]

Why do people insist of saying the drive train will suffer? if a bike is built for a remotely serious rider you are looking at a continuous output well above 300w and short peaks at up to 1 kw.

 

[GaRRy]

Why do people insist of saying the drive train will suffer? if a bike is built for a remotely serious rider you are looking at a continuous output well above 300w and short peaks at up to 1 kw.

But surely that is on top of what the motor can produce ?. Not saying it can/will happen but if the drive train is only designed for maximum a human alone can produce then a human + motor could over load it.

 

[Geebee]

Yes but I assume most e bike riders aren't putting out that level of power without assistance, I know if I was still putting out what I used to I would not be riding an ebike as I was a lot faster and had longer range without the e-assist.
Don't get me wrong I still played with E-bikes as I love them but when VERY fit and healthy they were a handicap not an assistance.

 

[GaRRy]

Yes but I assume most e bike riders aren't putting out that level of power without assistance, I know if I was still putting out what I used to I would not be riding an ebike as I was a lot faster and had longer range without the e-assist.

BIG Assumption. Would agree probably true for a lot but not all.

eg what about those buying to make it easier to go to work etc who also use normal bikes for recreation so still capable of putting down full power or a die hard mountain biker looking for a bit of assistance up hills as thats the boring bit ?

As I said not saying it will happen and would not appear to be a major issue but certainly possible

 

[RobF]

Not much evidence of this at all , I had the 24V Panasonic Centre drive for 3 years with derailleur and had no problem whatsoever, I feel sure there would have been an outcry from others posting about broken chains on this forum if that had been the case. Where there has been some discussion and doubt actually from some of the manufacturers like Shimano is whether or not their hub gears are completely compatible with the latest more powerful centre drives.

Alan

Plenty of evidence of noisy gear changes with crank drive bikes.

Extra noise = extra wear.

 

[RoadieRoger]

Obviously these bike designers aren`t getting it .In early Engineering training I was led to believe that a shock load was twice the normal load .This must apply to chains as well .

 

[flecc]

Obviously these bike designers aren`t getting it .In early Engineering training I was led to believe that a shock load was twice the normal load .This must apply to chains as well .

There us an instance of chains suffering with crank drive in the Bosch unit. When first introduced there were reports in Germany of chains being wrecked in about three months due to the unit's power. Since this problem subsequently disappeared it's assumed they detuned it slightly after early production.

Other than that the only reported transmission problem specific to crank drives on production bikes was with the original version of the Giant Lafree Comfort model which used the generally rather poor Shimano 4 speed hub gear. A number of these failed and Shimano withdrew that gear hub and have never replaced it, Giant using the tough SRAM P5 five speed hub instead for the Comfort model and the Nexus 3 and SRAM S7 on other Lafree versions. Since that problem was specific to one gear hub design only, it cannot be blamed on the Panasonic crank drive fitted to the Lafree series.

 

[10mph]

Just received the latest issue 92 of A to B magazine, which has reviews of two new simply specified Chinese made e-bikes under the Momentum brand. They have some interesting features and A to B are clearly impressed.

The Tonaro review is of the Eagle model and it is distinctly critical in a number of ways, bike weight, battery weight, battery warranty, power control, gear and chain problems and range being singled out in particular for criticism.

I have to say that, as ever, I differ quite strongly from many of the views they express, especially on the Momentum bikes. The issue 92 hasn't reached the free-to-read online website yet, but should do so shortly.

I got an email yesterday to say the free-to-read issue 92 of A to B was available - you just register to access it.

I was amused read in the review this characterisation of the Tonaro Eagle and its riders,

As these machines are aimed firmly at lazy folk, and market research indicates that people of this kind don’t even like to turn pedals, let alone apply any force, there is also a twistgrip, which delivers power on demand.

Despite my increasing appreciation of the availability higher assist settings on my Agattu, and indeed my more frequent use of them, I hate the electric moped like feel of the crudely controlled Tonaro type of bike. I would always choose a Panasonic or similar motor with the motor power controlled by means of a proportional torque measuring device.

 

[jerrysimon]

Lazy folk!

Many people use e-assist bikes when the alternative given their physical condition, means that they would never even consider using a bicycle.

I myself am an insulin dependant diabetic and without e-assist, there is no way I would have ever considered commuting daily the 10 mile round trip via a bicycle.

The use of these kinds of words/statements do little to promote ebikes to the public

Jerry

 

[Old_Dave]

When first introduced there were reports in Germany of chains being wrecked in about three months due to the unit's power. Since this problem subsequently disappeared it's assumed they detuned it slightly after early production.

Or fitted a 'better' quality chain..

 

[Jimod]

I hate the electric moped like feel of the crudely controlled Tonaro type of bike. I would always choose a Panasonic or similar motor with the motor power controlled by means of a proportional torque measuring device.

Where as I much prefer the system on my bike which means that as long as I'm turning the pedals the motor gives me full power. I don't see the point in the bike deciding for me how much power it will give me.

If I decide I want to go slower I can always adjust the PAS setting. Torque sensors are not for me.

 

[indalo]

I hate the electric moped like feel of the crudely controlled Tonaro type of bike. I would always choose a Panasonic or similar motor with the motor power controlled by means of a proportional torque measuring device.

You'll get no argument from me on that score sir! Torque sensors are not unique to crank-driven bikes of course and I was pleasantly surprised by how well the power delivery operates on some hub-motor bikes I rode not long ago.

Nonetheless, I still have a preference for crank-drive and I think Bosch have it about right, especially on those bikes where the manufacturer has placed the battery inside the the triangle. The extended wheelbase to accommodate a battery behind the seatpost just seems so unnecessary to me and I don't care for those mounted on the rear rack either.

Indalo

 

[Patrick]

Despite my increasing appreciation of the availability higher assist settings on my Agattu, and indeed my more frequent use of them, I hate the electric moped like feel of the crudely controlled Tonaro type of bike. I would always choose a Panasonic or similar motor with the motor power controlled by means of a proportional torque measuring device.

I like the simple throttle control on my Powabyke X6. Although it does have a moped feel if you're letting the motor do most of the work you can also use it as a subtle (or not so subtle) top-up to your own efforts. If I'm pedaling hard then normally it's because I'm pushing myself so I don't want much assistance, so the assistance I want isn't proportion to the torque of the pedals.

With the throttle I can unconsciously adjust the level of assistance to match the way I'm feeling at that moment, for example I might start a hill trying to see if I can climb it on my own, then part way up realise that the answer is "no" and use the throttle to get just enough help to keep the challenge within my reach.

 

[flecc]

The extended wheelbase to accommodate a battery behind the seatpost just seems so unnecessary to me .

Indalo

It does have the advantage of better integration of battery and unit though, with no flying power lead to get damaged and exposed cable connections to suffer water damage. From that point of view Bosch have stepped backwards, and have also made provision for step-through impossible with that battery placing.

I don't think the tiny length increase of the rear of seat tube battery makes any material difference on a road bike, especially since most designs tweak the frame angles to minimise the additional length.

 

[10mph]

...
With the throttle I can unconsciously adjust the level of assistance to match the way I'm feeling at that moment, for example I might start a hill trying to see if I can climb it on my own, then part way up realise that the answer is "no" and use the throttle to get just enough help to keep the challenge within my reach.

I did not like the range of throttle controlled bikes which I tried out earlier this year. (see http://www.pedelecs.co.uk/forum/electric-bicycles/11816-redbridge-testing-hubs-v-cranks.html#post141596 ). Some throttles were extremely crude, and I then wrote,

I am not a fan of having one hand clasped to a throttle as seemed needed on some of the hub motor systems without a proportional torque sensing control - but that is a criticism of the control system rather than the hub motor as such. I like to be able to give prolonged signals with either arm. Also I did not like the way some of the hub control system carried on pushing for about a second after the the throttle was released- but I suppose you might learn to live with that.

So what happens with my Kalkhoff Agattu, with the proportional torque control, when I hit one of the hills which you describe? I often ride on minimum assist - I provide 2/3 of the power, and the motor provides 1/3. That way I get some good quality exercise taking into consideration my age and fitness. When the slope increases and I realise that I will soon start to slow, with my left thumb I can give the assistance-increase button either one press (which gives 1/2 power from me and 1/2 from the motor) or two presses (which gives 1/3 power from me and 2/3 from the motor). That is up to a fourfold increase in motor power if my power remains constant, and this can get me up all but the steepest of hills without increase of my effort. Actually if the hill is not too long I may also increase my own pedalling power, because I can look forward to some recovery after cresting the summit.

 

[indalo]

It does have the advantage of better integration of battery and unit though, with no flying power lead to get damaged and exposed cable connections to suffer water damage. From that point of view Bosch have stepped backwards, and have also made provision for step-through impossible with that battery placing.

I don't think the tiny length increase of the rear of seat tube battery makes any material difference on a road bike, especially since most designs tweak the frame angles to minimise the additional length.

I have to take issue Flecc. While I agree that positioning a battery on the forward downtube creates a difficulty with regard to a step-thru facility, it does not preclude those who wish to enjoy Bosch power from so doing. It simply means a rack-mounted battery is required as on AVE and Hercules models for example.

In respect of the increased wheelbase, that varies from make to make. The effect on me is that my Gazelle simply does not fit my motorhome bike rack whereas my Cannondale fits perfectly. In the case of the Gazelle, it's too heavy anyway, even minus the battery. Both my MTBs and my Dawes road bike also fit the rack easily.

Any Bosch-powered bike coming in at 20Kgs or under with central battery placement would suit me perfectly.

Indalo

 

[flecc]

I have to take issue Flecc. While I agree that positioning a battery on the forward downtube creates a difficulty with regard to a step-thru facility, it does not preclude those who wish to enjoy Bosch power from so doing. It simply means a rack-mounted battery is required as on AVE and Hercules models for example.

Indalo

I did take that into account though, saying "with that battery placing". I was aware of the rack mounted batteries on their step-throughs, but that makes the system even less integrated and more vulnerable to water/connection problems.

I agree that the rear of seat tube battery isn't suitable for e-bikes intended to be carried behind narrower vehicles, nor is it as suitable for very rough off-road terrain where the wheelbase length is more critical. But the vast majority of e-bikes are never subject to either of those and for that majority I think the integrated low-mounted rear of seat tube battery makes a lot of sense.

 

[Deleted member 4366]

So what happens with my Kalkhoff Agattu, with the proportional torque control, when I hit one of the hills which you describe? I often ride on minimum assist - I provide 2/3 of the power, and the motor provides 1/3. That way I get some good quality exercise taking into consideration my age and fitness. When the slope increases and I realise that I will soon start to slow, with my left thumb I can give the assistance-increase button either one press (which gives 1/2 power from me and 1/2 from the motor) or two presses (which gives 1/3 power from me and 2/3 from the motor). That is up to a fourfold increase in motor power if my power remains constant, and this can get me up all but the steepest of hills without increase of my effort. Actually if the hill is not too long I may also increase my own pedalling power, because I can look forward to some recovery after cresting the summit.

.... but you get that surging instead when you press hard on the pedal going up hills, which as well as being a bit uncomfortable, is also a bit inneficient and you have to stop if your legs get tired and can't pedal any more.. Every system has advantages and disadvantages. I've not yet found one that I couldn't get on with. The 36v Panasonic scared me when it clunked as I put my foot on tyhe pedal, but that was because I wasn't expecting it. I guess you soon get used to any idiosycrasies, when you own a bike.

 

[eddieo]

the Panasonic "clunk" is always being discussed on German pedelec

 

[Kenny]

I've no doubt that the Bosch has a smoother power delivery and is probably a more torque system. Having had years to study the Panasonic drive I should hope they'd have improved on it.

That said I wouldn't like folk to think that the Panasonic system is in any way agricultural. Occasionally during slow hill climbing you can feel a faint pulsing and if you put a lot of pressure on the pedal at a standstill it will try to pull away.

These are minor issues however and the general ride quality of my Pro Connect is great. After 2500 miles I'm more than happy with the bike, well balanced and reassuring at any speed and the latest batteries have a great range.

Couldn't imagine anyone not enjoying the ride.