Tonaro Esprit review, and buying without test riding

Geebee

Esteemed Pedelecer
Mar 26, 2010
1,256
227
Australia
I have had my Esprit for for 6/7 weeks now, so I though I might give my view on it.
First up I bought without the opportunity to test ride, this has turned out to be a good thing as if I had test rode it I would not have bought it.

It is a perfect fit as it is very adjustable, but the cadence that the motor runs at is way below my normal cadence and felt very "wrong", after a few rides I lowered my natural cadence and found longer rides not as tiring, then after several more long rides I found that spinning faster and not trying to run in higher gears so the assistance was trailing off offered an ideal pedal speed for me and reduced power consumption on the battery, this requires getting used to the feel/sound of the motor coming off load until it became automatic, this also means running a lower gear or 3 than the assist will allow.
If you hit a steep climb just let the cadence drop and the motor helps more, very counter intuitive to a spinner :)

Now re the AtoB review, I suspect in their testing they never fully adjusted to the bikes assist, Last night I rode 30 km mostly up the local mountain, the battery indicator rewarded me with the highest LED flickering off momentarily, the first time it has gone off since the initial ride (conditioning the battery), so how they got the short range they did has me stumped.

Next the chain breaking due to shifting whilst stopped (a no, no anyway), the cranks require 1 and 1/2 revolutions before the motor comes on so the derailleur would have sorted its self out short massive levels of abuse or pushing the throttle to full off the line.
Tapping the brake to shift is quick, simple and becomes automatic quickly, I can not understand how this did not occur to them as my first reaction to drive train noise on an assisted bike it to hit the brake to stop assistance to see where the sound is coming from.

My hub issue was incorrect torque on the wheel nuts and extreme abuse by myself, I have increased the torque and added a jubilee clip as a safety stop for when I feel like extreme off roading again :)

I do have the intermittent cut outs that some one else has mentioned previously as if the brake was hit but they are occasional, momentary and not really an issue.

The bike is climbs brilliantly and leaves my hub bikes for dead. If you had to get home with and injured knee or something as long as you could turn the pedals at all (mine doesn't have a throttle), the assist alone would make it up almost any hill.

At the price I paid for it I would buy it again in a heart beat.
 
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adifrank

Pedelecer
Apr 7, 2012
34
3
Canvey Island
Hi Geebee
Glad you like your Tonaro, i still haven't found the cause of the momentary motor cutting out on mine
even after thoroughly checking a the wiring.
But as you say it does not seem to be a problem, just odd.
However i am not happy with the battery on mine as after about three miles one light goes out on the power indicator, and after i rigged up a proper volt meter so i could monitor what was happening while riding it showed a 4 volt drop under load.

So in the spring i will get another battery but i don't know much about R/C batteries so will have to get
an alternative.

Maybe get some advice from all the knowledgeable guys on here as to the right type to get.
I think a 15 amp one would be more beneficial and allow me to go further afield.
your thoughts appreciated

Frank..
 

Geebee

Esteemed Pedelecer
Mar 26, 2010
1,256
227
Australia
I have made a LiPo battery as a range extender if needed with Hobby King batteries.
I will try that for a few rides and see if the hesitations go away.

Certainly sounds like you have a faulty battery, after the hilly 30 km ride above I was reading 38.6v on my meter which suggests I have a lot longer range available, and that ride had a huge amount of climbing in it.

I suspect a good 10 AH would cover most peoples needs but I would tend to go bigger depending on the cost per AH.
I have always DIY'ed my batteries so can't help with experience on whats good or not in the commercial ones.
 

adifrank

Pedelecer
Apr 7, 2012
34
3
Canvey Island
Hiya
I did find that the hesitation did not occur under load just when going along steadily and at all different
speeds.
Its pretty flat where i live and im down to38.0v after about 4 miles from full charge.
But the voltage sag under load seems excessive, i have only had the bike about 4 months and its been like it since new.
Not sure what type of lipo the battery is but im leaning towards a Lifpo4 at 15 amps.

Frank..
 
D

Deleted member 4366

Guest
However i am not happy with the battery on mine as after about three miles one light goes out on the power indicator, and after i rigged up a proper volt meter so i could monitor what was happening while riding it showed a 4 volt drop under load.
4v drop at 15 amps is not unusual for a 10aH li-ion battery. As long as you get normal range, there's nothing too worry about.
 

Jeremy

Esteemed Pedelecer
Oct 25, 2007
1,010
3
Salisbury
A 4V drop at 15A means that the battery internal resistance has risen to around 0.266 ohms

I don't know the cells or chemistry in the pack you have, but the very worst cells I know of for having a high internal resistance are the newer high capacity 18650 LiCoO2 cells. They are around 0.085 ohms per cell, so for a roughly 10Ah 36V nominal pack they would give a pack internal resistance of around 0.283 ohms, about what you're getting. It's unusual for these cells to be used in such a low capacity pack though, precisely because they have such a high internal resistance. When used in higher capacity packs the internal resistance, and hence voltage drop, reduces, and I've not yet seen these cells used successfully in packs of less than around 20Ah.

A 4V drop at 15A means that the battery is losing 60W as heat when it's delivering that current. This is a lot, as anyone who's touched an incandescent light bulb will know, and can't be good for the battery long term I'd have thought.

Even the really cheap low discharge rate RC LiCoO2 cells from Hobby King have a very much lower internal resistance, and hence voltage drop under load, than that. A 10Ah 10S pack made from cheap 15C RC type packs would have an internal resistance of around 0.01 to 0.02 ohms, so would give a voltage drop right at the battery terminals of around 0.15 to 0.3 V at 15A discharge.

For comparison, my ancient 10Ah 36V nominal Ping LiFePO4 pack has a voltage drop of around 1.5V at 15A, after around five years of use.