Number of Watts on Bosch ebike in Eco mode

[stuart1458]

Anyone know how many Watts of support are provided by a Bosch Performance CX in ECO mode? I cant find it in any of the tech specs.

 

[sjpt]

Depends how much you put in. It outputs a certain percentage of your input in each mode (torque sensing). Copied from https://electricbikesbrisbane.com.au/blogs/news/bosch-e-bike-systems-whats-new-2020 below; you will see it will give exactly 1/2 what you give in Eco mode (gen 2) or 60% (gen4)

 

[stuart1458]

Depends how much you put in. It outputs a certain percentage of your input in each mode (torque sensing). Copied from https://electricbikesbrisbane.com.au/blogs/news/bosch-e-bike-systems-whats-new-2020 below; you will see it will give exactly 1/2 what you give in Eco mode (gen 2) or 60% (gen4)

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Thanks. That is really helpful. I wonder how it works it out. I dont believe that it contains a power meter. They are way to expensive.

 

[sjpt]

There's a very course power meter on the right side of my Intuvia display (old basic Active Line motor).
Power meters are not that expensive, but maybe many would find them confusing? It would be much more helpful to have a more accurate remaining battery meter instead of the almost useless remaining range indicator.

 

[soundwave]

a external wattage meter wont work with bosch powerd bikes because the batt and the motor need to talk to each other to turn on and work so a meter whould brake that link and not even power on.

 

[stuart1458]

There's a very course power meter on the right side of my Intuvia display (old basic Active Line motor).
Power meters are not that expensive, but maybe many would find them confusing? It would be much more helpful to have a more accurate remaining battery meter instead of the almost useless remaining range indicator.

Mine is the gen4 CX but I dont think that makes any difference. Normal bike power meters use a strain gauge which is why they are so expensive and I dont believe they do that here. Having looked in to it I think they calculate torque using input power and dividing by the angular velocity (RPM). I agree with you about the range indicator. Calling it crap does crap a disservice.

 

[soundwave]

Mine is the gen4 CX but I dont think that makes any difference. Normal bike power meters use a strain gauge which is why they are so expensive and I dont believe they do that here. Having looked in to it I think they calculate torque using input power and dividing by the angular velocity (RPM). I agree with you about the range indicator. Calling it crap does crap a disservice.

that thing could not even tell the right time after a while and the purion display is the same can have 4 miles left with 4 bars on the batt display.

 

[Darren Hayward]

The range estimate is not useless but it does have a significant weakness. It needs to take account of how you've been riding the bike. If I ride to Wick the range estimate says I've ridden 7 miles with 35 miles left. After I then ride up Tog hill it the says I've gone 11 miles with 8 left. It gives much greater weight to how I've ridden the last few miles, which were all up hill. Once you realise that, it makes sense to some extent. But the most sense is in ignoring it.
Look at the 5 bars and the trip distance. I drop to 4 bars around the 10 mile mark. To 3 bars around the 19 mile mark, 2 bars around the 28 mile mark and to 1 bar around 36/37. I've gotten 43 out of my battery with 1 mile estimated range left (so the last bar gives less than the first 4). I don't know if it dies completely or goes into protected mode like my UCR30 after that as I've never taken it lower but my experience is that I can rely on 37 miles from the battery so I don't plan trips over that. It the trip distance that counts, ignore the rest.

Darren.

PS. The clock seems to lose about half a minute a month. Its no great hardship to reset it every few months but it would be nice if it was a bit more accurate.

PPS. I nearly bought a Nyon display but decided against it. If you really want power data the Nyon gives a breakdown of the watts from the motor and the rider. For the data hungry it might a good bet.

 

[sjpt]

I think they calculate torque using input power and dividing by the angular velocity (RPM).

Maybe, but in that case how do they measure input power? (I'm sure we agree it comes to the same thing from the rider's point of view).

The range estimate is not useless but it does have a significant weakness. It needs to take account of how you've been riding the bike.

PS. The clock seems to lose about half a minute a month. Its no great hardship to reset it every few months but it would be nice if it was a bit more accurate.

PPS. I nearly bought a Nyon display but decided against it. If you really want power data the Nyon gives a breakdown of the watts from the motor and the rider. For the data hungry it might a good bet.

The range estimate does take account of how you've been riding the bike (good), but only seems to use data from the last mile or so (just plain stupid).

I've never got round to setting my clock; perhaps I will some day. I'd buy a Nyon if it were under £20.

 

[GLJoe]

Normal bike power meters use a strain gauge which is why they are so expensive and I dont believe they do that here.

Since the bosch motors use torque sensing, they therefore must have a sensor which measures how much you are straining on the pedals. Therefore they must have a power meter.
And a strain gauge doesn't have to be expensive. It all depends on how accurate, repeatable, small and feature packed you want the final product to be.