Bosch climbing speed

[soundwave]

the motors are programmed at bosch and atm there is no way to change them from active to performance.

you can buy motors but only in exchange for the motor you have.

id try a smaller sprocket

 

[Danidl]

hi all if indeed moters are all the same but software limited is there a (chip) in the moter or the software in the lcd?
there does not seem to be any bosch/dealer options to go from active to perfor seemance .
yesterday tried same hill Carrera with tdz cd drive I am not sure if mines 60nm or 80nm 250 watt though, sport mode 44front 3rd largest on rear bit of a run at it got up ok bit off an effort.
I believe my bosch bike has 18t front which I think equals 36t used rear 23 then 26 got up it but some effort rear is 11-34

.. where the intelligence is located in a Bosch system is not publicly known. There are multiple chips in the system, both in the battery, in the LCD display and in the motor unit. My assumption is that the LCD is primarily a communications and display unit and communicates back to the motor and the battery as required. The little up down thumb switch is part of the LCD .


I would question whether the motors are identical in all their parts, unless someone has stripped down motors and have listed all the stamped part numbers, I would take that assertion with a grain of salt. It may be so ..

From memory I think the Bosch rotates 2.5 times per crank rev , so an 18t front would be equivalent to a 2.5*18 or 45 t.

 

[soundwave]

i have 18t on my bike now the above is 25t and with that it would not climb anything with that on it

 

[KTM Bike Industries UK]

ive looked recently at cube and giant mtbs £2300-£2700 out of my price range but all seem to have powerfull moters 75-80nm
bosch active line 50nm bosch performance 63 bosch performance cx 75nm

I actually came to dead stop trying to go up a short steepish hill (50nm moter activeline)

This shouldn't happen, you have to learn how to ride them and get the best out of the motor. Cadance is crucial and keeping it high means you can spin up pretty much anything, way way faster than a normal bike. You just need to use the gear to help the motor do its work efficiently. You can't ride it like a normal bike and get the best power.

 

[footpump]

my cadence at 68 years old is lousy I tried it on the flat sport mode and could do 70 rpm for a short while. the intuvia display arrow quite often suggests I go
to a higher gear.
as soon as I hit a bit of a slope my cadence falls, (cannot keep the power up as my legs begin to ache, which is the reason I need an ebike)

 

[Danidl]

my cadence at 68 years old is lousy I tried it on the flat sport mode and could do 70 rpm for a short while. the intuvia display arrow quite often suggests I go
to a higher gear.
as soon as I hit a bit of a slope my cadence falls, (cannot keep the power up as my legs begin to ache, which is the reason I need an ebike)

Not many years behind you.. use whatever cadence suits you be it 40, 50 or 60 or whatever and make the gears do the work.. you know the turbo assist mode was designed for the likes of us., And it's just a thumb away.

 

[anotherkiwi]

The fastest ever non doped rider averaged 36.7 km/h up the Alp d'Huez stage (Pantani 38 km/h with the help of a little EPO). You probably couldn't average that speed on a Bosch powered bike with a dongle... The standard battery probably wouldn't make it to the top in those conditions.

Makes one think

 

[Woosh]

my cadence at 68 years old is lousy I tried it on the flat sport mode and could do 70 rpm for a short while.

it looks like you could use a throttle.

 

[footpump]

yes pantani was indeed amaxing whats epo I could do with more nm epo and a throttle

 

[Deleted member 4366]

my cadence at 68 years old is lousy I tried it on the flat sport mode and could do 70 rpm for a short while. the intuvia display arrow quite often suggests I go
to a higher gear.
as soon as I hit a bit of a slope my cadence falls, (cannot keep the power up as my legs begin to ache, which is the reason I need an ebike)

Torque multiplier systems are not suitable for some people. I can't understand why people on this forum keep recommending them to guys that have arthritis, weak legs or are otherwise not able to pedal hard. You'd be better off with something like a Wisper Torque or a Woosh.

This thread started by comparing an Ezee motor at 48v and 18 amps with a Bosch up a 20% hill. Unless the rider is substantially overweight and assuming the standard 250 rpm version, the Ezee will win hands down.

With a total weight of 100kg and about 100w of rider input, the Ezee bike will climb the hill at 9 mph without overheating, running at an efficiency of 70%. The load is about 600w and the motor will take 864w from the battery

The Bosch motors run at a max current of 18 amps at 36v (AFAWCT). At an optimistic efficiency of 70%, the most power the Bosch would produce 454w, so it only has 75% of the Ezee's power at that climbing speed.

The Ezee would still be able to climb the hill without pedalling. If the rider pedalled harder than 100w, both bikes would climb faster, but the Ezee would become more efficient and the power difference would increase, so the Bosch would never be able to catch it.

Most of what people are saying about how fast they can climb a 20% hill is just dreaming. To climb at 15 mph requires 1141W (100kg all-up weight). The most the Bosch can provide is about 518w, which would mean that the rider would have to provide 623w. That's what a fit person can do sprinting up stairs. I'm sure there are guys on the forum can do that for a short burst, but not the average forum reader will struggle to maintain 200w for any length of time.

Working back the other way, the Bosch at 18 amps, 36v and an efficiency of 80% (very optimistic), can produce 518W. Add 200w rider input, and let's ignore drive-train losses for now. that gives a net power of 718w, which can propel a 100kg all-up weight up a 20% hill at 7.9 mph.

I hope these facts and figures put some of these myths into perspective.

 

[Artstu]

You just need to use the gear to help the motor do its work efficiently. You can't ride it like a normal bike and get the best power.

Indeed, mine likes a lower cadence than I prefer to give the most power.

 

[Artstu]

The fastest ever non doped rider averaged 36.7 km/h up the Alp d'Huez stage (Pantani 38 km/h with the help of a little EPO). You probably couldn't average that speed on a Bosch powered bike with a dongle... The standard battery probably wouldn't make it to the top in those conditions.

Correction 22.58 km/h. No dongle required to beat that time, fairly sure on the right day I could beat that on my Bosch Classic.

http://www.climbing-records.com/2013/07/all-time-top-100-fastest-rides-on.html

 

[Deleted member 4366]

Indeed, mine likes a lower cadence than I prefer to give the most power.

As the cadence decreases, the torque from the motor increases, but so does your speed, so you end up with less power.

 

[Danidl]

Torque multiplier systems are not suitable for some people. I can't understand why people on this forum keep recommending them to guys that have arthritis, weak legs or are otherwise not able to pedal hard. You'd be better off with something like a Wisper Torque or a Woosh.

This thread started by comparing an Ezee motor at 48v and 18 amps with a Bosch up a 20% hill. Unless the rider is substantially overweight and assuming the standard 250 rpm version, the Ezee will win hands down.

With a total weight of 100kg and about 100w of rider input, the Ezee bike will climb the hill at 9 mph without overheating, running at an efficiency of 70%. The load is about 600w and the motor will take 864w from the battery

The Bosch motors run at a max current of 18 amps at 36v (AFAWCT). At an optimistic efficiency of 70%, the most power the Bosch would produce 454w, so it only has 75% of the Ezee's power at that climbing speed.

The Ezee would still be able to climb the hill without pedalling. If the rider pedalled harder than 100w, both bikes would climb faster, but the Ezee would become more efficient and the power difference would increase, so the Bosch would never be able to catch it.

Most of what people are saying about how fast they can climb a 20% hill is just dreaming. To climb at 15 mph requires 1141W (100kg all-up weight). The most the Bosch can provide is about 518w, which would mean that the rider would have to provide 623w. That's what a fit person can do sprinting up stairs. I'm sure there are guys on the forum can do that for a short burst, but not the average forum reader will struggle to maintain 200w for any length of time.

Working back the other way, the Bosch at 18 amps, 36v and an efficiency of 80% (very optimistic), can produce 518W. Add 200w rider input, and let's ignore drive-train losses for now. that gives a net power of 718w, which can propel a 100kg all-up weight up a 20% hill at 7.9 mph.

I hope these facts and figures put some of these myths into perspective.

... I can accept the majority of these figures without question! However the efficiency ones , I have difficulty with. If the hub motors designed speed is 250 rpm, thence it will be rotating at 40% of designed speed and. I would suggest ,that an efficiency of 70% would under those conditions highly optimistic. Whereas the Bosch motor would / should be at optimum rotation speed and therefore higher than the 70% claimed.
If the hub motor was mounted in a small diameter wheel, And was therefore optimised, then it's higher power rating would win out.

 

[Mal69]

... I can accept the majority of these figures without question! However the efficiency ones , I have difficulty with. If the hub motors designed speed is 250 rpm, thence it will be rotating at 40% of designed speed and. I would suggest ,that an efficiency of 70% would under those conditions highly optimistic. Whereas the Bosch motor would / should be at optimum rotation speed and therefore higher than the 70% claimed.
If the hub motor was mounted in a small diameter wheel, And was therefore optimised, then it's higher power rating would win out.

The Oxygen bike I am getting is hub, it quotes efficiency at 85% and I am getting it because my legs are weaker now and I need to get up those hills, I will be disappointed with the bike if I struggle.

 

[anotherkiwi]

Correction 22.58 km/h. No dongle required to beat that time, fairly sure on the right day I could beat that on my Bosch Classic.

http://www.climbing-records.com/2013/07/all-time-top-100-fastest-rides-on.html

Damn forgot to convert the minutes into percentage of hours...

 

[Danidl]

The Oxygen bike I am getting is hub, it quotes efficiency at 85% and I am getting it because my legs are weaker now and I need to get up those hills, I will be disappointed with the bike if I struggle.

... That figure presumably is the peak efficiency, when the motor is running at its designed speed, if the motor were stalled , for instance, it will still be consuming the same (or more ) electrical power but its mechanical power out is zero and all the electrical power appears as heat. If the motor is running at 50% of peak speed, it's efficiency is much less than optimum, .. but after what value depends on the type of technology employed

 

[Woosh]

... I can accept the majority of these figures without question! However the efficiency ones , I have difficulty with. If the hub motors designed speed is 250 rpm, thence it will be rotating at 40% of designed speed and. I would suggest ,that an efficiency of 70% would under those conditions highly optimistic. Whereas the Bosch motor would / should be at optimum rotation speed and therefore higher than the 70% claimed.
If the hub motor was mounted in a small diameter wheel, And was therefore optimised, then it's higher power rating would win out.

in practice, the efficiency of the Ezee or Bafang BPM (which has internal gear reduction ratio of 1:5) is about 61% for the Ezee 250 RPM and 57% at 40% of its maximum efficiency speed (chart from ebikes.ca).
the issue is that torque systems like the Bosch are limited by user input times 3 - how long and how much can you keep up?
The Chinese use rotation sensors, the motors keep delivering as much as you want, whatever your age and condition.

 

[Danidl]

Torque multiplier systems are not suitable for some people. I can't understand why people on this forum keep recommending them to guys that have arthritis, weak legs or are otherwise not able to pedal hard. You'd be better off with something like a Wisper Torque or a Woosh.

This thread started by comparing an Ezee motor at 48v and 18 amps with a Bosch up a 20% hill. Unless the rider is substantially overweight and assuming the standard 250 rpm version, the Ezee will win hands down.

With a total weight of 100kg and about 100w of rider input, the Ezee bike will climb the hill at 9 mph without overheating, running at an efficiency of 70%. The load is about 600w and the motor will take 864w from the battery

The Bosch motors run at a max current of 18 amps at 36v (AFAWCT). At an optimistic efficiency of 70%, the most power the Bosch would produce 454w, so it only has 75% of the Ezee's power at that climbing speed.

The Ezee would still be able to climb the hill without pedalling. If the rider pedalled harder than 100w, both bikes would climb faster, but the Ezee would become more efficient and the power difference would increase, so the Bosch would never be able to catch it.

Most of what people are saying about how fast they can climb a 20% hill is just dreaming. To climb at 15 mph requires 1141W (100kg all-up weight). The most the Bosch can provide is about 518w, which would mean that the rider would have to provide 623w. That's what a fit person can do sprinting up stairs. I'm sure there are guys on the forum can do that for a short burst, but not the average forum reader will struggle to maintain 200w for any length of time.

Working back the other way, the Bosch at 18 amps, 36v and an efficiency of 80% (very optimistic), can produce 518W. Add 200w rider input, and let's ignore drive-train losses for now. that gives a net power of 718w, which can propel a 100kg all-up weight up a 20% hill at 7.9 mph.

I hope these facts and figures put some of these myths into perspective.

It is regrettable. That Bosch and other torque sensing motor vendors don't allow the torque multiplier be altered by the user, they could for instance change the multiplier , adjustment increment up to 99. ,. And still be compliant with the law. .. it would only be a software mod,and would address the types of concern you have expressed

 

[Woosh]

It is regrettable. That Bosch and other torque sensing motor vendors don't allow the torque multiplier be altered by the user, they could for instance change the multiplier , adjustment increment up to 99. ,. And still be compliant with the law. .. it would only be a software mod,and would address the types of concern you have expressed

they may have to deal with other issues - such as abuse of their motors.
If you allow user setting of the multiplier, nothing stops the bike to pull maximum power from standstill or at maximum derestricted speed.