Article The new Performance CX Race, for ebike racing

[Mikerb]

My XC race cadence was usually 85-90 anyway. Not sure why I'd want a motor optimized for 100+

as far as I can see there are very few people who could exceed 80 during the limited motor assisted speed range of a pedelec except in a very low gear on a steep incline.... and then only for a short space of time/distance.
The motors are designed to provide as natural as possible motor assistance up to and including the maximum power output of the motor........within a speed range of 0 to 20kph or slightly more in some regions. How that power is delivered is determined by software algorithms that specify amps delivered against rider torque and cadence ( for each mode). The peak power in turn is controlled by the ( legal) continuous power rating of 250w. Any comparisons with non pedelecs ( ie motor cycles) is not relevant given the criterea to create a legal pedelec.
Bosch are tight lipped a bout what motor changes have been made but do claim a reduction in weight. I suspect the design in unchanged and the weight saving has been achieved by using lighter materials for items like bearings and possibly transfer gears.

 

[MountainBoy]

A bad comparison, but how I can describe it, is that Brose feels more like a diesel engine VW ID4. Bosch like a Tesla.

There. FTFY!

 

[EchoLima21]

This isn't really a very good example.

For starters the OW02, whilst stunning, wasn't lighter or more powerful. It was actually homologated to comply with the German 100hp limit, so it was actually heavily de-tuned with the knowledge that anyone buying it would re-build the motor with higher spec components to get the race performance required (unless you forgot the change the cams, then they failed). Agreed, it was extremely expensive though !

The CX4 Race is pulling the same power, so theoretically no more strain (not knowing the component changes, it might just be a magnesium case like a Brose Mag S with bonded bearings and then lots of failures...) However it ups assistance in Race mode to 400% from 340% so you don't have to pedal as hard for the same assistance (for example, the EP8 is 400%). The other obvious change is the longer over run, which means you can crank it over obstacles easier and learn to use those moments to your performance advantage.

Presumably, the limited run means there is an exception to the pedalec rules as I thought the overrun was limited to less than that.

It's not so much more power as a change in the way the power is delivered.

The German “100bhp limit” never really was (there was an ‘limit’ on kilowatts) and was abandoned long before the R7. You might be confused with TÜV, which are strict laws on what can be changed on road bikes.
The French did have a 100bhp limit (until 2016/17), but the R7 was actually de-powered (the second set of injectors didn’t work without the race loom) rather than limited.
With the race loom fitted it was, as near as damnit, 160bhp.

 

[Onetime]

What's this rattle you rattle about? I don't notice any rattle!

My Bosch doesn’t rattle either. Maybe it’s just the older ones.

 

[Lee Dove]

I was thinking of moving from Shimano to Bosch on my next bike, If I can get one of these along with the new minimal displays then it is a done deal. That Whyte looks good.

 

[emtbeast]

My XC race cadence was usually 85-90 anyway. Not sure why I'd want a motor optimized for 100+

Hey, yes that is your average cadence. That is also my average cadence.

What I am talking about is exactly what you said in your answer.

To elaborate, I live just under a 1200m mountain where the WC DH races are held, the slope range goes all the way from 6% to 15%...so I have a looot of options for serious climbing.

I monitor my cadence very closely and in the really steep parts where u use a low gear higher assistance level the cadence goes beyond 120rpm(can send screenshots if you don't believe me)...so you are out of the ideal power band(high assistance) and out of ideal cadence range(low gear)...and how that feels probably you know...if not then you need to find steeper and longer hills.

One thing to have in mind, all the motors are based on sensors, one of them being the magnet. Some motors when you do a half(technical climbing) pedal stroke(magnet moves past the sensor twice in a very short time)motor registers that as one revolution...and with such pedal strokes the cadence can rise up to 140+(like TQ mentioned they did in their tests).

The problem with any low power systems(in this case 250W limited emtb motors) is that you need to keep it in an ideal power band and so that is managed in one part with internal gearing for ideal pedaling speed(cadence) down/up gearing to match the motor speed, the other part is software/firmware that manages electric current, the voltage drops with discharge so the unless the software is smart enough to compensate with current increase then you can also feel the snall power drop in the lower third of the battery charge.

So for this/my type of riding and racing of course it would definitely be a good decision to optimize a motor for a higher ideal cadence range and some first reports do also say that it supports with the same level in higher cadence ranges.

I have only ridden the CX Performance once and ride along a friend usually so know how it sounds. Well I heard the new CX Race variant in a German yt channel in a comparison, and to me it sounded quite differently(with a high pitched sound), even the revier mentioned that the best way to describe the sound is that of high powered electric RC cars.

The other thing is that Bosch didn't want to share exactly what the internal changes are even after several attempts by another German yt channel.

Well time will tell what's inside of the new motor. I know I will be riding my beast for another season and let the new stuff be beta tested by someone else, as there has been a lot of this in different tech departments...don't feel good being a test dummy for software updates etc...for this kind of money we give for ebikes...at the end they are still just a bycicle with some extra...

 

[RickBullotta]

Hey, yes that is your average cadence. That is also my average cadence.

What I am talking about is exactly what you said in your answer.

To elaborate, I live just under a 1200m mountain where the WC DH races are held, the slope range goes all the way from 6% to 15%...so I have a looot of options for serious climbing.

I monitor my cadence very closely and in the really steep parts where u use a low gear higher assistance level the cadence goes beyond 120rpm(can send screenshots if you don't believe me)...so you are out of the ideal power band(high assistance) and out of ideal cadence range(low gear)...and how that feels probably you know...if not then you need to find steeper and longer hills.

One thing to have in mind, all the motors are based on sensors, one of them being the magnet. Some motors when you do a half(technical climbing) pedal stroke(magnet moves past the sensor twice in a very short time) register that as one revolution...and with such pedal strokes the cadence can rise up to 140+(like TQ mentioned they did in their tests).

The problem with any low power systems(in this case 250W limited emtb motors) is that you need to keep it in an ideal power band and so that is managed in one part with internal gearing for ideal pedaling speed(cadence) down/up gearing to match the motor speed, the other part is software/firmware that manages electric current, the voltage drops with discharge so the unless the software is smart enough to compensate with current increase then you can also feel the snall power drop in the lower third of the battery charge.

So for this/my type of riding and racing of course it would definitely be a good decision to optimize a motor for a higher ideal cadence range and some first reports do also say that it supports with the same level in higher cadence ranges.

I have only ridden the CX Performance once and ride along a friend usually so know how it sounds. Well I heard the new CX Race variant in a German yt channel in a comparison, and to it sounded quite differently(with a high pitched sound), even the revier mentioned that the best way to describe the sound is that of high powered electric RC cars.

The other thing is that Bosch didn't want to share exactly what the internal changes are even after several attempts by another German yt channel.

Well time will tell what's inside of the new motor. I know I will be riding my beast for another season and let the new stuff be beta tested by someone else, as there has been a lot of this in different tech departments...don't feel good being a test dummy for software updates etc...for this kind of money we give for ebikes...at the end they are still just a bycicle with some extra...

A counterargument would suggest that you're geared incorrectly if you're spinning 120 on an eMTB though...

 

[emtbeast]

A counterargument would suggest that you're geared incorrectly if you're spinning 120 on an eMTB though...

If you ever come to Maribor I can take you along my usual 1Km d+ 10% average incline monster climb and then you can tell me if I am geared right pushing 120+rpm

 

[RickBullotta]

If you ever come to Maribor I can take you along my usual 1Km d+ 10% average incline monster climb and then you can tell me if I am geared right pushing 120+rpm

That would be awesome! I was in Slovenia earlier this summer and should have done some riding.

 

[emtbeast]

That would be awesome! I was in Slovenia earlier this summer and should have done some riding.

You are more than welcome ✌ just give me a poke and we can work something out