New Bosch Coming!

[tillson]

Again. Should t we be more interested in an honest torque figure?

Torque alone is meaningless. With the correct gearing, I could make the motor which drives the second hand on my wrist watch produce more torque than a Bosch motor, or any Ebike motor for that matter. It would be more meaningful if the manufacturers quoted T Nm at W rpm for example. Then you would get an idea of how the motor will perform on the bike.

 

[Martin@e-bikeshop]

Both at approx 80 rpm:
Bosch Performance = 60Nm
Yamaha X94 = 70Nm / 60Nm continuous
Both will assist up to 100 rpm.

Bosch performance CX = 75Nm up to 120rpm

 

[tillson]

Both at approx 80 rpm:
Bosch Performance = 60Nm
Yamaha X94 = 70Nm / 60Nm continuous
Both will assist up to 100 rpm.

Bosch performance CX = 75Nm up to 120rpm

Bosch 500 Watts

Yamaha 580 Watts

Bosch performance 940 Watts

 

[JohnCade]

Bosch 500 Watts

Yamaha 580 Watts

Bosch performance 940 Watts

The maximum wattage is more relevant than a torque figure IMO, and I wanted to know what it was for different motors. What is it for the Impulse 11 I wonder. On those figures the Bosch performance is a lot more powerful than I thought it was.

 

[Deleted member 4366]

Hold on. You didn't read what I wrote. Also, I guarantee that the Bosch doesn't make 75NM at 120 rpm. It might make 75NM and it might spin to 120 RPM, but not both at the same time.

According to Martin's website, the Bosch sprocket rotates 2.5 times the speed of the Yamaha for the same bike speed. If the Yamaha makes the same torque as the Bosch, it would produce 2.5 times the power, which clearly it doesn't. The above claims of torque are absolutely meaningless.

 

[farmer]

Forget about torque, power is the issue and power=force x speed.

 

[tillson]

Forget about torque, power is the issue and power=force x speed.

which equals torque x motor shaft speed, so to torque is very relevant.

I'm just taking Martin's torque and motor speed figures at face value. I don't know whether they are correct.

 

[Deleted member 4366]

They can't be correct because they have completely different sized motor sprockets.

To be meaningful, the torque would have to be quoted as something like 60NM back wheel torque in bottom gear with a 34T bottom gear sprocket. If there's options for the motor sprocket, that would have to be declared too.

 

[JohnCade]

So since as I always suspected these torque figures are essentially marketing terms and so meaningless. What is the relative power or wattage of the main CD motors? I assume wattage would be the best way to measure power output at these sorts of levels.

 

[Deleted member 4366]

They won't want to say because of political implications. That's why they use torque.

 

[ray74]

So is the new Bosch cx motor more powerful than the Yamaha do you think? Just wondered as I'm not sure which one to go for. I have a haibike with the yamy motor at the moment but just wondered if I would notice any difference in the new Bosch?

 

[soundwave]

http://www.e-mountainbike.com/news/specialized-turbo-levo-fsr-e-fully-mit-integriertem-akku.1386346.1347412.htm

90nm 460 or 504 watt-hours

 

[Deleted member 4366]

So is the new Bosch cx motor more powerful than the Yamaha do you think? Just wondered as I'm not sure which one to go for. I have a haibike with the yamy motor at the moment but just wondered if I would notice any difference in the new Bosch?

Are you sure you're not getting carried away with hype? Does your Yamaha not provide enough torque? Don't forget that any extra power will have to come from the battery.

 

[ray74]

Yeah you're right. Thinking about it after I wrote that I thought there's no point changing to a Bosch if I'm so happy with the Yamaha. I am changing to a full sus but going to stick with the motor I know.

 

[RobF]

Yeah you're right. Thinking about it after I wrote that I thought there's no point changing to a Bosch if I'm so happy with the Yamaha. I am changing to a full sus but going to stick with the motor I know.

If you are changing to full sus anyway, it would be worth trying a Bosch.

They do ride slightly differently, the Bosch being a bit smoother and more refined.

The Yamaha motor is probably on a par with a Bosch, possibly the Performance version.

I've not tried a CX, but the Performance has noticeably more poke than the standard, so I expect the CX will be pokier again.

In other words, you can believe Bosch when they say the CX has more torque, even if the quoted figures are meaningless in use.

Another plus for a new Bosch is the option of a bigger 500wh battery.

On t'other hand, Yamaha bikes have a standard size front ring and can run two rings at the front.

Superior, in my view, to the tiny front ring on the Bosch bikes which I see as giving no advantage.

 

[soundwave]

you can put 2 on the bosch 14t +16t ect tho will have to manually change them.

 

[ray74]

Yeah I tried both Bosch performance and Yamaha at sherwood pines late last year at a haibike test day. I preferred the Yamaha more that time because it felt more instant and pokier. One of the main reasons for looking at the 2016 Bosch was the 500Wh battery and the little extra torque but the xduro allmtn Rc costs £3800 and the Sduro Rx costs £3700 but gains better brakes, dropper seat post and the E.I suspension. ( bit of a no brainer really ).
The new Bosch would have to be much better for me to consider it, I am off to the 2015 cycle show at the nec in September and Raleigh came back to me saying that they will have the new 2016 haibikes there but no response on if they will be there to ride as of yet.

 

[soundwave]

they got problems tho with that ei sus

http://www.pedelecforum.de/forum/index.php?threads/sduro-allmtn-rx-e-i-shock-defekt.33596/

 

[Deleted member 4366]

We should be seeing the Bafang Maxdrives in the shops soon. They should be pretty good.

 

[soundwave]

there any prices for those ?