Go Faster Dongles! Here's another to consider

[WorldClassAccident]

The Bosch software update fixed this

http://ebikeee.com/2012/01/03/bosch-engine-tuning-at-home/

It did not fix my solution. My solution uses the standard hardware in the standard manner so the software isn't aware of it.

The computer is being told that you are riding at 6mph so is happy producing assist. There is not electronic trickery, just a change of how often the magnet passes the sensor.

 

[soundwave]

so what is the cut off speed now? as this mod has been out for years so im unsure why it works with the bike you have.

also what is the wheel size set to?

 

[WorldClassAccident]

It is quite simple.

The computer counts how long between the times the magnet passes the sensor. It is programmed to calculate the speed based on the wheel size.

Bigger or slower wheels will affect the accuracy of this calculation exactly as they do on your car.

The other option is to reduce how often the magnet passes the sensor. This is what my approach does as your pedals rotate more slowly than your wheels.

7.6mph on the display = 28mph on a gps system when in top gear

The Bosch software 'fix' doesn't apply as it still sees the magnet passing the sensor so assumes everything is normal.

 

[soundwave]

put the sensor back and change that also 7.6 mph =28mph is more than x3 times that on the display as it would be under 24mph not 28?

my cut off speed is 34.5 mph and shows half that on the display.

 

[WorldClassAccident]

Hi, not sure what you are saying in your last post.

Because the computer uses my pedalling cadence to calculate speed if I slow the pedalling down the speed display will drop quicker than the real speed. I can roll down a hill at a fair pace with the speedo reading zero. The 7.6=28 was approximate as I had been pedalling like a loon to see how fast I could go. I probably slowed my pedalling to glance at the speedo.

The maximum speed to which the motor would assist is when my pedalling cadence it the same as the number of times a wheel rotates at 15mph. I am not going to try and do the maths properly but approximately.

7.5mph displayed = 28mph reality
Therefore
15mph displayed = 56mph reality
That means the assist will stop helping you at approximately 60mph!

However, you would have to be pedalling at something stupid like 250rpm and providing enough power to keep the bike accelerating which is highly unlikely. This fix doesn't increase the power of the assist, just stops it cutting out.

In reality it just allows you to keep up with your mates on private roads where their speed might drift up to 18-20mph which is relatively easy on tarnac

 

[Gubbins]

put the sensor back and change that also 7.6 mph =28mph is more than x3 times that on the display as it would be under 24mph not 28?

my cut off speed is 34.5 mph and shows half that on the display.

My display doesn't give a wheel circumference adjustment. I am guessing that appears after a firmware update.

 

[WorldClassAccident]

No need to change anything about wheel size for my modification, simply move the sensor and magnet

 

[Artstu]

The Bosch software update fixed this

http://ebikeee.com/2012/01/03/bosch-engine-tuning-at-home/

It did not fix my solution. My solution uses the standard hardware in the standard manner so the software isn't aware of it.

The computer is being told that you are riding at 6mph so is happy producing assist. There is not electronic trickery, just a change of how often the magnet passes the sensor.

I'm amazed that this works for you. Bosch in their quest to prevent people doing this set it up so an error code came up when crank speed matched what should have been wheel speed, so the system then knows what you've done because the crank speed is exactly matching the wheel sensor speed (on the Classic motor at least)

 

[flecc]

I'm amazed that this works for you. Bosch in their quest to prevent people doing this set it up so an error code came up when crank speed matched what should have been wheel speed, so the system then knows what you've done because the crank speed is exactly matching the wheel sensor speed (on the Classic motor at least)

But if the wheel sensor is moved to the crank area, hasn't the Bosch then just got only the one feedback from the crank and no way to sense wheel speed?
.

 

[Gubbins]

But if the wheel sensor is moved to the crank area, hasn't the Bosch then just got only the one feedback from the crank and no way to sense wheel speed?
.

Does it have an internal cadence sensor?

 

[WorldClassAccident]

I am not aware of any crank speed sensor and from the results I get (on private land) I suspect not.

Latest bike, motor, computer and everything.

Not sure how that would work anyway as Bosch don't control the gears you run so a 1:1 ratio would be possible anyway

 

[Artstu]

But if the wheel sensor is moved to the crank area, hasn't the Bosch then just got only the one feedback from the crank and no way to sense wheel speed?
.

That's why I said "what should have been wheel speed"
The new Bosch motor does complicate matters slightly, but I'm still surprised Bosch haven't done something to prevent what was an early cheat on the system.

 

[Artstu]

I am not aware of any crank speed sensor and from the results I get (on private land) I suspect not.

Latest bike, motor, computer and everything.

Not sure how that would work anyway as Bosch don't control the gears you run so a 1:1 ratio would be possible anyway

There is a crank speed sensor. I do occasionally match that 1 :1 and get a brief error, the system allows it to happen briefly, but yours will be matching it perfectly.

 

[nemesis]

i tried the crank trick on mine and it worked for about 10 secs and then the motor cut out with a 503 error code on the console,2015 bosch performance line,i had a magnet the right size and the speedo pickup was positioned and aligned.

 

[flecc]

i tried the crank trick on mine and it worked for about 10 secs and then the motor cut out with a 503 error code on the console,2015 bosch performance line,i had a magnet the right size and the speedo pickup was positioned and aligned.

It must have an internal crank sensor then, the software not allowing the wheel and crank sensors to be identical, throwing up an error.

Worldclassaccident's unit must either be without the internal sensor or it's (fortunately) faulty.

P.S. Does it have a separate speedo sensor on the wheel?
.

 

[Artstu]

It must have an internal crank sensor then, the software not allowing the wheel and crank sensors to be identical, throwing up an error.

Worldclassaccident's unit must either be without the internal sensor or it's (fortunately) faulty.

P.S. Does it have a separate speedo sensor on the wheel?
.

That's what I said. and the speedo sensor is the one that gets turned to the pedal crank in this mod.

 

[flecc]

That's what I said. and the speedo sensor is the one that gets turned to the pedal crank in this mod.

Thanks Artstu, I'm not familiar with these units, being used to the more simple single wheel speed sensor of Panasonic and Impulse units. In those it's the wheel rotation sensor that's changed to the crank, hence my query about the Bosch methods.
.

 

[WorldClassAccident]

Give me a minutes and I will post some clearer pictures. I don't mind if it is possible or not, as long as it continues to work for me

 

[Gubbins]

Being a numpty.... so probably talking a load of B*****cks.
If a 29er was reset for a 26 inch wheel wouldnt that give a bit of a boost?

 

[Artstu]

In those it's the wheel rotation sensor that's changed to the crank,

That's the exact mod being used here in this thread.