Anyone blowing through speed sensors?

Plummet

Flash Git
Mar 16, 2023
1,152
1,634
New Zealand
I've got the mini rotor magnet speed sensor. The first one lasted 6 months and just stopped working.

Now 3 weeks later ive blown through a second one......

Hmmm. It's going start getting expensive if thus keeps on happening.
 

Zimmerframe

MUPPET
Subscriber
Jun 12, 2019
14,028
20,815
Brittany, France
Yup, same problem.

When I ride too fast I burn them out. There's too much harmonic wave destruction as the magnet passes the hall sensor when you're consistently over 80kph+ . It's like being hit with an electronic sledgehammer.

You can either strip the sensor and remove 90% of the coils.

Move the sensor to the outside of the swing arm, or possibly under the saddle depending on your speed.

Or, I found it easier to swap to a pin head magnet.
 

Onetime

Active member
Aug 10, 2022
468
480
Cali
Yup, same problem.

When I ride too fast I burn them out. There's too much harmonic wave destruction as the magnet passes the hall sensor when you're consistently over 80kph+ . It's like being hit with an electronic sledgehammer.

You can either strip the sensor and remove 90% of the coils.

Move the sensor to the outside of the swing arm, or possibly under the saddle depending on your speed.

Or, I found it easier to swap to a pin head magnet.
Do you have a pic of the magnet your using?
 

Plummet

Flash Git
Mar 16, 2023
1,152
1,634
New Zealand
No issues here on Bosch Smart system. I don't even know where the sensor is on my Rail but I presume the rotor :ROFLMAO:
I'm thinking that it might be the pole routing of the sensor. It was floating close to he rotor, could easily be caught by a stick and or vibrate onto the rotor.

I've gone sneaky with this routing
20240216_071701.jpg
 

cozzy

E*POWAH Elite
Subscriber
Aug 11, 2019
934
1,044
Hampshire UK
I'm thinking that it might be the pole routing of the sensor. It was floating close to he rotor, could easily be caught by a stick and or vibrate onto the rotor.

I've gone sneaky with this routing View attachment 134575
That sensor looks much bigger than I expected compared to seeing a picture of one.
I'll be buying one soon if my voima ever gets delivered.
 

cozzy

E*POWAH Elite
Subscriber
Aug 11, 2019
934
1,044
Hampshire UK
Why did you swap away from the rim magnet sensor? 1300 miles and no issues on my Voima with it.
I can tell you why I will be doing it. Going mullet so the sensor will be further away, plus for possible future speed modifications.
 

cappuccino34

Active member
Nov 24, 2020
530
329
Helmshore
The mount that Mondraker use is much nicer than the crappy Bosch 'P-clip' style.
I'm wondering if it's rattling around and causing the failures.
Also, are your wheel bearings good and it's not the disc magnet hitting the sensor?
 

Plummet

Flash Git
Mar 16, 2023
1,152
1,634
New Zealand
The mount that Mondraker use is much nicer than the crappy Bosch 'P-clip' style.
I'm wondering if it's rattling around and causing the failures.
Also, are your wheel bearings good and it's not the disc magnet hitting the sensor?
Bearings are good. But it's damn close. The one sided pole clamp is pretty average so likely it might be hitting. I'll do some closer inspection
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,565
5,055
Weymouth
What is the white stuff on the sensor??
The "P" clip that holds the sensor has a groove in its centre, into which the shoulder midway along the sensor fits, such that the sensor cannot move. This means the sensor can only be properly located into the "P" clip by opening the clip, installing the sensor and ensuring the groove and shoulder line up. If that has not been done the sensor will move and if it moves more that a bout 5mm it will cease to work.
 

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