Do most speed sensor systems use a magnet that's mounted to a wheel spoke

[TedCot]

Hello,

I'm a newbie who's shopping for his first ebike.
After doing some research, I've sort of narrowed my choices between Specialized and Giant.
Specialized seems to provide a very well thought-out package but problems with their motors sort of deter me.
Giant also seems to offer a good package but definitely not as complete as Specialized.
What turns me off, in particular, is their use of a magnet being mounted on a wheel spoke to measure speed.
Is this common practice for ebike manufacturers?
Magnets mounted this way can get knocked out of place or off the wheel altogether, which can be particularly problematic for ebikes.
Do other brands other than Specialized mount their magnets elsewhere on the wheel.
Thanks.

 

[fooferdoggie]

its not really a issue two of my bosch bikes have them get the positioned right and tight they are petty reliable. having it on the hub is nice but it limits to you to the rotor type the biek came with. like my trek has a sensor on the disc on a 6 hole bolt mount. so whe nI got new wheels I was stuck with that over a qucik lock disc. Plus I bumped the sensor getting the wheel on and cracked the mounting hole.

 

[AHicks]

No interest in a throttle?

To answer your question about magnet location, yes, mounting a magnet to a spoke is pretty commonly done on a lot of bikes.

 

[Stefan Mikes]

What turns me off, in particular, is their use of a magnet being mounted on a wheel spoke to measure speed.

Specialized and Giant e-bikes have the magnet mounted on the hydraulic brake rotor. What e-bike model are you talking about?!

The speed magnet in a Specialized Vado e-bike. There is a bracket with the magnet screwed to the rear brake rotor. The speed sensor is tucked into the e-bike chainstay. (The 6-bolt type bracket/rotor).

The speed magnet bracket in a Giant Trance E+ e-bike. There, the mount type of the bracket/rotor is Centerlock.

A speed magnet bracket for Centerlock disk brakes (Giant Trance E+, Specialized Vado SL).

 

[PedalUma]

Art's bike is shipping today. It is very well packed. But in order to properly protect the drive side chain stay I needed to rotate the speed sensor pickup 90 degrees down. To function, the pickup and wheel magnet need to be perfectly aligned. There is a microscopic black arrow on the black surface of the pickup for alignment with the spoke magnet. Normally I remove speed sensors on my own bikes to improve performance and reduce wires.

 

[Stefan Mikes]

Normally I remove speed sensors on my own bikes to improve performance and reduce wires.

That's why you are not employed by either Specialized or Giant!

 

[Bicyclista]

Giant also seems to offer a good package but definitely not as complete as Specialized.
What turns me off, in particular, is their use of a magnet being mounted on a wheel spoke to measure speed.
Is this common practice for ebike manufacturers?
Magnets mounted this way can get knocked out of place or off the wheel altogether, which can be particularly problematic for ebikes.

Both my Haibike and my Yuba ebikes use a magnet mounted on a wheel spoke. I've owned the Haibike since 2016 and and have over 15,000 miles, on and off road. I've had the Yuba for 18 months, on and off road, riding it four times a week. No problems with the magnet on either bike whatsoever. Neither potholes nor rough terrain have knocked the magnet off nor displaced it.

Giant uses Yamaha motors which are excellent. In my experience, Yamaha motors are more powerful than Bosch motors, even in those instances where the Yamaha is rated as having a lesser maximum torque than the Bosch. I don't have any experience with Specialized ebikes.

 

[Stefan Mikes]

Giant uses Yamaha motors which are excellent. In my experience, Yamaha motors are more powerful than Bosch motors, even in those instances where the Yamaha is rated as having a lesser maximum torque than the Bosch. I don't have any experience with Specialized ebikes.

I was very fond of the Yamaha motor in my Giant e-MTB (Giant SyncDrive Pro is the brand name of the motor), only it was too loud for my liking. The motor power was enhanced by the mountain grade gearing of that e-bike. The most expensive of Specialized (Brose) motors, the 2.2 (found for example in Vado 5.0) is even stronger in torque and peak Watts (Yamaha 520 W, Specialized 565 W mechanical).

 

[PedalUma]

In 45 min. we pick up the Marin Stinson for me to convert. She was sold a top name bike for $3K plus a $600 maintenance plan that does not cover electrical. But the thing could not climb. She was told & sold that it could. So, I walked her through how to get a full refund. She knows that my bikes climb and are low maintenance. It is getting an 11-50 cassette.

Stinson ST 2

2023 Marin Bikes Stinson ST 2, Aluminum 27.5’’ wheel comfort bike. Designed for casual and comfortable path riding.

www.marinbikes.com

 

[TedCot]

its not really a issue two of my bosch bikes have them get the positioned right and tight they are petty reliable. having it on the hub is nice but it limits to you to the rotor type the biek came with. like my trek has a sensor on the disc on a 6 hole bolt mount. so whe nI got new wheels I was stuck with that over a qucik lock disc. Plus I bumped the sensor getting the wheel on and cracked the mounting hole.

That's a good point.

 

[Stefan Mikes]

That's a good point.

That's not a good point. The brake rotors only come in two flavours: 6-bolt or Centerlock mount. Magnet brackets are available for these two types. Moving a magnet bracket from one brake rotor to another is one of the easiest things you can do about an e-bike. I had the new rear wheel of my big Specialized Vado custom built and it was no issue to remove and reinstall the magnet bracket. Later, I replaced the brake rotors with new ones (and better). Again, no issue to remove and reinstall the magnet bracket, and I am not mechanically inclined at all!

Specialized or Giant e-bikes have their speed sensors well hidden inside the chainstay, and there are no issues with them. I am not familiar with Bosch E-Bikes but the fact foofer did it wrong does not change the general rule: the brake rotor magnets and matching sensors are reliable and easy to work with.

The pictures I showed before come from the e-bikes in my family:

• Specialized Turbo Vado 6.0
• Giant Trance E+ 2 Pro.

The third e-bike (Specialized Turbo Vado SL) has the magnet bracket installed as a Centerlock mount.

 

[TedCot]

Specialized and Giant e-bikes have the magnet mounted on the hydraulic brake rotor. What e-bike model are you talking about?!

View attachment 159899
The speed magnet in a Specialized Vado e-bike. There is a bracket with the magnet screwed to the rear brake rotor. The speed sensor is tucked into the e-bike chainstay. (The 6-bolt type bracket/rotor).

View attachment 159900
The speed magnet bracket in a Giant Trance E+ e-bike. There, the mount type of the bracket/rotor is Centerlock.

View attachment 159901
A speed magnet bracket for Centerlock disk brakes (Giant Trance E+, Specialized Vado SL).

I test rode a Giant Talon E and it had a spoke-mounted magnet. Didn't like the sizing anyway.
Now I wanted to check out the Stance but haven't seen one in person yet. It'd be great if the speed magnet is mounted on the disk same as the Trance.
As for Specialized, I was seriously looking at Vado 3.0 but I'd prefer an eMTB. The Tero 3.0 is nice but the premium (about $1300 CAD) is too much over the Vado for a very similar bike.
Not that I'd be doing technical trails but, as a road cyclist, I want a bike that would take me to places that my road bikes won't.
The Vado may be too city/hybrid for my liking but I'm very impressed with it as a complete package.
It's got the rack, fenders and lights already; and I particularly like the display unit and the connectivity it offers.
My excuse for getting an ebike is to avoid having to take a shower when I commute to work by bike - lots of rolling hills during that 20km commute.
So, it won't be my main bike and the bikes I'm looking at are already over my original budget.
But if I'm already spending thousands of dollars on one I may as well bite the bullet and get something that I'd enjoy and keep.
BTW, a Rocket Mountain Fusion may be another candidate.

 

[fooferdoggie]

That's not a good point. The brake rotors only come in two flavours: 6-bolt or Centerlock mount. Magnet brackets are available for these two types. Moving a magnet bracket from one brake rotor to another is one of the easiest things you can do about an e-bike. I had the new rear wheel of my big Specialized Vado custom built and it was no issue to remove and reinstall the magnet bracket. Later, I replaced the brake rotors with new ones (and better). Again, no issue to remove and reinstall the magnet bracket, and I am not technically inclined at all!

I did what wrong? no one knew I the spacing was the same with the center lock magnet and a regular six bolt magnet. I think the center lock is after away from the center of the brake rotor. so I had the back wheel made with the 6 both just to make sure. it was far harder to find that hub that way now. then I bought another magnet so I could swap wheels without changing the magnet.

 

[Stefan Mikes]

I did what wrong? no one knew I the spacing was the same with the center lock magnet and a regular six bolt magnet. I think the center lock is after away from the center of the brake rotor. so I had the back wheel made with the 6 both just to make sure. it was far harder to find that hub that way now. then I bought another magnet so I could swap wheels without changing the magnet.

6-bolt and Centerlock are two different and incompatible mounts.

6-bolt rotor magnet bracket

Centerlock rotor magnet bracket

You cannot pick any of them and try to replace another as you please and then say it was an issue.

 

[Stefan Mikes]

I test rode a Giant Talon E and it had a spoke-mounted magnet. Didn't like the sizing anyway.

I agree some less expensive Giant e-bikes might come with the spoke magnets. That's why you are getting a reliable modern solution with more expensive e-bikes.

A Stance E+ could be very good for you! Giant can make nice and decently priced e-MTBs, and the Stance is a full-suspension one. Yes, the Stance has the magnet installed on the brake rotor.

There is only one thing I would like to make you aware of: The Stance is a purely off-road e-bike. It is not an all-rounder e-bike. I made a mistake three years ago buying a Trance E+ to realize I had to transport it to the trails with my car, as it was a pain to ride an off-road e-bike on the pavement... Loud, slow, tiresome, and with a disappointingly low battery range.

The Tero is more an all-rounder.

 

[PedalUma]

What about using spinners on the wheel magnets?

 

[Stefan Mikes]

Why do you always write off-topic Uma?
Hint: Don't smoke and write.

 

[fooferdoggie]

6-bolt and Centerlock are two different and incompatible mounts.


6-bolt rotor magnet bracket


Centerlock rotor magnet bracket

You cannot pick any of them and try to replace another as you please and then say it was an issue.

I never said I did that I said I had to pick a 6 bolt hub over a center lock hub because of the magnet since the bike had a 6 bolt disc already.

 

[Stefan Mikes]

I never said I did that I said I had to pick a 6 bolt hub over a center lock hub because of the magnet since the bike had a 6 bolt disc already.

You could select a matching hub and rotor including a proper magnet bracket? Or, I really cannot understand.

 

[fooferdoggie]

You could select a matching hub and rotor including a proper magnet bracket? Or, I really cannot understand.

me thinks your not getting the English thats what I said I did.