Centrelock to 6 bolt conundrum

[Bobba Fett22]

Hi everyone,

I've got an M20 rise ebike and a bontrager rear carbon wheel. It's a 6 bolt I'm wondering if there a way (adapter) to use shimanos centrelock discs or is there any 6 bolt compatible ebike rotors out there ?

 

[mark.ai]

The Rises which have 6 bolt rotors by default come with Galfer rotors: Products – Galfer Bike

But any make should work, e.g. I’ve switched to Hayes ones.

So if you have one on your Bontrager wheel already, then it should be fine. (So long as the radius and thickness match.)

 

[Bobba Fett22]

I see, it's the rear ones I need do they have the speed sensor magnet?

 

[mark.ai]

Ahhh yes you would also need the magnet attachment This is the part: MAGNET DISC 6 BOLT ORBEA — Orbea
It connects to 2 of the 6 bolts.

Do the centrelock rotors come with the magnet already attached somehow?

 

[Bobba Fett22]

Brilliant many thanks. They come with Shimano rotors which already have built in magnet. Shame they only make it in centrelock

 

[Murphius]

I just used JB Weld to adhere a small neodymium magnet to my Magura rotor. Super easy/cheap/quick alternative.

 

[Interpaul]

@Murphius My Rise has centre locks - I want to try a 27.5 wheel that has a 6 bolt rotor on the rear that I have spare, don't want to buy any new discs as I have a 6 bolt one lying around so sticking a magnet to it sounds like a good plan.

What dimension was the magnet that you used, and where about on the disc did you attach it - If I were to stick a magnet on I am concerned it may foul the sensor or brake calliper?

 

[Murphius]

@Murphius My Rise has centre locks - I want to try a 27.5 wheel that has a 6 bolt rotor on the rear that I have spare, don't want to buy any new discs as I have a 6 bolt one lying around so sticking a magnet to it sounds like a good plan.

What dimension was the magnet that you used, and where about on the disc did you attach it - If I were to stick a magnet on I am concerned it may foul the sensor or brake calliper?

I used an 8mm diameter x 3mm thick magnet. The radius of the centerline for the magnet is about 7 mm greater than the radius of the centerline for the 6 bolt pattern. You can just eyeball it and make sure you locate the magnet in line with the sensor on the chainstay. With my Magura rotor, the magnet would hold itself (at low speeds on a stand) so I was able to verify it worked prior to using JB Weld.

 

[Bigtuna00]

You don't even need to JB weld it TBH. I ran a rotor with the magnet stuck on the rotor for weeks without issue. You can even carry a spare magnet in case it falls off. I used 10x8mm magnets (Lot of 10 Brand New Neodymium Magnets N52 Grade 10mm x 3mm Round Discs (.39") 723260764108 | eBay).

 

[Murphius]

You don't even need to JB weld it TBH. I ran a rotor with the magnet stuck on the rotor for weeks without issue. You can even care a spare magnet in case it falls off. I use 10x8mm magnets (Lot of 10 Brand New Neodymium Magnets N52 Grade 10mm x 3mm Round Discs (.39") 723260764108 | eBay).

Mine would slide around without adhesive, I wouldn’t risk it. No magnet = no motor. Could happen at a very inopportune time.

 

[irie]

You don't even need to JB weld it TBH. I ran a rotor with the magnet stuck on the rotor for weeks without issue. You can even care a spare magnet in case it falls off. I use 10x8mm magnets (Lot of 10 Brand New Neodymium Magnets N52 Grade 10mm x 3mm Round Discs (.39") 723260764108 | eBay).

 

[ebsocalmtb]

I jb welded the rare earth magnets to my 6 bolt rotors. 2,500 miles on my rise with 2 different wheelsets setup this way and I have zero issues.

 

[Hardtail]

Maybe this is useful? Shimano Ep8 ebike users with 6 bolt rotors

I used an adapter to go from centrelock hub to 6-bolt discs but it wasn't ideal and always had a bit of play, I ended up buying centrelock discs... I guess there must be an adapter that goes the other way.

 

[Interpaul]

Maybe this is useful? Shimano Ep8 ebike users with 6 bolt rotors

I used an adapter to go from centrelock hub to 6-bolt discs but it wasn't ideal and always had a bit of play, I ended up buying centrelock discs... I guess there must be an adapter that goes the other way.

Thanks, I am actually doing it the opposite way. The 27.5 wheel I have is 6 a bolt hub and I have a 6 bolt rotor without magnet - so gonna stick a magnet to it to see if I like the mullet