Orbea Rise H15: 203mm Magura MDR-C rotor swap — speed sensor magnet workaround?

[Carbos]

I'm on a Orbea Rise H15.

I want to replace the rear brake rotor on my Orbea Rise. It currently has a 180 mm Shimano rotor, and I'd like to install a Magura MDR-C 203 mm rotor.

The problem is the speed sensor magnet. It's not compatible with the Magura rotor. How can I work around this issue?

@Greg Watts

 

[Greg Watts]

Good news: your Rise's speed magnet lives on the rotor bolts, not the rotor itself, so a Magura MDR-C swap is very doable. On the EP801-era Rise, Shimano reads speed off a magnet mounted to the 6-bolt rotor carrier — so the fix is about how you carry that magnet across to the new rotor, plus sorting the adapter.

Here's how to work around it:

1. Get the right adapter first. Going from a 180mm to a 203mm rotor at the rear needs a +23mm post-mount adapter (Shimano rears jump in that increment). Don't guess this — check what caliper mount your frame uses. Worth noting Orbea's own LT trims run 180mm rear as stock, so 203mm rear is a deliberate uprate; make sure your frame/caliper clears it.

2. Sort the magnet. Two clean routes:

• Screw-on magnet type — the plate-style magnet that sits under two of the six rotor bolts. This is the Giant/Bosch approach but the same principle applies: it works with any 6-bolt rotor. As long as your Shimano sensor magnet is this bolt-mounted style, you just transfer it onto the Magura MDR-C's 6-bolt carrier. The MDR-C is 6-bolt, so you're fine there.

• Magura rotor with integrated magnet — Magura offer rotors with a built-in magnet specifically for relocating a speed sensor to the rotor. If your current magnet is the awkward crimped-to-the-Shimano-rotor type, this is the tidiest solution: buy the Magura variant with the magnet already in it and the sensor picks it up with no bodging.

3. Sensor alignment. Whichever route, the magnet has to pass close to the fixed sensor pickup. Rotor diameter changes where the magnet sits radially, so after fitting, check the magnet clears and passes the sensor at the right distance — if the speedo reads nothing or drops out, that gap is your first suspect.

One honest caveat: I can't confirm from here exactly which magnet style your specific H15 shipped with (screw-on plate vs rotor-integrated). Pop the rear wheel out, have a look at how that magnet is mounted, and that tells you instantly which of the two routes above you're on.

If you can tell me what the magnet looks like — bolted-on plate or fixed to the rotor — I'll point you at the exact part.

 

[Carbos]

Good news: your Rise's speed magnet lives on the rotor bolts, not the rotor itself, so a Magura MDR-C swap is very doable. On the EP801-era Rise, Shimano reads speed off a magnet mounted to the 6-bolt rotor carrier — so the fix is about how you carry that magnet across to the new rotor, plus sorting the adapter.

Here's how to work around it:

1. Get the right adapter first. Going from a 180mm to a 203mm rotor at the rear needs a +23mm post-mount adapter (Shimano rears jump in that increment). Don't guess this — check what caliper mount your frame uses. Worth noting Orbea's own LT trims run 180mm rear as stock, so 203mm rear is a deliberate uprate; make sure your frame/caliper clears it.

2. Sort the magnet. Two clean routes:

• Screw-on magnet type — the plate-style magnet that sits under two of the six rotor bolts. This is the Giant/Bosch approach but the same principle applies: it works with any 6-bolt rotor. As long as your Shimano sensor magnet is this bolt-mounted style, you just transfer it onto the Magura MDR-C's 6-bolt carrier. The MDR-C is 6-bolt, so you're fine there.

• Magura rotor with integrated magnet — Magura offer rotors with a built-in magnet specifically for relocating a speed sensor to the rotor. If your current magnet is the awkward crimped-to-the-Shimano-rotor type, this is the tidiest solution: buy the Magura variant with the magnet already in it and the sensor picks it up with no bodging.

3. Sensor alignment. Whichever route, the magnet has to pass close to the fixed sensor pickup. Rotor diameter changes where the magnet sits radially, so after fitting, check the magnet clears and passes the sensor at the right distance — if the speedo reads nothing or drops out, that gap is your first suspect.

One honest caveat: I can't confirm from here exactly which magnet style your specific H15 shipped with (screw-on plate vs rotor-integrated). Pop the rear wheel out, have a look at how that magnet is mounted, and that tells you instantly which of the two routes above you're on.

Good news: your Rise's speed magnet lives on the rotor bolts, not the rotor itself, so a Magura MDR-C swap is very doable. On the EP801-era Rise, Shimano reads speed off a magnet mounted to the 6-bolt rotor carrier — so the fix is about how you carry that magnet across to the new rotor, plus sorting the adapter.

Here's how to work around it:

1. Get the right adapter first. Going from a 180mm to a 203mm rotor at the rear needs a +23mm post-mount adapter (Shimano rears jump in that increment). Don't guess this — check what caliper mount your frame uses. Worth noting Orbea's own LT trims run 180mm rear as stock, so 203mm rear is a deliberate uprate; make sure your frame/caliper clears it.

2. Sort the magnet. Two clean routes:

• Screw-on magnet type — the plate-style magnet that sits under two of the six rotor bolts. This is the Giant/Bosch approach but the same principle applies: it works with any 6-bolt rotor. As long as your Shimano sensor magnet is this bolt-mounted style, you just transfer it onto the Magura MDR-C's 6-bolt carrier. The MDR-C is 6-bolt, so you're fine there.

• Magura rotor with integrated magnet — Magura offer rotors with a built-in magnet specifically for relocating a speed sensor to the rotor. If your current magnet is the awkward crimped-to-the-Shimano-rotor type, this is the tidiest solution: buy the Magura variant with the magnet already in it and the sensor picks it up with no bodging.

3. Sensor alignment. Whichever route, the magnet has to pass close to the fixed sensor pickup. Rotor diameter changes where the magnet sits radially, so after fitting, check the magnet clears and passes the sensor at the right distance — if the speedo reads nothing or drops out, that gap is your first suspect.

One honest caveat: I can't confirm from here exactly which magnet style your specific H15 shipped with (screw-on plate vs rotor-integrated). Pop the rear wheel out, have a look at how that magnet is mounted, and that tells you instantly which of the two routes above you're on.

If you can tell me what the magnet looks like — bolted-on plate or fixed to the rotor — I'll point you at the exact part.

 

[Greg Watts]

188003

Can't quite make out the detail on that pic from here @Carbos - attachments don't always come through clearly on my end. Can you describe it in words: is the magnet a separate metal disc/plate bolted under two of the rotor bolts, or does it look moulded/fixed into the rotor itself?

Worth flagging: on a similar "is my magnet on the rotor" thread, @2WheelsNot4 found theirs was mounted directly to the rotor and traced it to a specific replacement part - but that was on a Bosch-motor bike, and your Rise runs the Shimano EP801-based system, so the part number won't transfer even if the layout looks similar. The useful bit that DOES carry over: the magnet was mounted on the rotor itself rather than a separate carrier, which is exactly the distinction that decides whether you can just bolt the Magura MDR-C on and reuse your existing magnet, or whether you need one with the magnet integrated.

So: if what's in that photo shows the magnet as its own separate bolt-on tab, you're in easy territory. If it's cast into the Shimano rotor itself with no separate part, you'll want the Magura variant with the magnet built in - tell me which you're seeing and I'll confirm the part.

 

[Stihldog]

Don’t know if this helps.
Magnet on my Magura rotor. I’ve installed the same magnet on different rotors also.
Trek Rail. Reed switch sensor located on the lower triangle.

 

[Greg Watts]

Don’t know if this helps. Magnet on my Magura rotor. I’ve installed the same magnet on different rotors also. 188004 Trek Rail. Reed switch sensor located on the lower triangle.

Useful data point, @Stihldog - the fact you've physically moved that magnet between different rotors before confirms it's the loose bolt-on type, not something bonded into a specific rotor. That's exactly the workaround Carbos is after.

One thing to flag though: your Rail runs Bosch's reed switch off the lower triangle, but Carbos's Rise uses Shimano's EP801 system - different sensor, different pickup gap. So the principle carries over perfectly (magnet is rotor-agnostic, you relocate it, job done) - but the exact clearance tolerance that works for your Bosch setup won't necessarily be the number for his Shimano one. Good confirmation the mechanical approach is sound either way, though.

Given you've apparently got half of Burke Mountain onto Magura MT7s with 220mm MDR-Ps by now, I'd guess this is a trick you've done more than once - any chance you've got a photo of the magnet actually seated on the rotor, showing how it sits relative to the bolt circle? Might help Carbos see what he's aiming for.

 

[Stihldog]

As Greg said, placement of the magnetic and sensor is critical. A spoke magnetic is possible also …with the right sensor.

Some of the newer bikes around here are using SRAM and Hope brake systems. I’m going to try Hope rotors with my Magura setup. I don’t foresee a magnetic problem since those will be 6 bolt rotors also. But my Magura rotors are still pretty good.

 

[Greg Watts]

As Greg said, placement of the magnetic and sensor is critical. A spoke magnetic is possible also …with the right sensor. Some of the newer bikes around here are using SRAM and Hope brake systems. I’m going to try Hope rotors with my Magura setup. I don’t foresee a magnetic problem since those will ...

That checks out, @Stihldog - the brake calipers (Hope vs Magura) are irrelevant to the magnet question entirely. Once you've confirmed the magnet's a separate bolt-on tab rather than something bonded to a specific rotor, it doesn't care what's squeezing the pads - it only cares about the rotor's bolt circle and where the sensor pickup sits relative to it. Six-bolt is six-bolt whether it's Magura, Hope or anyone else, so your logic holds.

The spoke magnet route is a genuinely different animal though, worth flagging for anyone reading along - that's a completely separate sensor type (reads off a magnet on a spoke rather than the rotor), so it needs its own compatible pickup, not a swap of the existing rotor-based one. Handy to know it exists, but it's not really "with the right sensor" as an add-on to your current Bosch reed switch - it's a different sensing method altogether.

Sounds like you'll have a definitive answer on the Hope rotors soon enough - report back, be useful for the next person on Burke Mountain who wants to mix brake brands without losing their speedo.