PM Adapter frustrations

[Jeffsy29]

Magura Caliper adapter needed upgrading from 160 PM on Orbea Vibe

I know the Vibe isn't an mtb, but hopefully some of you folks with Magura experience might know the answer. The Vibe is Orbea's urban bike and comes with a post-mount caliper and 160mm Magura rotor. A little weak for my mass. I'm looking to upgrade to 180 or even 203mm, if possible.

The fork comes with the QM 40 adapter already installed to accommodate a 160mm diameter rotor. But looking at Magura's chart, it implies that adapter would take you from 160 to 180 mm. If QM 40 is required just to get to reach 160mm, I'm wondering what's needed even to get to 180mm?

The chart is confusing as it recommends QM 42 for 160->203mm, but that can't be the case if QM 40 only gets me to 160mm. Is 203mm out of the question given this chart of adapters? Does anyone 'piggyback' adapters to get from 160-203mm or is that just sketchy?

Can anyone make sense of this chart, and would I use QM 42 for a 180mm rotor?

 

[Spangoolies]

By the sounds of it your forks are pm120 so designed for a 120mm rotor without any adaptors. Problem is the chart doesn’t go that small. You’re looking at a front +60mm pm to pm adaptor. I would be checking with the fork manufacturer if your forks can safely take an increase of that much.
Double adaptor is very sketchy.

Edit: I read the table wrong. The numbers on the adaptors do not relate to the size increase.

 

[Jeffsy29]

By the sounds of it your forks are pm120 so designed for a 120mm rotor without any adaptors. Problem is the chart doesn’t go that small. You’re looking at a front +60mm pm to pm adaptor. I would be checking with the fork manufacturer if your forks can safely take an increase of that much

@Spangoolies - I'm assuming the mfg. is Orbea...they call it "Orbea Vibe Carbon Fork" on the spec. sheet. I guess I'll try their tech support. I didn't think about fork strength as a limiting factor but I suppose the torque has to come from somewhere.

 

[Spangoolies]

Sorry, just looked into this further, strangely the qm40 is only a +20mm adaptor so your forks are 140mm rotor size standard. Adding 40mm shouldn't be too bad but best to check if you can as they are carbon road/hybrid forks. Also the vibes that I’m looking at says that the forks are flat mount? but that doesn’t make any sense as the qm40 adaptor that you have is post mount to post mount and they look like post mount fittings in your picture. Different model vibe to the ones I’m looking at maybe? So by the sounds of it all you need is a magura qm45 adaptor as that looks to increase by 40mm and is the same fitment as the one you already have

 

[Jeffsy29]

Sorry, just looked into this further, strangely the qm40 is only a +20mm adaptor so your forks are 140mm rotor size standard. Adding 40mm shouldn't be too bad but best to check if you can as they are carbon road/hybrid forks. Also the vibes that I’m looking at says that the forks are flat mount? but that doesn’t make any sense as the qm40 adaptor that you have is post mount to post mount and they look like post mount fittings in your picture. Different model vibe to the ones I’m looking at maybe? So by the sounds of it all you need is a magura qm45 adaptor as that looks to increase by 40mm and is the same fitment as the one you already have

Indeed the specs seem to be incorrect.

Worse still, this review claims it comes with 220mm rotors! Overkill for most folks for street use....

I've reached out to Orbea Support to see if they can verify 1) is it possible to do 180 safely and 2) if so, what adaptor.