MTB double chain spider based ring power meter

[maslow]

As per the title. Is there such a thing. Feel free to laugh but I’m still riding mtb doubles (and triples on my 26”).

Bit of an experiment but I’d like to fit MTB gears on a bike packing rig with a close ratio cassette. I can see that power2max do SRAM and FSA afterburn MTB double options but im looking to keep a road q-factor. I realise there’s the option of P2M gravel power meter but they only do two chain ring options (48:31 and 46/30). Looking for ability to run slightly smaller chainrings

[djg21]

Originally Posted by maslow

As per the title. Is there such a thing. Feel free to laugh but I’m still riding mtb doubles (and triples on my 26”).

Bit of an experiment but I’d like to fit MTB gears on a bike packing rig with a close ratio cassette. I can see that power2max do SRAM and FSA afterburn MTB double options but im looking to keep a road q-factor. I realise there’s the option of P2M gravel power meter but they only do two chain ring options (48:31 and 46/30). Looking for ability to run slightly smaller chainrings

You can use SRAM Force AXS 2x crank and power meter with an Eagle RD. You’d be limited to 46/30 rings, but can use an Eagle MTB cassette.

[Mark McM]

Originally Posted by maslow

As per the title. Is there such a thing. Feel free to laugh but I’m still riding mtb doubles (and triples on my 26”).

Bit of an experiment but I’d like to fit MTB gears on a bike packing rig with a close ratio cassette. I can see that power2max do SRAM and FSA afterburn MTB double options but im looking to keep a road q-factor. I realise there’s the option of P2M gravel power meter but they only do two chain ring options (48:31 and 46/30). Looking for ability to run slightly smaller chainrings

Q factor is a function of the crank, not the power meter. If you install an MTB power meter spider on a road crank, it will have a road crank Q factor and road crank chainline. I've used several MTB/gravel spiders on road cranks to produce road Q factors and chainlines.

[Mark McM]

Originally Posted by maslow

I realise there’s the option of P2M gravel power meter but they only do two chain ring options (48:31 and 46/30). Looking for ability to run slightlysmaller chainrings

In regard to P2M gravel power meters: P2M has two different types of gravel power meters: A spider with a 104mm BCD, to which is mounted a proprietary CNC'ed integrated double chainring (48/31 or 46/30); and a spider with 110mm/80mm BCDs that is compatible for mounting Shimano GRX chainrings. Although Shimano only makes 48/31 and 46/30 GRX chainrings, aftermarket manufacturers such as TA makes GRX compatible chainrings down to 44/28. The P2M GRX spider is only compatible with Rotor Aldhu cranks. Rotor makes two different interchangeable Aldhu spindles - a "wide" spindle which produces a 152mm Q factor and 46 chainline, and "standard" spindle which produces a 147mm Q factor and 43.5mm chainline.

[ColonelJLloyd]

I have a new SRAM X01(?) spider with 42/28 rings I've been hoarding. Had plans to mount it to Force22 arms. I guess you'd need a left-arm (Stages?) PM for that setup. I'm not well versed in PMs.

[maslow]

Originally Posted by Mark McM

In regard to P2M gravel power meters: P2M has two different types of gravel power meters: A spider with a 104mm BCD, to which is mounted a proprietary CNC'ed integrated double chainring (48/31 or 46/30); and a spider with 110mm/80mm BCDs that is compatible for mounting Shimano GRX chainrings. Although Shimano only makes 48/31 and 46/30 GRX chainrings, aftermarket manufacturers such as TA makes GRX compatible chainrings down to 44/28. The P2M GRX spider is only compatible with Rotor Aldhu cranks. Rotor makes two different interchangeable Aldhu spindles - a "wide" spindle which produces a 152mm Q factor and 46 chainline, and "standard" spindle which produces a 147mm Q factor and 43.5mm chainline.

Thanks — that GRX chain ring compatible unit from P2M might work. I’ve already got Aldu cranks hence my first thought was their NGeco unit with the 104 bcd proprietary chainring.

[maslow]

Originally Posted by ColonelJLloyd

I have a new SRAM X01(?) spider with 42/28 rings I've been hoarding. Had plans to mount it to Force22 arms. I guess you'd need a left-arm (Stages?) PM for that setup. I'm not well versed in PMs.

Thanks for the offer but ideally want a spider based meter.

[KonaSS]

Power pedals might be your best bet. Allows you to use whatever drivetrain you want to use.

[benb]

I think I'm reluctant to think about pedal power meters since you're way more likely to smash them into a rock on a MTB but you gotta admit if you really want this the pedal PMs make some sense.