Mountain Bike Power meter - SOLUTION FOUND

[Hodders]

I want to fit a power meter and don't want to spend silly money....

I like flat pedals so that rules out that option as I'm not paying silly money for the SRAM ones.

Left hand crank arm is an option except there is only about 5mm clearance between the crank-arm and the rear suspension chain stay arm.

Spider would be tidy except my understanding is that the Hollowtech crank has a non-removable spider even if the chainring is changeable.

Any suggestions?

 

[SoliD]

Fairly limited with your strict criteria, stages if it fits is probably your only option unless you get a powertap wheel.

 

[Saytan]

4iii also do an MTB crank power meter in XT and XTR. Sounds like you may struggle for clearance though.

 

[Hodders]

Frustratingly - the 4iiii *almost* would fit but the AAA battery *just* touches the rear suspension arm.

Looking at the Sigeyi powermeter that seems to be pretty decent. https://www.sigeyishop.com/product/axo-power-meter-for-shimano-mtb/

It looks like it will fit my crank but will need a chainring.

Now I can take the one off my existing crack - its a 8-100BCD fit.

But the key question......

Is the 8-100BCD the new standard Shimano chainring pattern or is it 4-104BCD ?

 

[Hodders]

In an attempt to answer my own question it appears as though:

The 8 bolt 100BCD chain ring is only made by Shimano as part of a direct mount chainring so basically you have to buy the whole replacement chainring (inc direct mount spider) to get the chainring itself.

Looks like the 4 bolt 104BCD is pretty much the aftermarket standard with options from Hope, Wolftooth etc. Seems like that is the way to go.

Can anyone confirm?

 

[Hodders]

Ended up buying a Sigeyi power meter. Comes in 104BCD or 100 for shimano 8 bolt.

Ended up taking a SLX m8100 32t chainring of its direct mount spider and fitting it.

Fits really well, chain line is exactly the same.

GPlama does a review here.... https://youtu.be/hv5JhlveWv8

 

[Hodders]

Few rides out now. Works really well. Syncs with my garmin, feeds into strava.

The App shows L/R balance, but this is not reflected into garmin or strava. Not too fussed as it has no idea if I am using flats of clip ins.

Great option.

 

[fez]

L/R balance is just a complete guess isn't it unless you have a dual sided PM. Flats and clips shouldn't make any difference either.

 

[robj20]

I was really considering the new SRAM Transmission cranks for the spindle power, looked a great idea.
But considering 99% of my training is done on the what trainer I can suffice with that last 1% being just Heart Rate based.