Sub-compact power meter options?

[Ulver]

Frustratingly limited options for one of my niche bikes...!

It is a Condor touring bike. It is steel and very classic looking. I use SPD shoes, it runs 650b wheels with discs and has a BSA bottom bracket. This seems to strike out all pedal based options. I have a super low 44-28 classic Rene Herse style crankset so no crank arm options either. The wheels are built with Grand Bois 32 hole rims with a Son Delux dynamo up front and a polished silver finish.

The reason I want power on this bike is that I do long multi day rides and want to a) keep better track of fatigue and b) pace myself better as when loaded up it is very easy to go a bit too hard as the pace is lower.

Only options I can think are either:
1. Powertap disc hub (https://www.powertap.com/product/powertap-disc-hub) which seems fairly sensible as I will only ever be using those wheels on that bike and with it being discs the rims won't be wearing out anytime soon. Also I'd get to keep the awesome looking crankset. The hub is heavy but then so is the bike so again not an issue. Downsides seem to be that a) it is ugly and won't match the rest of the bike and b) the disc brake rim appears to be proprietary which probably isn't a big issue but could be on a random adventure somewhere. Other positive is that I use a Powertap on my main training bike so would be consistent.
2. Hope that FSA extends its Powerbox range to its new sub compact sets. Would be fine with 46-30. (Ugly though, more so than a hub).
3. Are there any existing 'sub-compact' sets out there that can take a crank arm power meter like Stages/4iii that work with BSA bottom brackets? Alternatively it looks like Rotor's new No Q direct mount chain ring matched to one of their power meters is one option (http://www.velotechservices.co.uk/shop/ ... 49&cat=373). I am slightly confused as to which crankset I'd pair it with though. Again generally ugly/doesn't fit classic looks.

Frustrating that nobody does an SPD pedal based power meter (not everybody using SPDs is smashing them into rocks all day long!).

Any suggestions very welcome.

[rheosibal]

Not sure if it'll work with your crankset, but this might work: http://watteam.com/off-road/

I'd pair this with the newer white industries cranks if possible. You could hypothetically get the same gearing as well with the vbc chainrings.

[kulivontot]

Since spd is only Shimano and Shimano do not have a released power meter (pedal or otherwise) somehow I'm not surprised?
If the problem is gearing range, why not use any hollowtech mtb or road triple crank and a stages left crankarm?
But honestly power tap makes the most sense as the weight penalty and 32H requirement is almost meaningless for a touring rig where you're not going to run a 24H lightweight rear wheel anyway.
I've got to say the market overlap for wide range double touring cranksets and high accuracy power meters is pretty much zero.

[synthesis]

Seems like a Powerpod is your best bet. http://www.powerpodsports.com/

[Ulver]

Since spd is only Shimano and Shimano do not have a released power meter (pedal or otherwise) somehow I'm not surprised?
If the problem is gearing range, why not use any hollowtech mtb or road triple crank and a stages left crankarm?
But honestly power tap makes the most sense as the weight penalty and 32H requirement is almost meaningless for a touring rig where you're not going to run a 24H lightweight rear wheel anyway.
I've got to say the market overlap for wide range double touring cranksets and high accuracy power meters is pretty much zero.

You are probably right but I wonder if the emerging popularity of more serious gravel / multi long day adventure racing might lead to demand for gearing that crosses into touring territory. When I say SPD I would happily use any two hole format with recessed cleats. Shimano have actually launched a crankset based power meter, not sure if it is on sale yet.

I had a triple on the bike originally but hated it. Way too much shifting on the front ring.

I'll likely go Powetap but was just intrigued to see if I had missed any other interesting options especially as the specificity of that wheelset means I wouldn't be able to use it on another bike whearas some of the other options can potentially be moved.

[Ulver]

Seems like a Powerpod is your best bet. http://www.powerpodsports.com/

I forgot to mention Powerpod. It seems like a really interesting idea and also considerably cheaper than other options. You will laugh but I am waiting on delivery of a Gilles Berthoud handlebar bag - I then need to measure up to see if there would be space to mount a Powerpod. Potentially it could mount on the front rack but that might flex too much. (You can see how frustrating this process is).

Here is the bike in question. I will be putting wider tyres on it hence the non-finalised fenders.

[silvalis]

Frustrating that nobody does an SPD pedal based power meter (not everybody using SPDs is smashing them into rocks all day long!).

Any suggestions very welcome.

you can get conversion kits from garmin to fit a vector2 into a ultegra 6800 pedal

[mattr]

Ultegra 6800 isn't spd.

Could you not get an xt double with aftermarket rings and stages LH crank.

[Ulver]

Ultegra 6800 isn't spd.

Could you not get an xt double with aftermarket rings and stages LH crank.

Potentially a winner, the issues I see are mainly Q factor (not super bothered) but also they're all 96 BCD I think and I'm not sure if you can get anything bigger than a 38t?

EDIT: Looks like the XTR M980/985 is the one.. 104/64 BCD, can be had in something like a 42/30 for around £200 + around £500 for Stages.

As long as I can stomach losing the classis style of the existing crankset then this could well be the option.

Cheers!

[mattr]

Get an xt double in silver and give it a bit of elbow grease. Won't look ideal. But at least it'll be shiny.

[silvalis]

oops. glanced at the picture and thought it was one of those silver spdsl pedals.