Updated: Taipei Cycle: Xpedo to launch power meter

KnightBiker wrote:

@ david arthur - yes it doesn't happen that often, but it does happen. Product like speedplay even promote their pedals with exactly that argument of having a low height.

Is that not in relation to stack height though - the height the foot is above the pedal axle - and not in relation to the risk of clipping the road going round a corner?

Jimmy Ray Will wrote:

...you are likely to be generating significant force on the upstroke

Seriously?

Jimmy Ray Will wrote:

My fear is the same as others... that this will present cornering challenges.

Not proper corners but on exit when starting to pedal again. Now we've all done it, and the fact is, you'll be doing it more in these pedals. I would suggest a revised design should place as much of the 'junk', towards the crank side of the pedal and away from that trailing edge.

That said, this design is particularly interesting to me, as we are one step closer to what I think will ultimately be the power answer. The fact that the power measurement is taking place directly under the cleat is great as well....

However.... does it manage to calculate 'pull' as well as 'push'? When riding normally this will not be relevant, but in a max sprint or a 30sec effort, you are likely to be generating significant force on the upstroke... which will be missed in a system that simply measure compression forces.

Moving stuff to the crank side presents clearance issues, which was the same challenge faced by the Vector team. In fact the Garmin solution has been equally criticised for pedal clearance owing to the pod positioning. Which you prefer is a personal thing, but I'd guess that the Garmin pod would shear off more easily than the design shown here. Obviously everything comes down to individual crash dynamics, but if you assume the pedal does make contact it could boil down to $150 for a replacement pod vs $x for a replacement powermeter and patching yourself up after a big off.

I've been running the Vectors for months now and not observed any issue - but with conventional aggressive cornering the inside pedal is at 12 'o' clock anyway and I'm not a crit racer.

With regards the manner in which the forces are recorded, strain gauges are multi-axial rosettes build into the spindle - capable of measuring any input (even non-planar). The greatest limiter in many respects comes down to sample rate and having the resolution to generate meaningful data - and then having a defined protocol for communicating it. The new Pioneer system has made a few steps forward in that area.

EDIT to add: It would appear the xpedo uses a sensor on the pedal contact surface, not in the spindle. This makes them less "capable" than the Vector solution from a hardware POV - but you pay your money and take your choice I guess.

themartincox wrote:

how's it pronounced? might want to have a word with marketing before i pop out for a set of 'pedos

In the pub: "You're a fan of ex-paedos? Reeeaallly?!"

KnightBiker wrote:

It looks to me as if this thing will easily touch the ground when cornering, the pedal's height seems almost twice of normal shimano race pedals.

It's extremely rare to clip a pedal on the road through a bend, and usually only happens when you get back on the power too soon out of the corner. It's something I've only ever done once or twice ever, and both occasions were in crit races - I didn't make the same mistake again

Really interesting product development though, looks better packaged than the Garmin system and is probably easier to setup as well. Impressed they managed to keep it such a secret too until the launch

KnightBiker wrote:

It looks to me as if this thing will easily touch the ground when cornering, the pedal's height seems almost twice of normal shimano race pedals.

With all the extra gubbins I can't even work out how you attach your shoe - does the pic include a custom cleat already clipped in?

EDIT: Additional pics now make it a lot clearer!