lhbernhardt

Any of you experts here have any recommendations? I'm looking for a crank-based power meter for use on the track, since I don't want to be tied to using just one wheel (I realize the easy solution for track is a hub-based power meter like a PowerTap, but even that would require a bit of tweaking). And SRM is too expensive to be in the equation.

Ideally, the unit would work with a Shimano external bb, as this has the best method of crank attachment (I've used SRAM with the Omnium, and it leaves a lot to be desired). But then I'd have to switch to 130mm bcd rings, but Gebhardt makes 1/8" track chainrings in al sizes. The solution I'm looking at now is a Power2max on 165mm Rotor 3D cranks, but I'm concerned about the chainline. I want to be able to use a standard track rear hub, and all the crank-based power meters I've seen assume you're using road stuff.

Anyone here have any experience or recommendations? Thanks.

Luis

Dalai

I've read (either here or fixedgearfever) that some have used Quarq's. Either 130 bcd or using a custom made adapter plate on a 110 bcd crank that allows them to use 144 bcd chain rings... Haven't heard of anyone using a Power2max.

Perhaps try posting the question on the wattage google group?

carleton

SRM is pretty much it.

Look for used sets. You can replace the crank arms for $200 if the used set doesn't have the length you need.

It's not a perfect system (no user-replaceable batteries)...but it's the best available now for track.

Kayce

A few years ago at NAHBBS I saw a pedal based power system. I have no idea who was working on it or if anything came out of it, but maybe look into that.

Nagrom_

It was LOOK iirc.

Soil_Sampler

https://sites.garmin.com/vector/#power

there is more than one system...

Nagrom_

https://www.lookcycle.com/en/us/route...keo-power.html

There's LOOK's system.

Dalai

The issue with pedal based PM's is the fact only one actually exists (the Look pedals) and even that has been a very limited release with a number of issues. The Vector has had the release date pushed back for at least a couple of years now...

There are quite a few groups trying to measure power at the pedal and only the Look has made it to market. Others include Brim Brothers cleat system https://www.brimbrothers.com/ and an Australian system https://www.bikepowerpedals.com/ but with no photos that I've only just heard about.

For crank options, it may be worthwhile considering the Stage One model with a couple of caveats - only very new so you would be a beta tester, plus it only measures one leg and just assumes you are balanced. They do have a 7710 crank arm available in their range - at this time they can't be fitted to carbon arms https://www.stagescycling.com/stageone-models

Personally I'd looked for a second hand wired SRM. I have three wired SRM's (SRM Pro on the road bike, FSA SRM on the TT bike and SRM track swapped between my training and race track bikes). They were all bought second hand and all working flawlessly.

carleton

There are LOTS of proposed power meter systems out there because the Triathletes will buy them. They have lots of money. Most of which never make it to market. Of the ones that DO actually make it to market, only one is made for track...SRM.

PowerTap does some funky interpolation of the data as it actually samples at over 1 per second.

The pedal systems can't make it out of testing.

You guys can listen to the marketing speak and hold out and wait for the pedal/shoe based systems if you want. But, if it's taking this long for them to make it to market, you'd best believe that the first generation that does will be very buggy.

SRM has been around for a LONG time. If you need a power meter now (not 2 or more years from now) find one.

On the other hand, power meters aren't really necessary. A computer that tracks speed and cadence data for download and analysis will do 95% of what you'd use a power meter for. I've had an SRM for 3 full seasons and I evaluate Speed and Cadence data waaaaay more than power.

queerpunk

A friend of mine is the one who makes the 110->144 adaptor plates for Quarq. They work really well and even with the cost of the plate+Quarq, comes out cheaper than a track SRM.

Here's FGF chatter about it:
https://www.fixedgearfever.com/module...er=asc&start=0

Nagrom_

Found something in the 41 and remembered this thread.

https://www.dcrainmaker.com/2012/11/1...wer-meter.html

https://www.bikeforums.net/showthread...ter-(with-pics!)


Might be a solution?

carleton

The best paragraph in his review:

There are so many that are proposed...that will never be anything but prototypes.

Nagrom_

Absolutely. All of these other solutions have been in the works for quite a while too, and have yet to catch on. Says something.

Also just noticed the one I just linked only works for speedplay pedals, which don't seem to be very popular on the track.

carleton

The one you linked to does not exist as a finished product It's only a prototype. There may only be a handful in existence.

Pantani98

Just to bring this back up as I saw this in one of my mountain bike mags. I know SRM is the ticket, but just to add something else to the mix... https://store.nexternal.com/stages/st...-track-p9.aspx

carleton

Wow. That's interesting. I'd heard of it before, but I didn't know they had a track version.

My ONLY gripe is that it only records from one leg and interpolates (guesses) what the other leg is doing. I'm not sure if I'd use it for sprint work. Maybe TTs it would be OK.

Nagrom_

Also only goes up to 2k watts. I doubt it will be an issue for many, but i'm sure someone who can break that would be a little disappointed to see their power graph plateau.

The price isn't too bad though.

Dalai

I mentioned all the above (Stages / Brim Brothers) on the 16th...

Pantani98

Doh! Yes you did. That will teach me to speed read (scan). I just wanted to mention it again in case anyone (me) missed it. Haha!!!

Nagrom_

Hey guys, stumbled upon a 110-144BCD converter while browsing for other things, and remembered this thread yet again. This seems much more readily available than the custom made one mentioned here.
https://www.bdopcycling.com/Track%20P...p#TRACKADAPTOR

Hida Yanra

BDop is good people - and he says he has a 130-144 adaptor drawn up that he says he hopes to have available (as in, buyable and usable, in the flesh) in the near-ish future.

Nagrom_

BDop is great people. Sells great products for great prices and has the fastest shipping from Taiwan I've ever seen.

carleton

+1

He's also a bikeforums member. He's active on the Road and Road Racing forums.

https://www.bikeforums.net/member.php/87367-Bob-Dopolina

His blog: https://oldguyracer.blogspot.com/

Racer Ex 

I run a Rotor 3D+ BB30 SRM with 130 BCD Miche 1/8 track rings; I set it up with a shaved down small ring with the chain rings nuts epoxied in; very quick and easy ring changes. Rotor makes a "plug and play" EXO threaded bottom bracket that will allow BB30 for some units in a standard BB shell.

Unless you're a Chris Hoy 2000w guy you're not going to have an issue at 130 vs. 144 with flex, especially if you go BB30, so road SRM's are an option without an adapter. You probably won't be able to borrow rings at the track though. 1/8" 130 BCD rings are out there from cheap (Vuelta) to a bit pricey (Miche, but they weren't that bad through Ribble int he UK and they are really well made).

Only certain road SRM's will work for this application, contingent on the meter/crank interface (7800/7900 Dura Ace for instance are "no go"). And only a few come available with 165 arms.

Quarq is a very poor solution; they recommend calibration when changing rings and I'd be very leery with the back pressure sending those units into a tizzy. I think around 90% of the folks I know have had to send units back, some as many as four.

The pedal stuff is vaporware other than Look, and they have more than a few teething problems and customer support problems.

Stages is cataloging a Dura Ace track model. Which means a big "maybe". They have zero of anything purchasable right now, the road units that are out there are beta and buggy and I would guess that their production focus is going to be on what they have the most pre-order's on. That said if they do get it up and running, and reliable, it would be the cheap alternative to SRM.

But that's a lot of ifs.

Dalai

I've read road SRM Professional cranks always don't like being used fixed - can't recall exactly why though.

Track SRM's do come up for sale infrequently. I bought mine on fleabay - thankfully many times when marked as for sale in the US only people will send OS if asked.