Having spent months on Zwift in the garage I’m now pathetically trapped in a perceived need to know my power output while cycling, and I’d like to get a power meter for my Camino with Force 1 GXP cranks. I know I don’t need this, and that Strava provides estimated power, but I’m a nerd.

The best option seems to be a factory fit single sided 4iiii meter ($299) as it’s much cheaper than a Stages left crank arm (£455).I’m fine with single sided, and it needs (1) not to be too expensive and (2) to work on SPDs so none of the pedal-based options work. The new Garmin SPD ones that came out yesterday are silly money. 4iiii have a distributor in the UK but they won’t be able to fit power meters to customer cranks until at least the summer.

If I send my left crank arm to 4iiii in Canada it’ll be gone for at least three weeks so I’m thinking of looking for a second hand one on eBay that I could use while its gone, but I’m a total numpty when it comes to SRAM cranks. Are the left crank arms interchangeable between groupsets? Anything else I need to know about compatibility?

And has anyone bought anything from Canada recently? The other concerns of course getting stung on VAT, duty, and other import charges.

Many thanks!

I’m now pathetically trapped in a perceived need to know my power output while cycling, and I’d like to get a power meter for my Camino with Force 1 GXP cranks. I know I don’t need this, and that Strava provides estimated power, but I’m a nerd.

FWIW if you’ve got a Zwift setup then it’ll be far easier to do any structured power based training on that as it’s pretty hard to hold a steady 200/250 whatever on a real ride. As a result power figures from a real ride will most likely look very different from your Zwift figures so you’ll be left reconciling the difference anyway, so might as well rely on Strava power which we all know is a massive underestimate for your own rides 😉 That way ypu’ve still got a bike to ride and have saved a pocketful of cash to spend on cake, bike stuff or cake. But if you’re just a numbers nerd all of this means nothing, not even the cake bit.

I’ve been really pleased with my 4iii power meter, I looked at sending the existing arm off but in the end I found it cost me about 20 quid more to just buy a complete one, and that way I have a spare if the power meter needs to be sent back. I seem to remember the sending it off option looked a lot less attractive once you accounted for postage, than it at first appeared…

oh and you will get stung on vat and import duty from canada, they’re really hot on it. every time I’ve bought stuff from there I’ve been charged, puts me right off ordering form sparrows 🙂

What a hassle. I appreciate you are restricted by the Force groupset and gxp bb though.

What chainrings/crank length do you currently ride? Have you considered buying something used on ebay? There’s a red/quarq (53-39, 175mm) for £299 (or make an offer) now, gxp. Straight swap, sell your force cranks, and you’ve got a better, dual sided setup for a similar spend.

If you want compact or different crank lengths you’d need patience. A completed listings search would give you a clue how much. Price is probably a good indication though.

Thanks all. @thepurist you are of course right, but it’s more about tracking my (hopefully!) improving fitness than being able to match ergo mode while out in the real world. I was in a terrible work from home sedentariness rut up to the end of last year that I have turned round completely since Christmas day, and the nerd in me finds the numbers a major incentive tool.

@mahowlett and @savoyad – I guess you’re both right, and thanks for the warning on the duty! I would happily buy a ready-made crank arm in the UK but no one seems to do them for SRAM cranks. I missed out on this Stages left crank arm on eBay last night, but I could just get those Red/Quark cranks (presumably this listing) or similar and stick a 40t narrow-wide changing on to make them 1x…

…on reflection I’d probably be better off making my old 105 cranks 1x and getting a left hand crank arm off eBay – there seem to be loads of Shimano left crank arm power meters on there. Thanks for making me reconsider – I’ll give it some thought.

I’m currently running a quarq sram red on my Pickenflick. I have a 42t Sram Chainring on there or a 40t Hope retainer, depending what a race is like. They’re fine and the power meter is a damn site more reliable than my vector 3’s on the road bike (although touch wood they’ve been fine the last 3 months!)

That was my GXP on ebay last night!

I’ve sold all my Stages and replaced them a set of Assioma Duo’s. Why not look at the Assioma Uno if you’re not bothered about dual sided? They pop up on eBay regularly and are easily converted to SPD

Looked at these?

https://www.power2max.com/en/power-meter-ngeco-road/

Gets an excellent DCR review, and you’d have essentially zero downtime.

(For those that mention pedlas – not keen on pedals for an off road bike myself – pedal strikes can’t be good for the electronics, strain gauges etc in a pedal.)

Lorax, for what it’s worth I’ve recently got a 4iiii 105 left hand and it’s been great so far. I’ve found it useful on the road and on the trainer too. Think I paid £240 from Winstanleys.

@r8jimbob88 Blimey, you did well – that went for not much less than a new one. You owe me for my bid 10 seconds before the end that pushed the price right up 🙂

@branes – that Ngeco power meter looks good but it appears that there may be a long wait for the SRAM 110 BCD version. I’ll email them to check though.

It’s increasingly looking as if I should swap over my Force1 cranks for my old 105s. A shame it’s so hard to do this with SRAM!

Hi @lorax I hadn’t appreciated the 1x – so I don’t know which spider PMs would be compatible. If you are open to swapping over to 105 things do get a lot simpler on the crank front though.

Thanks @savoyad. I’m assuming I can just stick a single chainring on my Shimano cranks and run them as 1x, but need to make sure this won’t cause a problem with chainline. I’ll investigate.

Grrr – I’ve now checked both my SRAM 1x and Ultegra cranks for clearance using the advice on both the Stages and 4iiii websites and it turns out my frame is too tight for either! There will now be duty to pay on an NGeco spider, so I’m now looking at a second hand Rotor crankset on eBay, and will just have to hope the chainline’s okay.

You could look at the Avio powersense. They’re UK based and relatively cheap but it certainly looks to be a bit of a gamble.

Thanks @Gribs – certainly cheap compared to the others, but the clearance is also too tight for them https://avio-sports.myshopify.com/pages/clearance

(and a mixed picture of reviews…)

Cautionary tale – I am having to go through all forums to denounce 4iiii in hopes they will answer my emails, but let it be an example of their customer support if you decide to go with them

– I have a Stages dual sided powermeter on Ultegra cranks that I bought off the shelf, and have been very happy with it – no connection drops, no weird power readings. Wanting to have a crank based powermeter in my other bike, I checked and saw that Stages don’t do factory installs on FSA cranks (I like the FSA carbon cranks I have on that bike and wanted to keep them) but 4iiii do 
– Checked on their webpage and my FSA K-light are listed as compatible – so I sent the required emails with the model, the photos checking clearance to frame and sent the left crank for the factory install
– 10 days later, I start to wonder why the crank is still in the scheduled installation/installation phase – so I write an email and get a response saying the crank is not compatible for a Precision factory install and that I will be refunded
– I am pretty annoyed at this point, as it has taken them 10 days to check the crank and see that it is not compatible (BS, as they still show FSA as compatible in their site), but ok, I ask why is it not compatible and when will I get my crank back
– No response (although they did refund the money, thank God) on either of the two points: so I start calling, sending emails and finally, I have to resort to public shaming in the hopes they will return my frigging crank. Still no sign of my crank btw.
– So I cannot speak on how their powermeters work, but I can say that their customer service is non-existent and they will leave you to rot if tyou have an issue, so I’d honestly give them a pass based on my experience.

I had an issue with my 4iiii crank and they were pretty quick to run through options then say it needed replaced, they supplied ticket number and it was easy then to deal with the shop I bought them from. Power meters do seem to be a thing that suffer from issues though so not sure I would buy second hand.