Power Meters / Powermeters (SRM, Powertap, Quarq, Ergomo, Vector, Stages, power2max, P2M, 4iii, InPower, Cinch)

As it's your first one you would probably get a more accurate result doing a MAP ramp test as pacing doesn't come into play.

Is that likely to give accurate results if outside though?

You can’t do a ramp test outside/without a turbo.

For a 20 minute outside test just hit the lap button when ready and again when finished.

I suspect you’ll struggle a bit to get an accurate result first time though, especially outside.

Yep, I thought I'd read that.

Ok sure, thanks. Will see how it goes.

And from them to SRM in Germany.

Got it back today. Apparently needed a firmware update, seems to be working fine now. Also only charged me £25 and gave me a 2 year warranty, which is fairly decent of them seeing as I'm at least the third owner of it. Impressed.*

*Until it fucks up again.

My Powertap P1 pedals went back to Chain Reaction for a warranty repair (battery issue, possibly my fault...) and I've now been issued a voucher to buy a replacement set. Which causes a bit of a dilemma...

Favero Assiomas would be my first choice, but they're out of stock at CRC. I have 3 months to use the voucher, so I could wait but CRC told me they don't know if/when they'll get them back in stock.

So that leaves either the Garmin Vector 3 or Powertap P2. The voucher I have is for £490, so I'll have to put some extra money in and currently, the Garmins are £599 in the sale vs £689 for Powertap.

The Powertaps are ugly and heavy (why did they make the P2 silver? It looks even worse...), but I've heard so many horror stories about the reliability of Garmins, it puts me off them. And at least the Powertaps are a known quantity (I think the upgrades from P1 to P2 are pretty minor).

So, do I:

1. Wait and hope the Faveros come back in stock (but if they don't, the price of the Garmins and Powertaps could go up as they're currently discounted)
   
2. Spend the voucher + £100 and get the lighter, better looking Garmins, with the knowledge that they could give me issues.
   
3. Spend the voucher + £200 and get another set of Powertaps
   

I'd hold on for the ones you want - do you really want to end up with pedals you don't like as much just because of stock issues?

If you're worried the voucher will expire, could you buy one of the others and keep under the bed unused until the faveros come back in stock, then return them? Don't CRC do 12m returns?

That is a good point about buying a different set and returning, hadn't thought about that. Makes waiting much less risky.

Another option would be to go for the single-sided Garmin Vectors, which are £340 in the sale, and then have £150 left of my voucher for other toys.

I recently bought Garmins because the Faveros weren't in stock. Price is the same give or take a few quid. Used the Garmin for a month or so inside and out pretty much every day - not a single problem with them. Readings are nigh on the same as the Quarq also. The only issue that I read about concerning the Garmin were the drop off in signal and battery due to the battery doors- they seem to have solved this and credit where it's due, Garmin warranty has always been great with any issues I've had with head units.

anyone with 4iii? i have been given a halfords voucher so thinking to get one of these - fits my budget

I got some Assioma Duo a month or so ago from Wiggle. They were out of stock with no date on but I had the notification on. No wonder they went quickly once they arrived as I got them for £504.

Quarq PMs. I have a SRAM 11 speed chainset with 8-bolt spider interface. I'm looking at getting a Quarq spider. What compatibility issues do I need to be aware of (apart from BCD)? Can I buy a spider even if it's labelled AXS or DUB, as long as it's got an 8-bolt fitting?

I’d be careful, some of the DUB stuff isn’t compatible.
I ordered a SRAM AXS spider to go on my DUB AXS Chainset and guess what, I need the direct mount version.

My vector 3 pedals are reporting a software mismatch. The Garmin advice suggests that when they reconnect they'll sort themselves out but so far they haven't. Any suggestions?

I have a G3 rear wheel in my road bike.I never ride my road bike unless it's on the turbo. Are there endcaps or some conversion I can do to use the same wheel in my disc braked cross bike ? And then I can contemplate selling my road bike.

Unlikely. The G3 Disc is a specific hub and uses a proprietary disc rotor. The only thing I could think of is maybe finding one with dead electronics and using your end cap but you may as well just buy another unit.

Bugger.

I have a G3 rear wheel in my road bike.I never ride my road bike unless it's on the turbo. Are there endcaps or some conversion I can do to use the same wheel in my disc braked cross bike ? And then I can contemplate selling my road bike.

Is the current G3 hub a disc hub? If not, then there's no way of converting the hub to a disc hub, unless you can find a replacement G3 disc hub shell as hippy suggests, which seems unlikely. If it is a G3 disc hub, and you need to switch it from QR to thru axle, this can be done on the G3 disc hubs, but not the older disc hubs. End caps are here.

No is standard road hub, 130 mm, I'd contemplated (after looking at the road bike and thinking how little I ride it now and only use it for turbo) the idea of using the powertap in the cross bike (135 mm) for turbo sessions.

In that case, it's a hard no. It would be possible, but buying a new Powertap disc wheel would be cheaper and easier.

Google is not providing me with the answer to this: I have a stages gen 1 gxp crank arm. I'd like to use it on a hardtail MTB (rock lobster, threaded BB, currently running xt). If I buy a pair of gxp MTB cranks, will it work with them? I cannot think why it wouldn't, but stages do now do a 'road' and 'mtb' version of their gxp PM so perhaps I'm missing something.

perhaps I'm missing something

You're missing that MTB cranks have more Q than road cranks. If you put a road NDS crank on an MTB chainset, you will have asymmetric Q and the NDS crank might hit the chainstay.

SRAM GXP road cranks typically allow for the inside face of the crank at the pedal end to be ~61mm off centre, on MTB cranks it's typically ~72mm

Google is not providing me with the answer

It will provide the answer if you ask the right question. The relevant dimensions are all in the SRAM tech docs, specifically a pair of documents called "Frame fit specifications", one for road and one for MTB