I’m looking at buying a wheel with Powertap hub, but I’m not sure what to go for.

Perhaps the ‘safe’ (but boring) option is the standard Powertap rear wheel with G3 hub and alloy rim (around £630 from Wiggle).

Another option would be to buy the hub with a different rim, and have Harry Rowland build it. I was thinking of a HED Belgium Plus rim (25mm wide). I’ve not tried wide rims, but they might be worth a go.

There’s the GS hub option with straight spokes and DT Swiss internals, but I’ve read some negative comments about straight spokes.

It looks like there are a few second-hand wheels knocking around – I’ve seen the basic Powertap wheel for around £350. Or,there are older hubs – I saw an SL+ (I think) in aero rim and with wheel covers, but that was more expensive. I’ve seen some built with sprint rims, which I’ve used before, and I’m not adverse to, but I had decided to give clinchers a go for now.

It’s for a fairly aerodynamic recumbent, and I’d be using it for general training, on the turbo trainer, and for pacing myself on audaxes etc.

I’d be interested to hear about old vs new hubs, G3 vs GS, and Powertap-built wheels vs hand-built wheels.

PowerTap hubs do seem to have taken a bit of a beating on the forums of late. The old ones were deemed pretty bomb proof (other than bearings) but there seems to have been a slip in reliability with the newer style hubs.

I did buy a new G3 a while back but sent it back as i couldn’t get it to consistently pair with any head unit. Meanwhile my old Pro has been doing sterling service on the turbo bike for a few years now without missing a beat. But that’s just my experience, sample of one etc.

Recommend having a trawl of the forums and seeing what issues come up.

Out of interest, why the PowerTap and not maybe a crank based or pedal based PM? If my old PowerTap ever died I don’t think I’d replace it with another wheel based system (I’ve also got a Power2Max and a Vector PM.) TBH now that they have the pedal and spider based PM’s I would be surprised to see PowerTap drop the hub in a few years time. I guess sales will dictate.

Thanks very much. I wasn’t aware of many problems with the new hubs. It might be worth looking for an older hub/wheel which has been looked after and serviced.

I had originally thought I’d go for a pedal-based powermeter – mainly because it would be usable on my weirder bikes (which have different wheel sizes and cranks). However, the Powertap has a couple of advantages – apparently it works with oval chainrings (I have Rotor QXL rings), plus it’s downstream of any drive-train losses (apparently better for measuring CdA, which is another thing I want to use it for). Also, they’re still cheaper than a Vector or P1.

There are a few non-hub based PMs that claim to work fine with oval rings, the P1 being one of them. I think it’s something to do with how often it measures angular velocity. The Power2Max claims to do it too but I don’t think they’ve said how, but readings with Rotor Q rings from mine are consistent with the PowerTap so I’m inclined to believe them.

For measuring CdA, does it really matter as long as it’s consistent? I’d assume you’re doing it to improve your CdA rather than just to generate some number.

I hadn’t realised the P1 would work with oval chainrings.

I don’t know a lot about measuring CdA and Crr. A couple of people who do mentioned that they like Powertap hubs for that application. The aim would be to see if changes to the bike and riding position showed any improvement. Also, it would be nice to be able to compare my measurements with known figures for other bikes.

PowerTaps (at least older ones) do seem popular for that purpose. Mostly I think because of accuracy and reliability. Did a session the other week at a velodrome with Aerocoach and they fit a PowerTap on all client bikes for testing purposes.

CdA, if you’re just doing field tests maybe using something like Aerolab then it probably doesn’t hugely matter as you’ll probably have a fairly large percentage of error on your measurements, which makes comparison tricky.

G3s are utter toss – the old SLs etc. were, as stated above, pretty bombproof, but they started going downhill when they went from 12 to 15mm axles. The G3s take this a step further and reliability has dropped off a cliff.
I was a PT user for nearly a decade and loved them to bits, now a very happy Power2Max user instead…

Returned my powertap twice in a year, just sold it and moving into something else

My old PowerTap Pro was fantastic for years. Then it broke. Replaced with a G3 at a subsidised cost and sold to Kryton of this parish.

Just to be the opposite. My old elite+ was nothing but trouble. I think though it was the sealing that was pants.
Since getting its fourth torque tube it has been on the turbo.
My G3 got the updated endcap and since then has been really good- I test the slope quite often and it always seems bang on.

The service I got from Paligap was great too.

Aero testing sucks – we hardly ever have days where the air is still enough. Some guys who are super slippery seem to aerolab all their rides and can spot trends, this might be worth trying, I can never be arsed. I managed to get pretty aero by changing something, racing a familiar course and looking at my results within the field against my average power. Huge potential errors but it worked for me, maybe more luck than judgement.

I hate them. The experience I have had has left on edge every timei use it: bought in 6yrs ago, bearings went in 2 month (turbo use only) and nine (I kid you not) torque tubes. Yes the service has been good, I have only paid for one torque tube but at £450 that was one to many and also explains by nervousness. In the future I’m buying a pedal based system for the ease of swapping between bikes. On the flip side, one of my buddies has a centuries old pt and he’s never had a problem .

Aero testing sucks

It does seem hard to do with any degree of accuracy. I’ve been reading loads of stuff on Aerolab and mostly the consensus seems to be that it can spot trends but back to back testing of marginal stuff is hard.

Can recommend an Aerocoach session (had my first one last week.) Got to do about a dozen runs round an indoor velodrome trying different things out. You get instant feedback on the impact of that change after a run and I’m confident in the outcome. Was good for me as I don’t have the spare time needed to mess about with field testing and Aerolab. And it’s a lot cheaper than tunnel time as well. Knocked just over .01 off my CdA in the session, but also got loads of good advice about what direction to go in with future changes.

Can recommend an Aerocoach session

Thanks, good to know. Funnily enough I booked in with them today. It will be interesting to see if it matches up with the tunnel. I am planning to pre-ride an aggressive position to see if there is any power loss and then see if the trade off is worth it.

I hope you see good returns. A friend has seen some great results already. I am realistic, there comes a point when any returns are going to be marginal.

Hmmm… There are quite a lot reports of failures. A new one would have a warranty, but may not be as reliable as an older model, although a quick web search shows a fair number of problems with all generations.

I think the uncertainty would be worrying. Also, it would be a real hassle having to post a complete wheel just to have a power meter serviced or repaired.

I might still be tempted, but I think I’ll have to consider alternatives.