Power meter advice

[E65Ross]

Bit annoyed with power2max, I've just ordered (and had delivered) a Canyon Aeroad with the latest Ultegra R8070 groupset. I sent them a link to the bike and they pointed me in the direction of the power meter I needed, which I duly ordered.

I get the unit, and bike fitter says they've sent 5-bolt rings, rather than 4. I contact power2max and say they've sent the wrong ones and now they're saying they don't make 4 bolt set ups at the moment Quite why they sent me a link to one then, I've no idea.

Any suggestions for a crank-based power meter which would fit? BB type is PF30 I believe.

Thanks

edit - this is the power meter I got

https://www.power2max.de/europe/en/Produkt/favorit...

It says "110 4S" for BCD which is correct....so maybe I just need some suitable rings? If so, any suggestions? I'm after 50/34.

Thanks

Edited by E65Ross on Thursday 4th January 14:14

[Teebs]

I've got Praxis Works Buzz rings on a Quarq Dzero and they've been fine.

[E65Ross]

Ah,

having spoken to power2max and my bike fitter, it appears the original Ultegra chainrings WILL fit the rotor cranks, so that's all good.

They are 52/36 and I want 50/34 so I will change them at some point very soon, although I'll still be able to ride with the power meter for the time being.

Any advice on some decent 4 bolt 50/34 rings?

Thanks

[upsidedownmark]

Slightly bemused.

If I read it right, you have a 4 bolt spider from power2max.

For some strange reason you've been sent some 5 bolt rings, which are no use to you..

You have an ultegra chainset with 4 bolt rings. Just bolt em to the p2max and you're good to go - there's no reason to order rings at all really.

If you want other 4 bolt rings, any shimano ones would do. I guess there are other makers, but seems the main reason to go 4 bolt would be to be able to use shimano rings which are as common as muck..

ETA - oops, beaten to it!

[E65Ross]

The main reason for ordering the other rings was to go for 50/34 rather than 52/36. I've never tried semi compact so may just see how I get on. I have some steep (pushing 20%) climbs near me which is why I opt for a 34T inner ring and a 30T cassette....But on the whole it's pretty rare for me to use 1st gear, just up longer climbs. I have a few long climbs near me (I have a few 1-2km climbs at 6-10% when I can do 2nd gear no problem (27T) but I prefer a slightly higher cadence.

I've also gone for shorter cranks which may increase cadence.

We'll see how I get on.

[z4RRSchris]

i have 2 stages units (sram and shimano) and a quarkDzero unit.

They measure pretty much the same, the stages are obviously very easy to transfer between bikes.

Both stages have failed once but were replaced very easily.

[E65Ross]

Thanks. It sounds as if I will be able to use the power2max unit now, just with Shimano chain rings. I just need to find 50/34 4 bolt rings now. Tempted to ride the 52/36 and see how it feels.

[okgo]

I would imagine it will feel no different, because you know, gears are gears, and you can select the one you want using the 11 at the back

[nammynake]

Lowest gear of 36-30 is similar to 34-28 (marginally easier in fact) - low enough for occasional 20% gradients. Unless you think you need 34-30? I would only use that if regularly riding 20%+ hills.

[E65Ross]

okgo said:

I would imagine it will feel no different, because you know, gears are gears, and you can select the one you want using the 11 at the back

Yes, but 34-30 isn't the same as 36-30

I think I should be alright to be honest, I think I'll use them and see how I get on.

Utterly insane that power2max shipped the 5 bolt chain rings in the same bloody box as the 4 bolt power meter and cranks!! They've offered a refund but I'm going to ask if I can get them to pay for postage. I don't see why I should have to pay return postage when they've sent the wrong items. When I ordered the power meter I chose the correct BCD and chose a 4 bolt system, below that I could choose the rings, and there was nothing to say they'd be 4 or 5 bolt, so I assumed they'd fit.

Anyway, I think all should be well and I will be going to get the bike at 1pm tomorrow.

[BeirutTaxi]

z4RRSchris said:

i have 2 stages units (sram and shimano) and a quarkDzero unit.

They measure pretty much the same, the stages are obviously very easy to transfer between bikes.

Both stages have failed once but were replaced very easily.

I'm surprised that they are the same. My L/R balance changes as I get more tired towards the end of a long TT which would obviously be an error with left hand only. I use a P2M Type S and it wasn't that much more expensive than left hand only options.

[russy01]

You’re a whippet, you’ll fly up those climbs on the 52/36

[E65Ross]

After some emails to and fro, power2max were originally offering a refund but NOT a refund on the postage. I said I didn't think this was fair because I clearly ordered a 4 bolt spider and, in their dropdown menu, there's nothing saying that the rings I was ordering was a 5 bolt set up. I just chose 110BCD which is correct. If they don't offer 4 bolt rings with a 4 bolt spider, surely once you select a 4 bolt spider then you shouldn't be allowed to choose rings, or at least be given a warning!?

After several emails they actually phoned me up from Germany and have agreed to pay the return postage cost for me. Only about £7-8 but don't see why I should pay it.

I'll stick with the 52/36 for now and see how I go.

About to jump on the turbo trainer in a bit and then after an early lunch I'll be heading to the bike fitters to collect it He said it's all set up now with the original rings but using the rotor cranks and power meter

[idiotgap]

To save a fiver against the price of a 34/50 I ordered a £32.50 105 chainset in 39/52 from Merlin a few weeks ago. I'd only ever had compact before. I made a little spreadsheet and ran the numbers and worked that with my cassette (an 11-32 hg500) I was only losing the very bottom gear and I've barely noticed the difference. I'm sure you'll be fine.

[Matt_N]

Where are you riding that you need a 34-30, you're a strong rider, you shouldn't really need that kind of ratio?

[E65Ross]

Matt_N said:

Where are you riding that you need a 34-30, you're a strong rider, you shouldn't really need that kind of ratio?

It's not really a case of needing it, it's just being more comfortable with it. I ride a lot around the South Downs, where there are some pretty steep hills. I rarely use 1st gear to be honest, but there are a few I like to.....one in particular is around 18% and at my FTP (currently 235W) and weight (55kgs) I can't get up it without going well over 100% FTP and doing around 70rpm! I typically like 95rpm, but to do that up this hill I'm doing around 160% FTP....not always ideal if you don't fancy caning it!

[RGambo]

E65Ross said:

okgo said:

I would imagine it will feel no different, because you know, gears are gears, and you can select the one you want using the 11 at the back

Yes, but 34-30 isn't the same as 36-30

I think I should be alright to be honest, I think I'll use them and see how I get on.

Utterly insane that power2max shipped the 5 bolt chain rings in the same bloody box as the 4 bolt power meter and cranks!! They've offered a refund but I'm going to ask if I can get them to pay for postage. I don't see why I should have to pay return postage when they've sent the wrong items. When I ordered the power meter I chose the correct BCD and chose a 4 bolt system, below that I could choose the rings, and there was nothing to say they'd be 4 or 5 bolt, so I assumed they'd fit.

Anyway, I think all should be well and I will be going to get the bike at 1pm tomorrow.

a 34/28 is a 32.8inch gear a 36/30 is a 32.4inch gear, so it is infact easier to pedal a 36/30 than a 34/28.

[E65Ross]

I was running a 30 tooth cassette beforehand.

[ALawson]

I used to run 50/34 with a 11-30 on my Roubaix, Tarmac is 52/36 uk is mainly 11-28 unless in Shropshire or other steepstuff then long cage (or not a short one), allows 11-32.

It was fine for the Marmotte and Tiede where you are going up hill for hours 36 : 32 if needed.

FTP 280ish, pie weight of 80kg.

[RGambo]

E65Ross said:

I was running a 30 tooth cassette beforehand.

ahh! missed that sorry.