PoorInRichfield

I have a Trek Domane SL7 with Shimano Ultegra 11-speed Di2 group set and a Praxis Shimano T47 Inboard Bottom Bracket according to the Trek web site. I'm considering replacing the crank set with a SRAM/Quarq or ROTOR crankset (or some other non-Shimano crank set) as there seem to be a lot more power meter options available (i.e., crank-based, spider-based, etc.) However, I'm not in-the-know on SRAM bottom bracket standards these days and find the options a bit confusing. I'm also concerned that if I go with a different crankset, will that cause shifting issues?

• Should I look for SRAM cranksets that will allow for using the original Ultegra chain ring to keep shifting crisp (like this Quarq DUB power meter)?
• Do I need to be concerned with the "offset" of the chain rings on the SRAM crankset? I.e., if the SRAM crankset puts the chainrings further to the left or right than the original crankset, I'm assuming that could impact shifting.
• I'm assuming I'd need an "inboard" bottom bracket (vs "outboard) as that's what is on my bike?
• I'm assuming I'd have to choose between DUB or GXP depending on the crankset I chose? DUB seems to be SRAM's latest standard and so I'm assuming I should opt for that.

If you've already done this conversion on your Domane, let me know what parts you used and if you're happy your setup.

WhyFi

Do you have a 2020 Domane? Prior to that, all of them had BB90, which would limit your options.

The easiest, regardless, is going with a crankset with a 24mm spindle. Power2Max has Rotor cranksets with 24mm spindles. That's what I did with my (2018) Domane (and then moved it over to my Cervelo). edit: if you want, they do have them with Shimano 4-hole drilling, so that you can continue to use your Ultegra rings.

For SRAM, you'll need a different BB that'll accommodate the 24mm/22mm GXP.

If you do have a BB90 frame, it's going to keep you from going with a 30mm spindle (though there may be one or two BB options out there that would give you really dinky bearings to fit in the bore). If you do have a T47, swap the BB and giddyup.

Dirty Dude

Are you going to changing power meters all the time? If not, pick the one you want and then change the crankset if needed. Or look into pedal PMs so the crankset doesn't matter.

In my recent experience, Stages' customer service is total crap as are some of their non-power meter products. They have single/double-side options for your Ultegra setup, but I just can't recommend them as a company.

jaxgtr

I just replaced my Praxis T47 BB with a BBInfinite T47 Ceramitec, but I stuck with my existing Ultegra crank. If you want to go DUB, they have DUB based internal bearing option which is what you would need as the Domane's run internal bearing T47's. I have to say, the install was a piece of cake and made a world of difference over the Praxis BB. I

jaxgtr

That is odd, as my couple of experiences with Stages has been nothing but stellar. On my most recent need for customer service in Sept, I sent them an email about my Stages smart bike I bought, as the right side cover had a broken retainer bolt post. They responded same day asked for some pics, which I gave them and they sent me a new cover that same day. Got the cover 3 days later. I had a similar experience on the one other instance where I had to contact. Could have just been a one off bad experience.

Dirty Dude

My power meter came out of the box reporting the wrong crank length. None of their documentation covers how to correct it because I presume it's not meant to be user-accessible. I started a support ticket and it took them three weeks to respond with how to do it. While I had them on the line, I mentioned some persistent battery and dropout problems I'd had with their cadence and speed sensors being used with an L10 Dash. They wanted the L10's serial # and after giving it to them, I was told that 1.) it's out of warranty two months after purchase from an authorized dealer and 2.) that I'd have better results with a more expensive L50 or M50 Dash, but that they'd give me 30% off toward either one. I'd had quite enough at that point and no intention of giving them more money. I've read other accounts of poor customer service from 2019 and 2020 as well, so whether it's the exception or the rule, it is still happening.

guachi

I have no experience with changing from Shimano to SRAM but have you considered power meter pedals? It certainly doesn't take much technical knowledge (I did it, so it can't be that hard) and the pedals can be quickly moved from bike to bike, if you happen to have multiple bikes.

PoorInRichfield

Correct, 2020 with T47 bottom bracket.
My Domane is my "one bike to rule them all (almost)"... I regularly swap between two wheelsets and two pedals sets. When in "gravel mode", I put on my gravel wheel set and Shimano SPD pedals. In "road mode", I put on my road wheels and Shimano SPD-SL pedals. Hence, I think a crank-based power meter is probably a better solution for my needs since that part doesn't get swapped when changing my bike's setup.
Sorry to hear this. I've considered Stages and 4iii as both "good enough" for my power meter needs, which is purely for health and personal fitness tracking and not racing.

In doing a little more research on this, if I want to keep my Ultegra chainrings, my options are limited to just the SRAM / Quarq Dfour DUB power meter spider ($400) and a DUB compatible crank set. If the chainring doesn't really matter much in terms of shifting performance, that'd give me many more options. I've read that Shimano chain rings shift better than SRAM, but I've never owned a SRAM group set before to be able to confirm or refute this claim.

WhyFi

Or a Power2Max Rotor crankset with Shimano 4-hole drilling, without changing the BB.

PoorInRichfield

Thanks... I wasn't aware of the Power2Max brand. Two options for Shimano Ultegra:

• NG Rotor ALDHU R 24mm with cranks ~$1,000
• NGeco Rotor ALDHU R 24mm with cranks ~$700

For my needs, the NGeco would likely be fine. Apparently NGeco is a little less precise than the NG.

WhyFi

I've been running a P2M/Rotor NGeco for 4 years now - nothing but reliable. Yeah, the eco is spec'ed at +/- 2% as opposed to +/-1% - not a biggie, IMO. The other differences are features like (quasi) balance and pedal stroke, which are pay-to-play on the eco (I've never bothered).