I was trying that, but I don’t think that I was using a high enough pressure. Only once I got about 100psi in did the bead “pop”. Trying to do it with a presta-schraeder adapter was a lost cause.
I unfortunately think I am going to have to remove the tire redo the tape and try again.
Heating the tire up ahead of time helps. It softens the rubber and makes them easier to stretch. I usually use a hair dryer, but putting it out in the sun has a similar effect.
This is how I get my tubeless tires on
Good to know I’m not the only one who had issues. I’m using Vitoria G+ road tyres 23mm on my prime wheels, and it took my HOURS to get them on (this is with inner tubes). I was considering my trusted 25mm gp4000sii’s as I’ve not had a problem on other bikes but now I’m not so sure!
Every time that I had an issue with it holding air I have found that it was a rim tape issue. Slightly off, pulled to the side, etc… Especially when it’s a struggle to get the tire on, somehow the tape shifts and causes a leak.
I know that you enjoy coming into threads and telling everyone what they’re doing is wrong, but it seems like you’re completely missing the point here. How many watts/seconds does a flat tire cost you in a race? Unless you’ve got a team car following you around, avoiding punctures will make you faster.
Do it wrong 10 times and then it’ll get better 
THinking about getting a TyreKey, anyone used one and have any feedback?
Pay a professional to do it!!!
Ditto to two other good suggestions above that I forgot but also follow - Warm the tire if it’s cold weather especially, and remove the presta adapter to pop the bead on. From my air tank, I use standard Schrader fitting. With a big volume of 100psi air behind it, it’ll pop on every time and stay. Then add sealant and put valve core in.
Yeah, for sure. You gotta make the call if regular punctures are an issue on the roads you race/ride…exactly as I said in my post. I get the impression from some posters that punctures are a weekly thing. Well then if that’s true you should consider tubeless for sure! Especially if you’re riding in proximity to large patches of tribulus…that stuff sux.
But, as somebody who has bikes set up tubeless and bikes set up tubed, my experience confirms that road tubeless is not worth the effort. Not given the surfaces & situations I ride and race in. That’s just that. If you bring in a thousand Mavic/Enve/Orange Seal/ representatives who say road tubeless is the only way to ride…it will still be a bunch of faffing about for nothing.
Just like if you get a thousand folks to say the Earth is flat, it will still be round.
Except for gravel. Tubeless is probably worth it there if you want to compete at the highest level. 
Just the same I have DKed a couple times tubed with no flats. But not quite top 100. So there you go.
I guess you jinxed it with this post 
Progress today. I am convinced that it is a poor tape job from the factory on the Prime wheels. Looking at the other one, the rim tape has two pre-cut holes much like a non-tubeless rim strip. Thye aren’t well aligned with each other nor the valve hole in the rim. I will have to fix that before the next attempt.
Progress made however, I put another 15-20ml of sealant in and tried to work it towards the valve. It seems to have held most of it’s pressure overnight instead of dead flat in a couple of hours.
I have one. Used it to install GP5000 TL on DT Swiss R470 rims. Did the job.
Fitted GP5000 TL on DT Swiss R470 last week. So far so good. Holding 80 psi ok. Sealed easily without sealant with a track pump. Only issue was a mistake in fitting the valve so that didn’t seal. Pulled the tyre to one side and quickly refitted the valve. They ride nicely. Only 60km done so far but will ride 200km on Saturday.
Pretty certain that was my issue too. Neither of the two supplied rubber gaskets with the valves seem to fit particularly well in the rim channel, not even the conical ones. I will pay more attention to that when I do the other wheel
My Schwalbe pro ones are the best I’ve ever used. Easy to seat, tough, and wonderful to ride on. I’d like to know more of your techniques in mounting and your rim prep, tape job, and how you go about it first before weighing in. All I know is the Pro ones have mounted up very easy to every aluminum and carbon rim I have, from DT Swiss to Enve M50s.
So my valve, which is DT Swiss, had a little rubber gasket which I assumed should go in the rim channel. Having googled, I discovered people were putting this under the ferruled nut rather than inside the rim. Once I did this, the valve sealed.
The o-ring was supplied not up against the base of the valve’s rubber seat, but at the bottom of the external thread - so I think this is the intended arrangement.
Helps evenly apply the tension to the valve stem. Not sure if it actually seals anything. Also stops you from scratching your paint, or worse, crunching a carbon wheel, with the external nut.
Sometimes I find an extra, short strip of tape on the inside at the valve stem gives a little more to seal against than a single layer. Not all valve stems fit well with all rims.