The weather here in Arizona is wonderful during the day but cold in the morning and I can’t find a good solution for where to put a jacket and gloves if I start early. I’ve tried a few things but my jacket is too big for my jersey pockets and even a frame bag I’ve tried.
Thanks!!
Arm warmers, wind breaker vest (not jacket). Leg warmers if you really need it. You should be able to easily roll arm warmers and a vest to fit into a standard cycling jersey back pocket.
Where I live, the answer is more thin layers instead of big layers. For example, instead of a big jacket, I’ll wear a base, a SS or LS jersey, and a wind vest. Kind of depends on the weather where you are though.
If you need a wind jacket, get the Patagonia Houdini. Not cycling specific but it’ll break the wind like no other and packs down to the size of a tube.
Get one of those large burrito bar bags to add to your setup for the cool morning training days.
Not necessarily the solution you’re looking for, but if my jersey pockets are full, I’ve been known to tuck a jacket or vest under the top part of my jersey, below the neck. Looks silly but works fine … only issue on hot days is that you’ll sweat through the jacket, so if you need it for a later descent, you can count on it being wet.
Do the pro thing and stuff in under you jersey - lower back where the pockets are
I just use sensible options like the ortleib waterproof ‘saddle bag’ range - small for a rain jacket etc and the large for a full puffy jacket and more 
I have tied things around my bars and stem. May not be aero but it works for me. Doubles as a Garmin warmer.
I have one but not big enough for my XL winter jacket
What part of the state? This morning, vest and warmers and gloves. All fit in the pockets by 11 a.m.
I just ordered a bag like this, I think that will be perfect for what I’m trying to do
I got the sportful hotpack, looking at the pic the material seems to be the same but the hotpack is cycling specific though the hotpack is not the most aero jacket. I often bring my hotpack with me on daytrips because it is so small and packs so easily but maybe I should get the Houdini too for that
I once got one of those bags (the largest variant) thinking it would be an upgrade from my topeak backloader (also largest) but within a few rides the ortlieb sagged onto my rear wheel. I nearly crashed and the bag was destroyed. Apparently you need a specific strap to hold up the ortlieb, which is sold separately… The topeak comes with a waterproof innerbag, which is very convenient to get out stuff…
Doesn’t matter outside racing. Either you’re training to a target or you are just out enjoying a ride. In these situations minor differences in your average speed due to aero differences are not important.
These are great. If i’m on the road bike without frame/bar bag, I’ll voile strap this to the top tube for cafe stops.
Though it sounds like Arizona has bigger temp swings than here (England).
I own and love a Houdini. I take it with me when traveling because it packs small and light. I don’t like wearing a hoodie while riding though, so if I was going to use one on the bike, I would opt for the no hood version. Patagonia Men's Houdini® Stash 1/2-Zip Windbreaker Pullover
The best bang for the buck are arm and leg warmers. You can put arm warmers underneath a long-sleeved jersey, too. In addition, you could take a gilet or a vest. Arm warmers are super useful even on e. g. flights or so. You haven’t mentioned cold feet, but merino wool socks helped me a bunch to stay comfortable.
Overall, in my experience, the best solution is the one that is slightly too cold in the beginning.
I just don’t like the feeling of drag but the hotpack probably is a lot more are and better suited for cycling than the houdini
You’re talking about something else I think - I mentioned/recommended the ‘saddle bag’ range which uses one QR bracket for all of them. Small one big enough for just a tube and tools, to the biggest which is 4.1L.
I think you’re talking about the ‘seat pack’
I had the Topeak bikepacking bag with the inner BTW, it wasn’t waterproof and all my sleep kit/clothes were soaked after a day of rain…
I do also have the largest Ortlieb seat pack and have never had any problem with it, certainly never needed another strap 