I purchased an SL7 and I put a 53/39 on it due to the advice of a guy at my LBS. After riding a couple of times I’m nowhere near strong enough to push that gear ratio and I’m looking to move down to a 52/36. They are praxis chainrings and I’m wanting to know if I will run into compatibility issues with my quarq Spider since I’m going from 130 BCD to 110 BCD?

110mm BCD rings will not mount on a 130mm BCD arm, so at a minimum you will need a different crank. Depending on which specific crank you use, you may also need a different bottom bracket.

Sounds expensive and yes I’d have to replace the quarq PM also. Could I put a 12/28 or 12/30 cassette to ease the ratios a bit? I currently have an 11/28 with that 53/39.

In principle, yes. The wider gear range will likely require a longer chain, and perhaps a different derailleur to properly handle the additional chain length.

A 12-28 shouldn't require any change.
A 12-30 means you'd need (on paper) another 1/2" of chain for the 2 additional teeth of the largest cog.
Do the test in the pic below- Chain on largest ring & cog.
IF you have at least 3 half links slack, you won't need a longer chain for a 30T cog.
Without knowing what RDER you have, one doesn't know how much chain wrap capacity OR the largest cog it could handle. You "might" be ok with a 30T?
You "might" have a bit of chain sag in small:small.

53F 30R might be a bit short on links. Which shouldn't matter as Big Big causes frogs to fall from the sky. If it were me, I'd risk it & try the 12-30 with 39t - 53t

id just get a larger cassette first , or then a custom gear ratio,
really you are not going to get an easier ride , you are just going to loose efficiency and feel like its easier by sizing down , but you will just be wearing your parts out ,
try to match your gears to your cadence and keep the chain line strait as possible by adjusting your cassette ,
for example i ran a 55 tooth chain ring and it actually made my ride easier on the flats because my chain was strait on , and the larger the gear size the more efficient your drive train , but the down side was i was running a 11/28 so i lost any climbing ability , but i could have just got a 11/36 , it was also 1x so i didn't have an lower chain ring , but it was definitely smoother and changed my ride a ton ,
if you are prepared to invest in your drive train try to get that most commonly used gear that maximizes your cadence efficiency in the straightest position on the chain , that doesn't always mean just size down , although it might just be a cheaper option and if you dont care you will just get used to it , but thats a psychological effect , good luck

There's no point in spending a bunch of money to go from 53/39 to 52/36. You get about the same low gear using an 11/30 cassette with maybe no other changes.
On the high side you are 3 or 4 gears above Eddy Merckx in any case, and you are not him.

Contrary to JohnDThompson the crank and bottom bracket could stay and replace only the spider/PM.

I suggest leaving the front and using an 11/36 cassette, with a long cage RD that will run it. That and a longer chain will get about 28 gear inches, down from the 36 G.I. that you have now.

That , or HTFU, I guess, but when I was in that situation, I changed to 48/34 withe the smaller spider, later adding the spider PM. Ran that with 11/28 for quite a while, but now have devolved to an 11/34, for a 1:1 (26GI) low gear.

Change the cassette and live with the gears you can't push. There are aftermarket cassettes that start with a 12t or sometimes even a 13t or 14t, brands like Miche. I'd live with the slightly heavier cassette and run wider gears and a new chain over swapping a crank. Might always need the old chain and cassette on something else at a later date.

Another option is to get the proper crank you want in a 50/34 combo as just going to a 52/36 isn't much different than what you have. Sell the barely used crank you have to recoup some of your losses. Seems to me like the cheapest option plus you'll have the gearing you want although I don't know too many people who can use an 11t cog even with a 50t chainring but you can change that when the cassette wears out. I'm a little curious about why the shop recommended the 53/39 combo unless you convinced them you were a pro racer.

They must have been impressed by my calf muscles 😆

Are you certain about this? I ordered a 12-28 to see if that helps. If that doesn’t help me the worse case scenario is just selling the PM & standard chainring and then go to a 52.

Ha ha, When they see me they recommend I stick with an exercycle.

Actually, that is only true with SRAM or S works cranks with replaceable spider. Not true with Shimano- my bad.

Changing from 53 to 52 chainring would reduce speed at 100 rpm from 37.8 to 37.1 mph. That is likely not the reason for changing gearing. Most folks go to 34/50.

Play with this:

https://mike-sherman.github.io/shift/

They are sram red cranks.

A 12-28 cassette gives you the exact same lowest gear as an 11-28

Do you only have one gear on the back of that bike? Unless all your riding is on the upside of a hill with 8% grade, I'm having trouble understanding why say it's too much for you.

You don't normally ride in the smallest rear cog. Nor do you normally ride in the biggest rear cog. When in either the small front or large front, you really want most of your riding to be in the middle cogs of the rear cassette.

At least that's my opinion and I'm sticking to it.

True but I don’t use that gear anyway, but what the 12-28 does do is add a 21 and moves the 19 & everything else further down the cassette. It also removes the 11 which is another gear I don’t use.