Apart from the fact that the old 50% bonus crit damage suited Garen well better for bursting down squishies, new Infinity Edge only works with additional Crit items now, rendering it completely useless on him. His E being able to crit thus basically aswell.
On a side note: i still haven´t figured out any adc build with new IE that gives u exactly smooth 100% crit chance.
Let's be honest, was anyone really taking IE on Garen on purpose? You wouldn't do it unless extremely fed.
I don't thin riot considered Garen's interaction with crit chance at all with this patch. It makes the E's crit element entirely redundant and nearly unusable. On top of that they are bringing back Atma's and removing the crit chance from it, like what the hell man.
Unfortunately with the current Itemization I think it might be time to remove the critical chance element from his E entirely and simply buff the skills AD scaling to compensate. I am always a fan of stat scaling as it is a easily changeable fix that is quick to fine tune or hot fix in case the changes are underwhelming or overwhelming.
But really the problem with Garen is one fundamental to his kit, the game has drastically changed, and he no longer has the tools to keep up. Without any form of crowd control, a dash, or in combat healing he doesn't have the options that other top laners have and he can no longer keep up with the mobility meta.
Suggestions:
Add a small Rengar/Illaoi leap to the end of Garen's Q that triggers in a certain range. This will allow him engagement opportunities without burning flash, but wouldn't be overly strong because he has no crowd control to back a hard engage and displace the enemy team. It just follow his current doctrine of "run at dudes and jump on them" except with an actual jump. This will also help his laning phase against the increasing prevalence of ranged top laners, giving him opportunities to outplay them.
Add crowd control. Lets face it, with the ever increasing mobility meta the viability of a "tank" with no crowd control and functions as a Pseudo-Assassin until he falls off is pretty nil. While I agree that adding easily accessible crowd control his his kit may prove to be too strong it doesn't hurt to experiment with it. Adding a minor slow to his E that Mirrors the current philosophy of being weaker against a group may be the thing that forces the enemy to want to keep him away and actually waste skills on him when building tank. Knowing that him slowing the entire team in a cluster is a very real threat or having the ability to slow an assassination target without being reliant on Dead Mans would be a good boon to him.
Alternatively on the opposite end of the spectrum some element of crowd control could be added to his ult similar to other demacian melee champions such as Poppy, Galio, J4, or Xin. Something simple that interacts with how his kit functions normally but adds slightly more flavor to it such as "If an enemy is executed by Demacian Justice, enemy champions within X units of the impact site are dragged to the center". This would cause enemies to avoid wanting to cluster around the villain for fear of getting dragged in and actually fear the justice coming their way. This suggestion is especially good because it gates the crowd control element with the pre-requisite of killing an enemy with an ability on a long cooldown.
Allow Courage to stack infinitely while decreasing the rate that is increases past 40 Armor/MR. This will have little impact besides making him Tankier in the late game of allowed to farm past 160 units.
is prefferable on 
with Boneplating for reduced damage. It'll be even better when Spear of Shojin comes out.
Although his E should have a change, because armor break, crit and true damage don't go well. And the only reason his armor break exists is because of 
. But hey.... better all 3 then nothing I guess. :/
Also, why is no one adressing 's bug where his Q proc's 
before the strikes a target? It's annoying.
Garens E definetly needs a change its redunant . Max Q is the way to go E is only usefull if you want to clear waves and even then its badly cooded so you have to buy tiamat or bamis to be more consistent last hitting...
If you can not get 20% crit anymore you will never be able to get a smooth 100% crit chance
play justice garen: 
i shit on most carries with this and because i build more tank items after the deadmans (SG most of the time, even the deadmans isn't core tbh, but preferable) I don't really get bursted either. the new item seems to fit into my build quite nicely too tbh, might try it out, QspinQ.
But if you want a crit build wouldn't going 
// + work? You'd end up with around 60% crit and it would convert a part of your spin to true damage, combined with your ult's true dmg.
Am I the only one happy here that a tank on steroids like garen can't abuse that item anymore?
And no, don't come with the bullshit that he is a juggernaut. They might wanted him to be one but atm he one of the tankiest champions in game (nr 12 at damage taken but if u remove trynda and healers, you get nr 6 with shit ton of damage and 0 fancy mechanic
i still haven´t figured out any adc build with new IE that gives u exactly smooth 100% crit chance.
Good. The new build is supposed to make champions not crit-stack 100% and it's supposed to tone town damage (as well as make crit-bruiser builds worse). Before everything was based on crits and disgusting amounts of damage way too early. Sure you could "technically" get 120% crit chance but then you'll miss out on damage because the only way to get crit chance is to get attack speed.
Meta has shifted away from crit champions now, which is interesting, but it's nice, because instead of melting you with 2 autos, they can melt you with 3.
Just build a different crit item first?
They should reduce crit items from 30% crit to 25%, no idea why they didn't.
Best crit build for garen is like 
Boom you explode any carry ! Joke aside, now that IE interaction is gone with Garen E, maybe they could remove it and add power somewhere else or increase the damage from E or literally remove the level interaction with his E. Garen could be better and tbh the crit damage was nothing but a useless gimmick.
Try IE into phantom into shiv. U might be surprised how well you can do.
