As i say if you alow your self to get one wave of minions advantage you will have enought time to get to tower before it actualy come in danger. Also using charge while you are still next to shop will instanty regen mana to full and you will be there in no time problem come if you are vs nasus (or someone else who can kill tower in few swings) and powerfull aoe champion as minions will go down to fast then. Ofc you can just call jungler to replace you on 15 sec every here and again.

If you take 15 sec to get to a tower and there is a decent ad champion there that tower is gonna go down faster than a korean missile.

I'd rather have phage before sheen, in my opinion. It's very useful for ganking with its passive slow. I can understand taking sheen before zeal, but I love speed above the bonus damage.

Also for your farming stand at turret and count hits. Melee minions die from your single autoatack after 2 turret hits and ranged from Rampage + autoatack after 1 hit. You wont be able to colect all 6 minions kill, but 4 or 5 last hits on 1 group is realy easy job.

As Hecarim you gain nice amount of ad from speed but boots of swiftness are not way to go you need either Mercury's Treads or Ionian Boots of Lucidity, Sheen must be build after you have Boots of Speed (optional you can first build better boots as mobility is way you will survive in line) again Sheen is most important item for your early and mid game and will do around 20-30% of your total damage. Flash is maybe between 3 worst spells for Hecarim. If you turn in Devastating Charge no one can escape you with Devastating Charge + Ghost combo you can get cross line harass in apx 2 sec (750 + speed) or chase Master Yi / Rammus. Teleport is not that bad but you can get from base to turret in 15 sec just make sure there are no minions in front of your turret and that they have to kill one wave before you get back and you can skip teleport and take heal/ignite/exhaust I can see you made tanky build but you didn't say anything about gameplay.

The guide is quite brief and I miss a little detail about the champion as new players won't get much out of this.

Also I still believe Hecarim is quite mediocre if he and the team make no use of his Q ... in lane I find him underwhelming and in jungle just about average. There is no reason why I would choose him over some other champs who fill his role better atm...

I like the build and its not the best AD or the best tank but it is the good in most aspects.

This guide is a strong one, even though his passive maay not give him the best of AD bonuses, it makes him a great tank dps bruiser, and the movement speed makes him a great initiator

Do the runes even need explanation? Its pretty basic runes for a off tank.
And im not finished with the guide yet, I just put it up for people to use, thats why it seems incomplete.
Oh the reason i dont get dorans shield is because I'd rather get an item i can build on at the start, these are pretty expensive items and the 10g/5 sec is great to get enough money for everything.
I'll think about changing shurelya's, but what item should I replace it with? Sunfire cape for the health and plus the passive on it? Hes gonna be in the enemies faces so i think it would be good.

Firstly, I don't like using movement speed quints, boots of swiftness. Why stacking so big movement speed? Your passive doesn't give so much AD.

Secondly, why do you build sheen as 3rd part of Trintiy Force? In my opinion too late, again focusing on movement speed.

And lets continue. Regrowth pendant... Well, against heavy harass. But i would rather take Doran's Shield, Hecarim has low base armor and he needs to compensate it somehow. And Shurelya's Reverie... That item is good, but should be carryed by support, not by you. Waste of item slot, take something else. Also, you didn't explain here how to play Hecarim and so on... Nothing about gameplay itself. Just explanation of summoner spells (flash is for squishies and champs like alistar or rammus who need it, but not for most of other tanks). No explanation for runes and only 2 other situational items.

The whole guide is unfinished. Build isn't bad at all but there isn't written almost anything what should be in every guide included.