I max w for the sustain, I play aggressive by quickly switching to Wilding Claw and the attack speed item is awesome for Wilding Claw, I never said I build trinity force, I said it is possible, and lastly Maw of Malmortius is an absolutely amazing item to have on Udyr it gives MR and attack damage it also gives i think 2 attack damage for every 1% missing health, which is awesome for this build, but if you want crit chance go for an Atma's Impaler that is also very useful
buy hey that is my opinion take it or leave it, also thank you for the feedback on the build

You say that You are going agressive, but You max w first?
You go 21 in offense top lane and rush attack speed MR item even against AD?
Trinity force "isn't usefull on Udyr"? u wot m8
No tenacity item and not even boots of swiftness? Are you trying to be a kite?
Damage choice Maw of Malmortius? No one buys this item late, since its expensive and bad.
Frenzy in offense with no crit strike items?

Well, thats enough for now
Sorry, but -1

I put not enough mana for the cons for people who don't really know how to play him all that well

Udyr isn't really that mana hungry at all for me, I play him very aggressively and this build works for me, but again thank you the suggestions on the build (btw I said you could build a Frozen Mallet) and also Wit's End helps you get kind of tanky if you run into a fight and attack the hell out of the opposing team getting its stacks up, lastly I don't build Muramana because like I said before Udyr isn't that mana hungry

No offense man,

but this is not how i would play udyr top and its probably not the best way.
Firstly, while trick proves it possible, going phoenix or even putting points into it at all before lvl 16 is generally subpar. Max tiger first unless you're against a super roam-heavy opponent or you now you'll be splitpushing all lategame. Going phoenix top sacrifices tiger stance's far greater burst and lategmae scaling for unnecessary AoE damage and waveclear, which basically turns you into a mana hungry shyvana with slightly more cc. Also for the love of god build something for mana early, because mana makes you tanky (more shields/lifesteal), faster (more bear spam) and do more damage (tiger strike spam). You can also build muramana and frozen heart for ****loads of AD.
I would also advice stronly against Wit's End, while its not a bad item it only works with phoenix, which is as i previously said usually better in the jungle. You should try grabbing a frozen mallet on Udyr. Combined with an early tear and boots it makes you tanky, gives you a lot of damage and makes you nigh impossible to escape from. You can then grab mercs, a frozen heart, a visage, and either a BotrK or a tank item and finish your Muramana for full build. That makes you tanky, do lots of damage and gets rid of your sticking power- and mana problems.
This is coming from someone who has played quite a lot of games as Udyr Top, albeit not in ranked (i hate the atmosphere), and i've played before and after his "rework".

Makes sense I actually haven't thought of using anything Doran's on Udyr I will try it though

doran's shield + pot.

Also I get boots first on Udyr because I like the Movement Speed for his Blazing Stampede that way I can catch most people but what item would you get instead of Boots

I rush Wits's End for its passive because you get 25 Mr when you get it then you deal Magic Damage plus once you get 5 stacks you sap an extra 25 Mr so I think it is pretty awesome. but we all have our own opinions so please tell me what item you would use instead of a Wit's End

would never build boots first on udyr.

Wit's End is a horrible item in general, dont see why you would rush it.