Enduro bikes for 5'5" rider

I’m maybe an inch taller, so still short! Currently on a new generation Fuel mx. The amount of potential configurations can be a rabbit hole, but it has allowed me to get it set up exactly how I want it to suit my build. 
My son has the sight, but in a s3. Even being probably a size too big, I’ve found it really easy to get comfortable on. It feels like a lot of bike on flatter terrain but really balanced pointed down.

Transition Patrol?

Currently on sale likely due to rumours of a complete revamp next year. I'm taller and on a large but I think it's great.

My 5'5 son is also on a new generation fuel mx and loving it. The prices are also very competitive compared to other options.

Medium Rallon with 450 chain stays. 5’5” isn’t so short that you are limited in anyway on bike choices. 

Agreed - I'm 5'4 and haven't had any trouble with fit. Small SB160 currently. 

Bikes that I have owned that were particularly low standover if that's a concern were the OG Sentinel and the V1 Forbidden's. Haven't looked at them in a while but I know Transitions are still really low slung. 

I'm 5'8" and solidly a medium on most brands.  I avoid Pivot myself because their medium is usually huge, and their small small, so maybe their small would be goldilocks size for you.  I personally really like the Santa Cruzes I've owned, but one issue I'm having with them is their shock tunnel prevents me from running a 200mm in a medium, fully slammed.  You might be able to get away with a 180 on a small, not sure.  I looked at the new Yeti LT but while they figured out the straight/deep seat tube, they made it 420mm long instead of ~400, so again I can't run 200mm.  I know Ibis and Orbea also prioritize good seat tube insertion for small sizes.

Hey,

I'm your exact same size! The cheapest route could be to turn that Sentinel into a mullet with the flip chip in High, up the front travel to 170mm and the shock stroke to 65mm so you can get 160mm of travel in the rear. If the reach is too short, try and get a Works Components +5mm reach adjust head-set and you got yourself a ripper already!

If you want something that fits well I've found that my ideal reach for SM size bikes is 440mm and there's unfortunately very few that have those numbers. The latest Evil Wreckoning hast that reach and is one of the most comfortable bikes I've ridden although it's dual 29". I do prefer longer chainstays now, and since you want an MX setup maybe the new Yeti LT is the ticket. Check that geo out

Forbidden Druid or Dreadnought could work - both have very low standover.

Check out the Jank chainstay extender link 

As a 5’6” rider I look for a few things in a bike.

• Ability for 170 dropper - seems my sweet spot. I use the Oneup online calculator to see what’s possible. 
• 30t chain capability - I do this because I now run 155 cranks and it’s comparable to 165 32. I also run an oval and so it’s really 28t clearance. Many new bikes don’t have that (including hd, stumpy, fuel) due to chainstay clearance. I could prob deal with 165 but I prefer 155 from back to back testing, less knee pain, more free bike movement.  You also can usually get 10mm more dropper. 
• 27” rear wheel - too much buzz w 29”
• For longer travel 430-450 reach seems good and 425-435 chainstay. 
  
  I just purchased the small revel ritual and it ticks all the boxes. I have a 180mm dropper slammed, 30t oval with my stubby 155 cranks. Also the 5010 fits this (170).