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I have a fatbike that weighs 28
with 3.8 in tires
1x11 drive train
10x42

Bike 2
weighs 36
4.5 in tires
1x12 drive train
11x50 cassette
Question is bike 2 a better bike for hill climbing
wil it handle better in hard pack dirt cornering, flat ground
both bikes have a shock fork
i ride mostly hard pack trails with roots and small stumps
i an trying to figure if the specs on bike 2 will help even though it’s heavier

I_like_e_bike

which brand did you buy？

prj71

No. You have 8 more pounds of weight to pedal uphill and the wider tires (more friction) are working against you.

Yes...cuz wider tires have better traction.

KPREN

Which bike is better is strongly dependent on what you want to climb and what tire pressures you are running. Bike 2 is better for climbing sand, snow or mushy terrain. Tire pressures make a big difference on these types of terrain. If you want to climb hard pack or pavement then bike one is the better choice. Play around with tire pressures on both bikes when riding in rooty terrain. Either one may be better or worse.
When it comes to traction for cornering, tire pressures once again may change the way you view each bike. Conditions such as loose round gravel may offer much poorer traction on a fat bike with too much air in the tires. Like being on marbles where a skinny tire will not have this problem. Running too much air in fat tires gives fat bikes a bad rap.

Most fat bike riders have too much air in their tires. With 4.5" tires I might run as high as 16-18 psi air pressure in the rear tire on pavement and as little as 3-4 psi on snow Hard pack with roots I would be running about 8-11 PSI
Remember, perception is reality. Whatever bike feels better is the better bike even if the numbers don't say so.