Is laptop safe in pannier bag during the commute? Specifically, if I am involved in a fall or crash is my laptop going to be damaged for sure if I put it inside a pannier? I have an expensive work laptop that I need to carry with me and I feel like it's very easy to damage inside a pannier since it's exposed on the side of the bike.
Start by checking with your employer about your personal liability if the device is damaged while in your possession. Mine tried to make a former coworker claim on his home insurance when his work-issued device was damaged.
As for panniers - it totally depends how the laptop is wrapped, the design of the pannier, and how the accident goes down.
Few laptops come with bags these days, so make sure you have something around the whole thing. A close-fitting neoprene slip bag works well, that should take out the high frequency vibrations and eliminate scratching. That goes in your pannier bag, and ideally doesn't flap around. You want to take up slack space with a cinch strap or similar.
I often ride with a work laptop, which always travels in a lightweight hard-sided box made from coroplast, hotglue and tape, and lined with soft cotton. That's not waterproof, so the whole thing goes in a plastic bag which is replaced every half-year.
Final size is 38x28x3.5 cm for a laptop that is 36x25x2 cm.
This box goes into a backpack for a road bike, or for my recumbent I have a "hanging bag" on the left side.
In March 2022 I was struck by a car from the left-rear which impacted the laptop area directly, though I suspect most of the force went through the seat. I broke ribs and was concussed, ended up spending days in hospital.
The damn laptop was fine, not a scratch on it.
Ultimagely, if your employer requires to you cart it around, they can own the risk. It should be zero-difference if the laptop was in a car accident, or stolen from a parked car. Otherwise leave the computer at work.
I commute by bike to work for 6+ years. I have always been taking my work laptop with me in the pannier, together with lunch box, a can of spray deodorant, my work attire (I commute in jumpsuit and change clothes when arriving/leaving).
I have had some occasions where the bike fell down, either because the kickstand didn't do its job or because of a collision with another bike.
The laptop was never damaged. The worst that has happened was the can leaking, ironically when it was at home with the empty pannier.
The only damages the laptop is taking is some wear from friction against the pannier inner bolts, but this is not affecting its operation.
If your pannier is hosting only the laptop, you can consider put some towel/spare garment inside it: it will act as a buffer for the laptop and you never know when you might need an emergency change.
Others have noted that it depends on the laptop, pannier, and specifics of the accident, but I'll also note that how safe it is depends on where and how you bike. It sounds like you regularly commute by bike - if you have a short ride on an isolated bike path that's usually in good weather and have never suffered a crash or collision so far, the laptop would almost certainly have been fine no matter how you carried it. On the other hand, if you bike through a hectic urban area and have been involved in crashes yourself, you should worry more about how the laptop is packed.
The overall probability of the laptop surviving your trip is a function of two probabilities - not only the chance it survives a crash, but also the chance it is involved in a crash in the first place. The first may be more easily controlled by how you pack the laptop, but don't neglect that you can affect the second by choice of route and your own cycling behaviors.
First, make sure you have some comfy lining for the laptop. Your employer may have requirements guidelines for that (we still laugh about 'XYZ approved bag', but its there, in equipment confirmation papers). A good quality laptop bag or backpack suffices. You can get a backpack with removable laptop bag section, so you can use the pack for trips, or bring laptop in another bag using the cushion bag (like your bike side bag). You don't need super cushioning - modern laptops have ssd which are not susceptible to vibrations - the only damage you have to worry is cracking the screen and scratching the chassis above normal wear. Oh, and water.
Note that airlines don't like 'laptop backpacks' as 'free carry on computer'.
Second, make sure what rules for carrying equipment off site there are. Your employer will have a regulations about this. Check them to see if they take responsibility/have insurance for accidents during commute. I assume the laptop will have (hardware) encrypted disk (if not, gently point it employer), and there will be rules for not working on a bus or where someone could watch over your shoulder. It is good to have a kensington wire with you, in case you ever need to sit in public and don't want to hold the bag handle all the time. Never leave the laptop unattended, but if you must, wire it to something big and heavy. Won't stop LPL or someone with basic wire cutters, but stops random person from running off with the bag. Bonus points if you hide the wire, so they faceplant when it yanks them back.
Thirdly, the physical safety at last.
Note that the bike side bags are conveniently in the height range of car bumpers. If you get hit from the side, it will be dangerous for the laptop. Bicycle falling over isn't an issue if you have minimal cushioning.
A safer place for the laptop will be a backpack.
If you commute through crowded areas, consider someone may notice a 'laptop bag' backpack and try to steal from behind you in the crowd. Same with the bike side bag at rear. You can use kensington wire or small padlock on the zipper to spoil that. The ultimate safest place for the laptop when commuting is in the backpack worn in front of you. This is the area you can monitor at all times, in your arms reach, and instinctively protected along with your head shall you fall or get hit.
Laptops differ by how much punishment they can take. [Acer Enduro] that I bought inspired by that YouTube video works on the pannier rack years with no complains. If there is a choice, look for something at least "business ruggedized". This can make a difference and such models are not significantly more expensive (even if some tank-like Toughbooks are).
It think it would make no harm to discuss this if it is a company laptop they are about to buy for you. Some companies have very strict rules on what do they buy but others not.
Speaking about the possible accident, what if it will be no cyclist remaining to operate the laptop? It is better to ride carefully and make the crash unlikely.
Finally, plan your work. Do you really need a work laptop at home, every evening? At home, you are supposed to be resting. Have a rule of taking laptop home only when you expect to use it and that should not be very often. :