My mom has a bad back from a fall and multiple surgeries a few years ago, but she wants to get more exercise. She's open to the idea of a bike, but her back is her #1 concern. She does not want a recumbent. I was thinking that a cruiser-style bike might work because I'm sure she would ride at a casual pace, but I was wondering if you guys had any advice. She hasn't given me a price range or anything, but I would say she probably doesn't want to go much over $500. I thought about maybe a Trek Lime after seeing one in a different thread today, but I really have no experience in the bad back area, so I don't know if it's a good idea to even put her on a bike at all..

PS - she has a tiny little dog and I have the cutest image of her in my mind riding a cruiser with Maddy (the dog) in a basket on the front!!

May I ask why a 'bent is out of the picture for her? I pulled my back out doing squats, and the next day rode 35 miles with absolutely no pain.

One of the more upright bikes might work- But it all depends on the Back injury. I have a compressed vertebrae and upright puts more pressure on it so I have to stretch out on the bike. Incidentally- I can be in the most severe of pain but get on the bike and ride 50 miles without a twinge. Sitting in a chair will only make it worse.

I have a bad back and have to ride very upright.
I put "riser bars" on my RockHopper. I also raised the stem to the max.
You "might" need longer brake cables. I just barely got by without having to change them.

Try her out on a Bike E, a sort of semi-recumbent. I rented one for a few days last year and enjoyed it. Lots of models available, and I think some are in her price range. Get her to ride it, not just look at it and say "Yuck."
If that doesn't work, how about an Electra Townie or another bike with that kind of frame, "Pedals forward" or whatever it's called. A friend of mine, a 30-year cyclist who's done dozens of centuries, rides one around town and really likes it. The seat is a little behind the crank and low, so she can get both feet on the ground easily but still have full leg extension.

I'm another who says recumbents deserve consideration here.
But before I get into that......

One bike that a lot of people get for casual riding is the Giant Revive. It has an upright position (no hand pressure) and it has a rear shock, that protects the spine from jarring bumps. The downsides I've heard of are that the bike's weight and gearing are far from ideal for anything but casual short-distance riding. A lot of "regular" bike shops are Giant dealers that have one on hand to test out, so it's worth looking at.

Back to recumbents--there is a wider variety of rider positions among recumbents than there is for upright bikes. Some recumbents sit fairly upright, while others are more reclined--and the reason this is important is that a reclined seat means that the spine isn't compressed when you ride over bumps. Also, you won't need padded shorts, and you're far less likely to get saddle pain on a recumbent.

Wizwheels makes an inexpensive tadpole trike ($1400), Sun makes some inexpensive recumbent bikes (EZ-1, $600) and delta trike (EZ-3, $800).
------
If a person has a back injury, they really need to test ride bikes before buying anything. That can be a hassle with recumbents because of the lack of local dealers, but this can make the difference between having a bike she can ride, and not riding anything at all.
~

You might also take her to try out an Electra Townie and see if it works. There's also the Rans Fusion. I think the key here is going to be the patience and openmindedness to try out as many bikes as possible.

She doesn't want a recumbent because she doesn't want to be so low to the ground with respect to cars. Also, they're way too expensive for how much she'll use the bike. Even used on Craig's List it's hard to find a recumbent in decent shape in the $500 range.
Besides, in general, she can't sit for long if there's a back to the chair that she's in. She's much better on a stool or standing up (she has a tall desk that's at her standing height that she works at all day).
Obviously people feel strongly about this, and I don't mean to offend anyone. I put the line in about not wanting a recumbent because I figured that would be the first thing that people would recommend. I wasn't trying to start an argument or anything.
What it comes down to is this: If she's not comfortable physically or mentally with a recumbent, then even if she gets the best one ever made, she's never going to use it.

Probably the same as a lot of us- We want real bikes.

Recumbents are not for everyone- they may enable certain people with injuries to keep riding and some people may actually prefer them- but I am afraid that I have tried recumbents on several occasions and they are not for me.

Now plenty of Bikes out there in the shops and The only way to check them out is to take Mum to the shop and see what types fits Her- Fits her back and she likes. Just remember that a 30 lb comfort bike taht does not ride and fit well is not going to get used. If possible- look at some of the Hybrids around as they are easy to ride.

Have your mom check this trike out. I own one (I'm 61 now) and it's great for
exercise as well as general utility use in town. It's a Worksman PAV that is a
semi-recumbent. The seat is the same height and fit as a ordinary chair which
is great for us "mature" folk's with any sort of ailment. I'm 110% sure Mom
would be comfortable on one if she can ride at all.

While a new PAV may seem to be expensive they are not really for the quality you
get in a Worksman bike. Tough and dependable is a gross understatment. They
are worth every penney you spend on one while being a huge bargain for what
you get.

https://www.worksman.com/pav.html

I have had 2 spinal surgical procedures and have stenosius with nerve damage. I ride a regular road bike 20 miles a day. It hurts alot but I keep doing it for the abscence of pain and for a workout. A roadbike with that slight hunched over position takes weight off my spine and feels OK.
I do not suggest doing this w/o first checking with your Dr. I would also take no ones advice on this forum except maybe for Dr. Pete.
Everyone is different.

Four years ago I was told that due to my bad back I would never be able to ride a DF bike again so I switched to recumbents. I have owned 3 and love two of them. However I like to tour and shipping a recumbent across country is very expensive. My LBS said they could make a LBS work for me and they did by installing a stem extension and installing anextended seat post with suspension. I sit straighter and no lower back pain. There was a bit of experimenting with heights of both of these components but I now have the sweetest DF ride I've ever had. It's fast, it tours well and it ships cross country for $50 versus the $300 for the recumbent.
Experimenting and trying out different bicycles and geometries are the key

Generally speaking, an upright cruiser style bike is no better than an aero-hunch road bike. When you are sitting upright, your weight and all road shock causes your spine to compress vertically. On a road bike you are stretched out, meaning you are using your muscles, not your skeleton, to support your body. If she plans on doing any riding more than a couple blocks, it might be worth checking out a proper-fitting road bike.

I have you beat by one surgery (strange contest) and I find a road bike easier on my back than an upright bike too. No weight on my spine, and the position means I am catching and fighting a lot less wind.

You have had 3 spinal surgeries? I will not try to beat you on this one...you win!
While riding (20-30 miles) I am OK, it's afterwards that the discomfort and pain comes into play.
Extreme numbness, pain, tingling in my legs which goes right down to my feet.
I don't complain and I don't care. I hate when people ask me how am I doing...I say just fine and you should not care.
90% of the people don't give a sh$#, and the other 10% are glad you have the problem. I also don't wallow in self pity, I just ride my bike.

Well, I've only had 1 spinal surgery. I had 70% of my spine fused together T4-L3 to be specific.

Now to the question on hand. Your mom might want to look at a hybrid. I didn't know how my back would handle a bike, and I wanted to start riding again. So I bought a Gary Fisher Zebrano. It is an upright bike about the size of a road bike with straight handle bars. It has shock absorbers in the front forks and the seat post like a MTN bike. It also had wide tires, i think they were 700 x 42. It was a very smooth comfortable ride even on the bumps.

I sold it last year to upgrade to my current bike because I found my back was a lot stronger than I thought. But the Fisher bike was a good place to start for someone with a back issue.

If you are out bike shopping/test riding, have her try out:
Giant Suede
Trek Pure
Electra Townie

They all have the pedals forward which lets you sit upright, touch your feet to the ground easily, and have good powering in your legs. I ride a Giant Suede with 7 speeds and love it. It looks like a cross between a cruiser and a mountain bike. I ride through gravel, dirt, sand, & mostly pavement without problems. My hip and neck bother me at times from a fall years ago, but bike riding seems to keep me loosened up and feeling balanced. I'm approaching 60 and feel great riding 4-5 times per week.

Warning thread hijack!
First of all congrats for not complaining and not wallowing, people seldom realize how boring they are when they do either.
The second thing I want to mention is that often the body will stop hurting on its own. Four years ago I had a pretty good accident and went over the bars and onto my back, I was looking at a fourth spinal surgery when the swelling went down and I canceled everything. I learned what not to do (things like sleeping on my right side) and eventually was in less pain. These days I have no pain beyond sore muscles, I think those neurotransmitters get tired of sending the (pain) signal and just give up.

You can't make general statements about bad backs!
If I were to "stretch out" for a couple minutes, I wouldn't be able to straighten up the rest of the day.
I HAVE to ride very upright or not ride.

I would recomend an erb (energy return bike). The ERB gives you a Mechanical Pedaling advantage by storing and releasing energy with every pedal stroke. I love this bike.

Umm...any pictures of this ERB? Sounds like it has a transducer system of some type.
I knew some guy named Herb.

https://www.erbbike.com/index.html

The current version of the Slingshot, it seems.

....What would an ERB do for a bad back? The rider position is the same as a normal bike, and it's got no rear suspension (though I guess the frame is rather flexy.....).
~