Recumbent trike rental vs grandma's back pain?
 

My mother used to enjoy some short cycling rides, but with age has been suffering from back pain and feels limited to walking about a mile; recently after realizing she'd never use it again she gave her DF hybrid to my sister.

Sister, brother in law, their kids and I really enjoy our local rail trails, when we include the youngest it's pretty relaxed ride in the 8-10 mph range though we might do 10-15 miles.

We have an outfit locally that's dedicated to accessible cycling, and in addition to selling recumbent trikes they rent them for 2 hours use on the local rail trail. Mostly singles, but they also have some tandem trikes.

Speculatively speaking, would treating "grandma" to a rental some spring afternoon be likely to work out? No real expectation of things working well enough to justify buying a recumbent trike, just wondering if it might be a way to include her in an activity with her grandkids.

Or would it make sense to try to rent one of the tandems? And if so, would the independent pedaling be a win over having to follow through? If we all go, there'd be three 40-something adults we could rotate between the tandem power seat and a pair of DF bikes that we can all fit on for at least a kid-paced ride.

Thoughts?

The best reason to have a trike for "accessibility" is because you might fall over. (Iconoclasm aside.) An inexpensive trike is a lot slower than a DF and the ride is not that smooth because the chain stays go straight to your shoulder blades and the frame is made of stout pieces of cheaper steel. I don't think she would keep up and find it fun unless it has a motor and a really fat soft back tire. If she can't contribute much on the tandem it's going to be even slower. Do you think she could manage something like a Pedego?

We're often doing 8-10 mph on account of the younger kid, so I'm not too worried about that - sometimes she only wants to do 6 mph.

This is more of a concern. What I was hoping was that the seat position would be less of a back pain issue, but maybe I'm just imagining that. Rail trail is in pretty good shape apart from the occasional well marked root crack that can be slowed for. But if every little bump is going to hurt, then I guess it's a bad idea.

I've considered suggesting we try the local share e-bikes, but they weigh a ton so I'm a little worried about "wrenching" during incidental handling - there have been some incidents on the sailboat that aggravated things.

Perhaps the shop will let her try sitting on the trike and lap of their parking lot before we decide on the two hour rental.

Prior to the pandemic, I used to take disabled, legally blind folks on bike rides with my semi-recumbent tandem:
https://i.imgur.com/EdljTBX.jpg
https://i.imgur.com/KF9pPSx.jpg
Captain in the rear, steer the tandem.
Stoker is in the front, sitting in the back-supported seat.
Fixed cadence between both riders, but that rarely present much problem.
Full field of vision for both captain & stoker, heads are located within close proximity that you can hear one another with ease.
It may be another option to consider is you want the stoker to keep pace with the rest of riding group.

A noble cause, indeed, and a lot like what the local organization does, and which their rentals help support.

Having the optional pedaler in front does seem like it would make for a nice experience.

But since my mother drives and walks, it's really just the back comfort that's the central issue.

She's concluded riding DF bike just doesn't work for her, what I'm trying to figure out is if a rental [tandem] trike would make it possible for her to join her grandkids on a relaxed pedal of our paved rail trail, or if that's not likely to work either and we'll just have to stick to having her sometimes come along on the daily dog walk while the kids lap us three times if they opt for their bikes.

Maybe I should put it a different way: Anyone give up on riding DF bikes due to back pain but find they can still enjoy riding a bent?

That is me about 20 years ago after injury, I have been riding recumbents since, but still get on my DF bikes.
Tandem helps with those who are willing to come along the ride, but don't feel secure enough to maneuver in traffic by themselves, either unfamiliar with route or else.

Tandems are relationship accelerators; good or bad relationship, a tandem will accelerate it.

Regardless of DF or recumbent, if a person want to ride a bike, they have to be comfortable on the bike.
Having company along the ride will certainly encourage participation for more riding.
My wife started riding recumbent with me about 16 years ago (GF back then):
Just remember, the lower you are to the ground, the better stability the recumbent can offer, but more likely it is to be difficult for someone with back issues to get on and off the recumbent.
Regular 2-wheel recumbents take up less road, more maneuverable, but rider require to balance while riding.
Recumbent (tadpole) trikes are great, very stable, just difficult to transport & take up storage room when not in use.
https://i.imgur.com/Uf0IKPg.jpg

Regarding the rough ride concern, many recumbent trikes use mesh seats, which absorb a lot of shock. Not quite as well as a good suspension system. The biggest issue is the seat height - too high and it's hard to get a leg over the main tube and easy to tip in corners; while too low and it requires doing deep-knee bends to get into and out of. And if what's available for rent is those cheap 1 or 3 speeds, it won't be worth the effort.

I believe a recumbent tandem would be very enjoyable for her. But she may enjoy the easier stability of a recumbent trike over a recumbent two-wheeler. I'd do it!