ZRA S2 Seat back height dilemma

[petertan]

I know I have posted a lot of questions lately. Please bear with me as I finalize the specs for my ZRAS2. It is the small details that is troubling me now.

The seat back height for my current chair is 16". I sit on a 1.5" cushion. Plus the cushion, I guess I am leaning on a back height of 15".

I spec'ed for integrated push handles rather than fold-down because I need to have assistance to go up on kerbs and fold-down doesn't appear to be able to withstand that on a regular basis.

The adjustable back post for medium height is 13.5" - 16.5" while high is 17.5" - 20.5"

Now that I am getting the Stimulite Classic Sling which is 2-3/4" thick, what would be a good height range for me? Looks like the 16.5" maximum height for medium is borderline low for me while the 17.5" minimum height for high is a tad too high. Please advice. Thanks!

[amyk]

Are the backs measured the same way? If you follow the directions on the tilite form when you measure the back on your current chair, do you still get 16? Most manufacturers have different methods of measuring chair dimensions, making it very difficult to translate from one to the other.

[petertan]

Are the backs measured the same way? If you follow the directions on the tilite form when you measure the back on your current chair, do you still get 16? Most manufacturers have different methods of measuring chair dimensions, making it very difficult to translate from one to the other.

I measured from the rear seat to the top of the back post. Is that the correct way?

[chasmengr]

Is your current chair's backrest height adjustable? If so, play with it a bit to find out what height you prefer.

From a thread about back pain I was having with my new chair . . .

My rule of thumb is that the top edge should be high enough to support your lower ribcage.

When I followed his advice, my back pain went away. I had set my backrest height too low.

[amyk]

Page 5 of the ZRA S2 order form has the measurement
instructions for the seat back height (F) and there's a diagram on page 3

[petertan]

Is your current chair's backrest height adjustable? If so, play with it a bit to find out what height you prefer.

From a thread about back pain I was having with my new chair . . .

When I followed his advice, my back pain went away. I had set my backrest height too low.

I followed your thread about back pain. Good to see that it is solved.

I have no problem with 15". I'd say that it is just nice although I suspect I can go down to 14".

The dilemma I have here is whether to spec the ZRA S2 with the medium or tall back seat height and set it at what height for the Stimulite Classic Sling that I am getting.

The Stimulite has a difference in height from the cushion I have been using and I don't want to set the seat back height too low or too high.

[petertan]

Page 5 of the ZRA S2 order form has the measurement
instructions for the seat back height (F) and there's a diagram on page 3

But that still doesn't address which back seat height I should select for the cushion I will be getting. Will medium be too low and high too high?

[amyk]

What I mean is that you have measured from the seat sling whereas tilite measures from the post. So what you measured as 16 may translate to 15 on a tilite. It's only an approximation on my part, but you should redo the measurement.

Also take into account that the sling version of the cushion may place you a lot higher than you expect. I have a supracore contour sling, and regret buying it.

[petertan]

Also take into account that the sling version of the cushion may place you a lot higher than you expect. I have a supracore contour sling, and regret buying it.

This issue is that I fear most. Sitting with the back rest too high up, or too low. Besides, the height I want is between the medium and high back seat height.

[stephen212]

One of the nice things about using a solid backrest like the Roho JetStream, is that the chair can be spec'd with lower back canes/posts -- the backrest extends above them. The backrest can be repositioned vertically along the solid, non-telescoping posts, so you can dial in the ideal height, and with the lower back posts you can move your elbows backwards without banging into them. Mostly I prefer the support of a solid backrest but these are other pluses you might consider.

[chriZ]

you can adjust the height after... no problems.

[radio_buddha]

Ask away. I'm sure nobody feels like you're asking too many questions.

In regards to the topic, Stephen is right. Go for a lower height and a Jetstream/ADI back.

At 12 inches, you can move from nine to 16.

The thing to keep in mind is where the rigidizer is on the back. That will be a nontrivial stopping point. To go below it would be a radical change vs. whatever you want above it.

I currently have my clamps right below the rigidizer. I guess I got lucky that it happens to be the right spot.

[petertan]

I have thought about rigid backrests but unfortunately, they are not eligible for shipping outside the USA. Even if they are available locally, I am not willing to pay the exhorbitant price to get one.

[amyk]

adi backs from sportaid start at $382, and they do international shipping. that price is for the aluminium, but im sure if you look around you could find the cf. although im not sure of the realistic weight differences.

[radio_buddha]

You could always build your own.