Q710M faulty suspension --- Q700M revised Suspension better?

[SP3_NYC]

I've owned a Q720m & a Q710, both with tilt, lift, recline, power legs and 8 mph package (I'm 120 pounds; it's worth it for me.)

It appears to be identical to the chair marketed as the Jive M. There are other *similar* versions, that have junkier parts, and the Pulse 6, which is a simpler, lower-end version.
These do climb curbs like this: https://www.youtube.com/watch?v=UxqvTBHknzA
And it can do all this: https://www.youtube.com/watch?v=XtbSipBS900

My body and nervous system can't tolerate the jolts of a typical powerchair. I had to refuse an Invacare TDX-SP a decade ago after going into shock and spasm from a brief spin outside in one.

The Quickie 710m was a infinitely smoother; it was a literal dream. The problem: faulty suspension. In 10 years, I can't count the number of times the gas/oil struts responsible for the smooth ride have failed, often during installation or under light use.

The original struts would just pop and there'd be a small splotch of oil on the ground (happened on day two with the first chair.) Then the chair would behave in a variety of subtle of wild ways.

The manufacturer, Sunrise has 'upgraded' the strut/dampener several times over the years, even switching companies-- each time the ride quality got bumpier and harsher while only slightly improving durability. Failure rates at installation never improved. The system was very, very expensive, and time consuming to replace (especially after being driven for months collapsed or leaning to one side!) and required the installer be skilled, practised on the particular suspension AND LUCKY. I was recently quoted $3,700 to do just the suspension job, much of this for parts!

My dilemma: I have no mobility currently for quite some time (a long story), and insurance and vendor are offering me the direct successor and nearly identical appearing Q700M –they’ve said it’s that or nothing. I wasn’t going to take it as the chair has had me sidelined, almost no-one wants to repair them.

Worse, the chair almost got me killed by going from partial failure that I’ve had to drive hundreds of miles and many months in on numerous occasions. This time the DME ‘lost’ my service request several times. I started my normal commute (I live on the top of a small hill) when the chair suddenly became %100 unsteerable, uncontrollable, and there was no way to stop or slow down. The front and rear casters were spinning madly, the swing arms up in the air or bouncing on and off the ground; the chair was pitching in every direction. I chose to dive out before getting thrown, though the chair bucked me before I could clear, once my hand left the joystick.

I’m considering taking the chair after seeing that they’re advertising a “completely redesigned” suspension (marketing it as Sure Grip Pro). All I can learn is that they’re using a new manufacturer for the coil spring/ dampening strut. I can see from the schematic on Sunparts.com that they’ve simplified some of the very poorly designed rear swing arm.

How can I figure out if they’ve finally done a good enough job? Or if they’ve just found a way to keep selling a fatally flawed product? There were several revisions in 2022, but the Sure Grip happened Spring or June of 2023.

Totally Normal demonstrated on his Youtube channel that the Quantum Fore front shipped with the suspension struts in full extension in the resting position-- I don't think that's the issue here, but have no intact chair to test. I do have a lot of photos of both my chairs jacked up, can check if the casters descended.

Any ideas on how I can suss this out, and fast?

This has been the greatest stress of my life for the past year plus; I can't believe I'm posting this ...
Thank you to anyone who read through this.

Best Regards,

~S

[Burgerman]

At least over here the Jive was a similar looking chair but totally different design. The Jive and the Salsa are the same chairs basically but the jive was a higher spec. Although if you tick the same options on the order form there wasnt any real differences. I actually still have a salsa/jive chair. Albeit the rear drive option. I have a Q700R and a Salsa. So can compare the two directly. The Salsa/Jive is a etter chair wth more rigid seating etc. Both have the same basic motors/control systems, lift, tilt, recline, power centre footrest etc. In mid drive variants I suppose the same applies. But I dont see many mid drives here where I live. Mostly rear drive. Which isnt available in the US. Never had any isues with the suspension on either chair. But it doesent do much...
The suspension failing has been a similar problem on the mid drive Q chair over here according to Rover on here who is one of those rare things, a tech guy that actually knows what he is doing!

Maybe he can enligten you as to if they finally fixed this issue. As for fixing it its just a matter of swapping out a suspension strut. A couple of bolts. And these shocks are not very expensive. So any keen teen that works on a bike can easily swap a pair. They are £112.30 uk pounds for a set of 2 at full retail price. (About 130 dollars a set?) Thats for the "performance" spring as they call it. Its an upgrade over the pre 2022 ones too. So if the new ones fail its not that expensive to repair it. And still have a spare one on the shelf... The other various ones are slightly cheaper.

[rover220]

At least over here the Jive was a similar looking chair but totally different design. The Jive and the Salsa are the same chairs basically but the jive was a higher spec. Although if you tick the same options on the order form there wasnt any real differences. I actually still have a salsa/jive chair. Albeit the rear drive option. I have a Q700R and a Salsa. So can compare the two directly. The Salsa/Jive is a etter chair wth more rigid seating etc. Both have the same basic motors/control systems, lift, tilt, recline, power centre footrest etc. In mid drive variants I suppose the same applies. But I dont see many mid drives here where I live. Mostly rear drive. Which isnt available in the US. Never had any isues with the suspension on either chair. But it doesent do much...
The suspension failing has been a similar problem on the mid drive Q chair over here according to Rover on here who is one of those rare things, a tech guy that actually knows what he is doing!

Maybe he can enligten you as to if they finally fixed this issue. As for fixing it its just a matter of swapping out a suspension strut. A couple of bolts. And these shocks are not very expensive. So any keen teen that works on a bike can easily swap a pair. They are £112.30 uk pounds for a set of 2 at full retail price. (About 130 dollars a set?) Thats for the "performance" spring as they call it. Its an upgrade over the pre 2022 ones too. So if the new ones fail its not that expensive to repair it. And still have a spare one on the shelf... The other various ones are slightly cheaper.

The rwd versions were the same chassis but the jive had more adjustable seating. The mwd variants were very different.

The gas springs on the rear of a jive/q700 have been notoriously problematic. No idea yet if the new version is actually any better.

[SP3_NYC]

@Burgerman
Thanks for reading, it means a lot to me.
I'm sure I just didn't provide enough information. With all due respect, I've owned the chairs for 11 years, and have done the repair in question myself. I, too thought that the strut could be replaced as soon as it fails (by me), thus avoiding having to use a mallet to get all the bent metal of it's articulating SpiderTrack legs apart to replace them. That occurs if the chair has been driven for months before the repair.

Sunrise just revised the suspension and it appears that one can now simply replace the strut as you say. Prior, one had to remove the motors and a dozen or more non-reusable fasteners (high tension, critical Nylocks with blue locktight, fancy (e.g. $33 US) set screws. Much worse, the struts must be screwed into a 1/2 thick receiver held in a clavis. Unfortunately, the correct position to do this in is with the the entire back swing arm raised upwards until "clear of the base mount boss."
That position is impossible without releasing a stupid pin and wire underneath the rear caster housing, which allow removal of thick,curved "brass pad", behind which is "brass spring" in a small anti-seize filled compartment in the cast-metal shell of the rear link arm. The lower side of the strut bolts on, but first the upper must be turned to the exact specs (which are a bit hard to see when doing), and this MUST be done with their $77 dollar"wrench block assembly -- or you'd neede to machine a similar part. I promise you, I can improvse almost any basic mechanical thing with minimal tools--not this. The top of the strut has a protruding rod, within which is a pin/piston that must have correct pressure and placement against the opposing brass pad, brass spring, and wire retained rear caster arm. Sorry if it's hard to describe! It's a TERRIBLE system, and you really can't instal correctly without replacing all these parts. And, the struts (and other parts) are not kept in stock by the vendors here--never(!), and have frequently been on backorder for weeks. Then surise ships parts in it's own sweet time...

If you know how to find compatible (or better) shocks to replace the latest version (or the previous) please clue me in. The old ones were made by or branded Stabilus, and I believe they were fairly customized to the chair, though I think underspeced for the loads. I was unable to identify the strut specs, either, they appear to be obscured on purpose.

This is the new part, #25598 https://www.southwestmedical.com/replac ... 55989.html

In the version as of June 2023, it appears that one can now just change the strut (unsure if you need to remove the motor-- there has been no obtainable service manual since 2012.) I'm highly encoraged by that change!

As for costs, the struts are now $450 a piece retail and really must be replaced as pairs. I'm curious at the

£112.30 uk pounds for a set of 2 at full retail price

The current part number is 255989 SHCK REAR CSTR ARM 99MM
http://sunparts.us/partscatalog/template/index.php

Excerpt from an adverse (MAUDE report) on the FDA's website:

Manufacturer Narrative
....this wheelchair includes a suspension spring which is used to allow the user to navigate variable terrain while maintaining steering and drive control and consists of a cylinder with an internal fluid-pressure system.The spring can experience loss of pressure by failure of one or more internal seals that control pressurized fluid (leak) or through the failure of the spring pin in the unlocked position.Such a loss of pressure can result in the user experiencing forward pitching of the chair and/or veering to the side when decelerating.Although not reported here, the potentially severity of the matter could include the user being thrown from the chair which could lead to an injury.

The potential failure mode and subsequent effect would be detected in time for adequate intervention if the user followed the proper maintenance checks outlined in the owner's manual.This risk has been mitigated to its lowest possible level, and removal of the spring may reduce drive control and lessen steering capabilities, which could create a greater risk to the user's safety.Quickie qm710 owner's manual, page 8: "although equipped with suspension, the performance can be substantially reduced on uneven surfaces and rough terrain." discussion: although the wheelchair has not been evaluated in person, a probable root cause for the chair pitching forward and backwards more than normal could be due to a malfunction with the suspension spring activation pin.The quickie qm710 owner's manual notes that the suspension performance can be reduced on uneven surfaces, which could also be the cause of the pitching forward and backwards the patient has allegedly felt when going up and down ramps as mentioned.While the risk level is low, it has been determined through a failure analysis that should this be a malfunction with the spring and should the malfunction recur, it could possibly result in serious injury.T

There are other reports including death. They vastly understate the concern, that catastrophic failure as occured to me is perilous (and I have fast reflexsed and am an ex gymnast & diver-- most users would have sustaind a worse injury; I solled and didn't hit my head, but by brain banged against both the front and back of my skull and suffered a life-altering concusion) and the manufactrurer has know the entire time (since 2012 at least) that the produch fails consistently and severely, often before installation is complete. It fails under light and cautious use with no clear assault to the chair. Yet they cuntinue to market it as even as an all-terain chair(!) in some countries. The videos of drivers going over uneven cobbles, and of climing up and down curbs, making rapid circles over obstacles and speedbump-- will lead to speedy failure.

You see why I'm terrified of being stuck with this chair again? I will never be in that danger, as I now know how deadly full suspension failure is. The company won't answer what the've done to improve the safety, nor name the new manufacturer, show a picture of the strut, nor give any quantitative or qualiltative information about the new struts or the redesign, including whether they've made it safer when it fails. My main concern is having another lemon, where the parts are super expensive, hard to get, and I void my warranty and service contract if I install a strut myself to avoid crushing and mangling the caster arms/link arms and other parts when the chair's weigh falls to one collapesed side (the other side ususally then fails due to stress).

I've been researching fasteners (since the manufacturers don't give up the information to "end-users", and now know enough to source most of the correct ones for the critiical high vibration, high load ones retail for around 1/100th of manufacturer's suggested price or less-- but that, again, means forgoing insurance funding and labor. I'm severely disabled, but able to squeeze enough out of myself, with extensive bracing (self-improvised), and some toll on my body. I understand levers, and find ways to do anything.

BTW: What size image can I post, and how? I don't have image hosting set up, haven't joined a forum for a decade or more. I can share google drive links?

[Burgerman]

Yes. But remember that I for e.g do not have a google account. Because I understand the web...

Any old bolts are fine. I throw away all the high tensile steel ones and replace them with stainless steel for 24 years. Same with bearings. Then they do not corrode and come apart as if it was new decades later. Provided you also grease them on assembly.

Look up the strengths of various bolt sizes. You will see that the weakest ones (softest grades) and stainless, are still 10x stronger than we ever need.

[martin007]

I have always thought that powerchairs of 6 wheels only give problems.

[SP3_NYC]

@rover220, @Martin, Burgerman --thanks all for reading and chiming in.

Honestly, I read that Sunrise/Quickie markets their chairs under, somthing like 27 different brands worldlwide. What I can say, with very little doubt, is this Jive M is my chair, at least in the videos I've seen.

I asked to see the new revised Quantum R-Trak (despit the programing issue), since it's the only non-barriatric, rhab capable RWD available here (unless you jump in price to Bounders and Magic Mobility.) Magic mobility here cost and extra $13,000 USD, don't know current prices for bounder.
The R-Trak looks suspiciously like the old Forefront, but turned around (I believe someone here said that too, but it would occur to anyone familiar with the Forefront.
However, even this video from 2022 shows a meaningful suspension (if very springy), and supposedly the recently revised it to provide "more comfort" (i/e/: to provide any comfort.).
But my Vendor and Insurance only want to give me the defective chair.
I'll do a freedom of information act request with our regfulatory body, the FDA, but that take over 45 days...

Any tip or questions I could ask to help me suss this out? Alternately, if I can demo one, anything I should look for? IF the strut is still bad or underspeced, do you know of ways to source better product that is compatible? If it's the vectors and design that are to blame as well, would any post-market mod fix it?

If no-one knows, I surely understand!

I've shopped for the discontinued Quickie 636, or perhaps preferably the 346 that comes with possibly interesting front suspension caster forks. My concern is that 1)people are selling chars that have sat around, some since 2017 and calling them 'new' -- chair definitely deteriorate in less time then that, particularly if they never move, as do some components. 2) I can't get answers about parts availability (the series was technically discontinued in 2021, and Sunrise guarantees parts for 5 years after, but only while availability lasts!! Nice support! If I buy one of those, I'd first get a quote for shocks, bearings, bushing, caster forks, etc and purchas prior to need if available. Do you think the 646 0r 636 is stilla good idea (I prefer RWD, and would rather service them, plus much more mod-friendly). I see them selling for $4-6k on ebay--I think thatt's steep...thoughts?

Regards,
~S

[Burgerman]

Well since you like rear drives this may interest you. I bought a rear drive Q700R on ebay, £4200 (under 5k dollars) with under 9 miles on it. Never been sat in. Just delivered, then returned to a dealer 3 days later. It has 120A controller, Gyro that it doesent need so its disabled (like me!), CJSM2 joystick, centre power footplate, lift, tilt, recline, and I modded it very slightly. It has front suspension so better for my spasm, seat moved back to make for a shorter and more agile chair, properly programmed, and it has smaller fatter front caster tyres, and wider 120/70 - 8 rear tyres on widened rims.

Its nt as good as the salsa. Which has exactly the same specs! Thats a more rigid better driving chair. But only slightly. Both have fat rear tyres that improve the ride as well as either 10 inch front casters or front suspension to make the front end smoother.

Take a look.
The salsa is absolutely as brand new. I bought it brand new (under 6k with some discount and zero VAT). And its now a 2017 chair. Only sees sunshine! And I maintain and clean my chairs. Tell me what is it that you think deteriorates in 6 years? Sat. Nothing that I can detect! Some of my chairs are absolutely as new 10 or even 20 years after building them.

And heres a couple of threads with both of them.
Salsa 6k brand new: https://www.wheelchairdriver.com/board/ ... 00#p122818
You will need to read and then scroll down.

Q700R with front suspension basically unused £4200 eBay... https://www.wheelchairdriver.com/board/ ... 33#p171026
Again many small mods to make it a better chair.

[Burgerman]

Theres also this. I think this has the best ride of any owerchair I ever had.

£5700 new. Also lift, tilt, recline, power centre footplate, and so on.

This is invacare. Its another rear drive you guys never saw in the US unfortunately. The Invacare true track Xplore.

[Fusiongoat]

Your insurance company can't really tell you which chair to get. They can only limit you to certain types e.g. group 3. If your ATP won't agree to a different chair, demand a different ATP. If that doesn't work, switch to a different DME company. You could try this chair for ride quality https://www.sunrisemedical.com/power-wh ... ll-terrain
Sunrise now claim that chair is group 3. The Permobil F5 also has very good suspension. If you can get a a prescription for a chair, but insurance won't covver it, then file a complaint with your state division of insurance https://askjan.org/resources/New-York-D ... rvices.cfm
Also, try to get a free attorney.

I've owned a Q720m & a Q710, both with tilt, lift, recline, power legs and 8 mph package (I'm 120 pounds; it's worth it for me.)

It appears to be identical to the chair marketed as the Jive M. There are other *similar* versions, that have junkier parts, and the Pulse 6, which is a simpler, lower-end version.
These do climb curbs like this: https://www.youtube.com/watch?v=UxqvTBHknzA
And it can do all this: https://www.youtube.com/watch?v=XtbSipBS900

My body and nervous system can't tolerate the jolts of a typical powerchair. I had to refuse an Invacare TDX-SP a decade ago after going into shock and spasm from a brief spin outside in one.

The Quickie 710m was a infinitely smoother; it was a literal dream. The problem: faulty suspension. In 10 years, I can't count the number of times the gas/oil struts responsible for the smooth ride have failed, often during installation or under light use.

The original struts would just pop and there'd be a small splotch of oil on the ground (happened on day two with the first chair.) Then the chair would behave in a variety of subtle of wild ways.

The manufacturer, Sunrise has 'upgraded' the strut/dampener several times over the years, even switching companies-- each time the ride quality got bumpier and harsher while only slightly improving durability. Failure rates at installation never improved. The system was very, very expensive, and time consuming to replace (especially after being driven for months collapsed or leaning to one side!) and required the installer be skilled, practised on the particular suspension AND LUCKY. I was recently quoted $3,700 to do just the suspension job, much of this for parts!

My dilemma: I have no mobility currently for quite some time (a long story), and insurance and vendor are offering me the direct successor and nearly identical appearing Q700M –they’ve said it’s that or nothing. I wasn’t going to take it as the chair has had me sidelined, almost no-one wants to repair them.

Worse, the chair almost got me killed by going from partial failure that I’ve had to drive hundreds of miles and many months in on numerous occasions. This time the DME ‘lost’ my service request several times. I started my normal commute (I live on the top of a small hill) when the chair suddenly became %100 unsteerable, uncontrollable, and there was no way to stop or slow down. The front and rear casters were spinning madly, the swing arms up in the air or bouncing on and off the ground; the chair was pitching in every direction. I chose to dive out before getting thrown, though the chair bucked me before I could clear, once my hand left the joystick.

I’m considering taking the chair after seeing that they’re advertising a “completely redesigned” suspension (marketing it as Sure Grip Pro). All I can learn is that they’re using a new manufacturer for the coil spring/ dampening strut. I can see from the schematic on Sunparts.com that they’ve simplified some of the very poorly designed rear swing arm.

How can I figure out if they’ve finally done a good enough job? Or if they’ve just found a way to keep selling a fatally flawed product? There were several revisions in 2022, but the Sure Grip happened Spring or June of 2023.

Totally Normal demonstrated on his Youtube channel that the Quantum Fore front shipped with the suspension struts in full extension in the resting position-- I don't think that's the issue here, but have no intact chair to test. I do have a lot of photos of both my chairs jacked up, can check if the casters descended.

Any ideas on how I can suss this out, and fast?

This has been the greatest stress of my life for the past year plus; I can't believe I'm posting this ...
Thank you to anyone who read through this.

Best Regards,

~S

[SP3_NYC]

@Fusongoat
I apreciate the reply. I'm a tenaciaous and resourceful person, or would not have survived.Good info, but nothing new, and none applies to my situation (except, yes, I have medical necessity and prescriptions.) I cannot post more particulars in an open online forum-- to protect my identity, and, other reasons....

If anyone knows a lawyer willing to take on gross failure to uphold duties and flagrant corruption in public insurance by the two largest industry controling DME vendors, or a large Airline...DM me, please (I many have a Qui Tam case or two...)

If anyone has as much or more insight into mid-wheel drive suspensions, I need your help. I'm %100 sure the design and materials of all these 710,715,720M and the 700M chairs sold in the US prior to this June were faulty (unsure if the problems were reduced any in the later version; they certainly were not resolved prior to the recent revisions.

They've made significant changes, but I don't know how to figure out if they chair is no longer an expensive disaster.

@Rover-- any insight? PM is fine
~S

[SP3_NYC]

Those supposed to help and serve are making billions, are lawyered up, and play dirty hardball with disabled people they've left confined to bed. at the expense of taxpayers.

[Burgerman]

Those supposed to help and serve

Define "supposed"?

Each is a business. Every business from manufacturer or one man band, exists to make a profit. They dont start businesses to "help and serve". That happens to be a by product of what they do. And in a NON free market NON competitive enviroment the result is that they dont need to serve YOU and prices will be telephone numbers. No competition. Thats what you have got. Venuzala style system.

In a fully free market system which works great to bring the lowerst cost and best products and best service for a consumer. Thats why you can buy a car or computer or whatever with the latest high tech specs, at very competitive prices. And the salesman CALLS YOU with an offer. It works because of free market competition. That brings good service and low prices on the products YOU want. Or you go elsewhere.

In the US the wheelchairs are massively over legislated and the market is far from free. Unlike other goods. Its a heavily distorted and controlled market where YOU are not the cash waving customer. No free market means no choice, low value for money and terrible service.

Remember that in the UK our low spec basic wheelchair market is NHS (socialist) controlled and "free" at the point of access. But again its DISMAL in its options, choice or value as the NHS is hopeless and costs us 20.6% of the entire national income to prop up. So that "free" comes at a huge real cost.

When it comes to high spec chairs such as my 3 chairs above, all with high end controllers, 4 pole motors, tilt, lift, recline, power legs etc these are generally bought by end users (YOU) and are free market high street purchases. As such I paid under 6k for the salsa, under 5k for the Invacare one, both brand new. And 4,200 for the "used" but never sat in Q700R rom a dealer and all with every expensive option ticked. Because thats the REAL free market price if you haggle a bit. (add 20% for dollars.)

It also mean we can buy parts online or any high street dealer. Because WE are the ones waving the £££$$$ around not the NHS or some insurance company. Its the end user that they have to satisfy and deal with. And sell to. This means market competition. And best price/service/options means a sale £££.

[Raro]

Hello, I stopped by just to give my experience, they gave me a Jive m chair from 2016, this chair came with the rear shock absorbers burst, causing the chair to rise on slopes like a horse, these first versions did not have shock absorbers in the front arms or springs in the rears. As you say, there have been update campaigns. I used one of them and the truth is that the chair now behaves perfectly. What I don't know how to tell you is the durability. The set cost me €250.

This note explains and there are videos for the installation of the kit.

https://www.sunrisemedical.co.uk/suppor ... e-m-update

[Raro]

An image of the kit I installed

[Raro]

A video of what a Jive chair does when it has bad shock absorbers.
https://youtu.be/1AfsW_QS81Q?feature=shared

[Red Dragon]

I have the JIVE M chair. The rear shock absorbers have been replaced twice. Last time they replaced them with a rear shock absorber with a reinforced spring. The chair is uncomfortable. The shock absorber does not function well. The problem starts with the front bushing that the technicians remove. I am considering choosing the Permobil M1.

[Raro]

From what you're saying, you have the upgraded shock absorber version, but make sure you have shock absorbers on the front axle, the red ones in the image above.

[Raro]

It's actually important to change the whole kit because it worked really well for me, although I've barely used it, so I don't know how long it will last.

[Red Dragon]

They didn't agree; they claimed it’s a different model that isn't supposed to have a spring, even though there’s a place for one. It has an upgraded shock absorber, but it doesn't provide any cushioning—it just feels stiff. Anyway, I’ve already ordered a new chair. We'll see how long this one lasts.

JIVE M to Q710M .

[Burgerman]

You realise that if we ignore the front and rear arms, that only serve to hold your mid wheel chair upright, that all of tha chairs mass, and you, are sat ONLY on the drive wheels.

And here theres either no or almost no suspension travel at all on those.
And both the rear or front arms dont change that. Those just serve to keep a 2 wheeled bar stool upright. Any bump you run over with the main drive wheels transfers all of that bump (or almost all of it) directly to your spine.

The front and rear "suspension" isnt suspension at all. It isnt supporting your mass at all. It serves only to hold the middle bit (that you are sat on) upright. Those arms are sprung into the floor. Any shock or bump they see/hit serves only to rock the chair back or forwards IN PITCH.

[Red Dragon]

There is also a small spring behind the motor, connected directly to the engine assembly. Many technicians lack the specialized knowledge to diagnose and repair it, or they are simply too lazy and cost-conscious to do the job right. They often don't take the time to see the repair through to the end. While it's true that a Rear-Wheel Drive chair is much simpler, the superior maneuverability of a Mid-Wheel Drive chair—both at home and in a vehicle—makes the extra maintenance effort worth it.


The TDX SP is engineered for superior balance on challenging terrain. Its integrated G-Trac gyroscopic system ensures straight-line tracking on ramps, while the Stability Lock mechanism prevents forward tipping, keeping the chair remarkably stable during steep descents.

[Red Dragon]

The Invacare TDX SP series uses SureStep® suspension and Stability Lock to keep the seat level and the wheelchair balanced when descending a ramp.

[Raro]

The front shock absorbers are necessary to prevent what you see in the video above. Without them, on any ramp or slightly steep incline, all the weight will shift to the rear shock absorbers, causing them to break prematurely. The small bronze blocks also limit the suspension travel. Read this and watch the four videos inside if you haven't already: https://www.sunrisemedical.co.uk/suppor ... e-m-update

[Raro]

The kit eliminates chair wobbling.

[Burgerman]

There is also a small spring behind the motor, connected directly to the engine assembly. Many technicians lack the specialized knowledge to diagnose and repair

The TDX SP is engineered for superior balance on challenging terrain. Its integrated G-Trac gyroscopic system ensures straight-line tracking on ramps, while the Stability Lock mechanism prevents forward tipping, keeping the chair remarkably stable during steep descents.

My freind who lived close had a TDX SP and I drove it a lot. It was an awful harsh ride on the stuff that we have around here. It crashed over every uneven bump horribly. And steered like a hovercraft. That true track thing doesent improve it at all. It attempts to cover up a chair thats programmed like a hovercraft. And it has almost no torque when you want it, and kicks in after you did. If you program it PROPERLY so that it actually steers ACCURATELY and disable the gyro its way better.