sizes of tires

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Re: sizes of tires

Postby Munkypoop99 » 29 Apr 2013, 22:47

I am willing to make the chair more wide due to the rims. Or at least as wide as the arm rest makes it. Not too much more wide , though. But if that is not possible, I guess I can settle for what I can then.
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Re: sizes of tires

Postby ex-Gooserider » 30 Apr 2013, 06:47

Munkypoop99 wrote:
ex-Gooserider wrote:I should point out that pneumatic tires ARE the same as air-filled ones... The WC industry uses split rims and tubed tires, which DO go flat quickly in the case of a puncture. However if you can find TUBELESS tires and compatible rims that you can make fit on your chair, there is much less of a problem with flats...

Barring a gross puncture of the sort that totally cuts the tire open, a typical small object will only give a slow leak - this is part of the nature of a tubless tire. If you use puncture sealing goo inside the tires the way that BM does, you are even less likely to have a problem.

The air filled tires will give you a much softer ride than the solids that the WC industry tries to stick people with.

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they told me those aren't air filled, GRRR! I think foam filled or something. I don't know. But I was originally going to switch to air filled and told them I don't want to anymore, so they said pneumatic, HMMM


Well, there may be confusion, either on your part or the vendors... At any rate air-filled and pneumatic are the same thing, as that is what pneumatic means... However a pneumatic tire can be either tube or tubeless. Tube tires will go flat quickly on any puncture because a tube is essentially a balloon, and will expand away from any puncturing object. Tubeless tires are much less of a problem because the inner layer of the tire that actually retains the air is bonded to the tire carcass, so it can't expand - instead it grips the puncturing object and tries to seal around it, giving you a slow leak. The puncture sealing goo helps even more by filling the leak entirely.

What you are PROBABLY getting judging from what you post is a "foam filled" tire - which is essentially the same tire with a hard foam rubber insert filling it, instead of air. This is what some of us also call a "solid" tire. These can't go flat, but they give a harsher ride than a pneumatic, and have much higher rolling resistance than a properly inflated pneumatic. The tires that BM uses on his chair are actually "under-inflated" which again makes them harder to roll, but gives an even softer ride...

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Re: sizes of tires

Postby Burgerman » 30 Apr 2013, 09:59

They are also tubeless so much lower risk of deflation, and reinforced with Kevlar as used in bullet proof vests so almost impossible to stick anything in the tyre or cut it.

And it is wide, and just 6psi. So rides over grass, mud, sand, snow without sinking and so you don't get stuck. Or very lightly over glass for eg or someone's toes even without it hurting. So they damage floors less too. And these high floatation tyres offer better comfort, and very low pressure on the ground.
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Re: sizes of tires

Postby Munkypoop99 » 30 Apr 2013, 22:29

ex-Gooserider wrote:
Munkypoop99 wrote:
ex-Gooserider wrote:I should point out that pneumatic tires ARE the same as air-filled ones... The WC industry uses split rims and tubed tires, which DO go flat quickly in the case of a puncture. However if you can find TUBELESS tires and compatible rims that you can make fit on your chair, there is much less of a problem with flats...

Barring a gross puncture of the sort that totally cuts the tire open, a typical small object will only give a slow leak - this is part of the nature of a tubless tire. If you use puncture sealing goo inside the tires the way that BM does, you are even less likely to have a problem.

The air filled tires will give you a much softer ride than the solids that the WC industry tries to stick people with.

ex-Gooserider
they told me those aren't air filled, GRRR! I think foam filled or something. I don't know. But I was originally going to switch to air filled and told them I don't want to anymore, so they said pneumatic, HMMM


Well, there may be confusion, either on your part or the vendors... At any rate air-filled and pneumatic are the same thing, as that is what pneumatic means... However a pneumatic tire can be either tube or tubeless. Tube tires will go flat quickly on any puncture because a tube is essentially a balloon, and will expand away from any puncturing object. Tubeless tires are much less of a problem because the inner layer of the tire that actually retains the air is bonded to the tire carcass, so it can't expand - instead it grips the puncturing object and tries to seal around it, giving you a slow leak. The puncture sealing goo helps even more by filling the leak entirely.

What you are PROBABLY getting judging from what you post is a "foam filled" tire - which is essentially the same tire with a hard foam rubber insert filling it, instead of air. This is what some of us also call a "solid" tire. These can't go flat, but they give a harsher ride than a pneumatic, and have much higher rolling resistance than a properly inflated pneumatic. The tires that BM uses on his chair are actually "under-inflated" which again makes them harder to roll, but gives an even softer ride...

ex-Gooserider

I know I am not getting the traditional solid plastic like wheels. But they also rarely get flat so I don't have to worry about that??
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Re: sizes of tires

Postby Burgerman » 30 Apr 2013, 23:00

Wheel = rim plus tyre.

Plastic wheels makes no sense. Tyres are rubber or rubber like. Wheel rims are plastic or metal.

ALL high end powerchairs use metal. Usually aluminium alloy, usually cast and 2 bits so tyres can be fitted easily.

Now, your wheels are metal. Your tyres are rubber. This goes without saying.

Types of tyres.

a) Air filled (pneumatic) tyres with tubes like a bicycle. These are common. Can be grey, or black. Good for range, and can get punctures.
b) SAME grey or black tyres, but filled with a kind of foam rubber. Sold as flat free, or similar. These cannot get punctures. But they give a considerably harsher ride and are heavier, and tend to eat batteries faster. They wouldn't be my choice.
c) TUBELESS air filled (pneumatic) tyres. These are approx. 20 times less likely to suffer deflation due to punctures. As used on my own powerchairs, and all modern cars and fast motorcycles. They work the same as any air filled tyre. Not generally fitted to stock powerchairs. They are much more reliable than tubed tyres.
d) Foam rubber tyres. Only used on toys or really small indoor only chairs. Not recommended!

Air filled tyres can use puncture seal. This is a liquid that seals punctures as you drive about automatically. Works much better on tubeless tyres.
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Re: sizes of tires

Postby Munkypoop99 » 30 Apr 2013, 23:41

Burgerman wrote:Wheel = rim plus tyre.

Plastic wheels makes no sense. Tyres are rubber or rubber like. Wheel rims are plastic or metal.

ALL high end powerchairs use metal. Usually aluminium alloy, usually cast and 2 bits so tyres can be fitted easily.

Now, your wheels are metal. Your tyres are rubber. This goes without saying.

Types of tyres.

a) Air filled (pneumatic) tyres with tubes like a bicycle. These are common. Can be grey, or black. Good for range, and can get punctures.
b) SAME grey or black tyres, but filled with a kind of foam rubber. Sold as flat free, or similar. These cannot get punctures. But they give a considerably harsher ride and are heavier, and tend to eat batteries faster. They wouldn't be my choice.
c) TUBELESS air filled (pneumatic) tyres. These are approx. 20 times less likely to suffer deflation due to punctures. As used on my own powerchairs, and all modern cars and fast motorcycles. They work the same as any air filled tyre. Not generally fitted to stock powerchairs. They are much more reliable than tubed tyres.
d) Foam rubber tyres. Only used on toys or really small indoor only chairs. Not recommended!

Air filled tyres can use puncture seal. This is a liquid that seals punctures as you drive about automatically. Works much better on tubeless tyres.

okay! It's whatever those gray colored ones that come stock on the wheelchair and don't go flat. I guess I assumed it. Based on what I could see since I cannot touch it. My caregiver just told me it feels like rubber, but there is a foam insert and they never go flat. And that is what comes on the new wheelchair by default unless I request something else but I said to go with these ones. Sorry for all the confusion
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Re: sizes of tires

Postby Burgerman » 01 May 2013, 02:09

No prob.

They are stock rubber grey tyres with a foam filling instead of a tube with air. You will have a more harsh ride, and lessened range (but not hugely so) and no puncture worries. I suffer muscle spasm issues and so do not like them. A smooth vibration free ride is important to me.

Grey tyres also go yellow/brown over time as ultraviolet attacks them. And so look a bit old fast. They also do not have the same durability or grip. Because this durability/grip comes from the oils, and resins and lack carbon that is in black tyres. That is the reason that black tyres both last longer and leave marks on certain surfaces. At least when wet. Grey tyres are "non marking" so have these things removed... They wear, age, crumble and go dry over time and so tend not to last as long. Often markedly.
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Re: sizes of tires

Postby Munkypoop99 » 03 May 2013, 20:19

I would absolutely love something close to this on my wheelchair. Does anyone know anything close to this or similar to this, or even just 7 or 8 spokes that might be what I am looking for? Even if I have to go one or 2 inches wider.

http://www.ooracing.com/store/index.php ... uctId=3521
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Re: sizes of tires

Postby ex-Gooserider » 05 May 2013, 05:08

Pretty, but wouldn't work without serious modification, as these have hubs with bearings in them, and are designed to spin freely on a fixed axle. What you need is something more like a car wheel that has no bearings and is designed to bolt onto a hub, or a wheel with a fixed hub that matches the shaft on your motors... You need a rigid, non-rotating attachment to the motors or you will spin them merrily away while going noplace...

You either need to make / have made a hub that attaches to the motors shaft, and has a bolt pattern that matches the wheel of your choice, or find a wheel with an appropriate hub built in. The second choice will be very hard to find, likely just whatever you can get from the chair maker. The first option just requires a good machinist and a shop...

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Re: sizes of tires

Postby Sully » 05 May 2013, 14:36

What BM in a very nice way is trying to tell you is you can only fit 5 pounds of shit in a 5 pound bag. Every dimension that is changed is related to something else. If one could wish these things, then we would have no need to discuss these things. But one thing is for sure, we are all in this same boat together. Door ways are 30" wide commoly with 28+/- usable due to hinges and thickness of the doors themselves.

Burgerman has shown us a very creative way to circumvent many of the obstacles we run into with powered chairs, but there are few shortcuts left after his modifications have been made. Then you have to trade off something to get something. These things cannot be compressed to fit 6 pounds into that 5 pound bag.
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Re: sizes of tires

Postby Burgerman » 05 May 2013, 17:59

Basically you can fit any wheel, on anything. You need to take charge and get the required machining, spacers, hubs, adaptations done or DIY.

Those wheel you link to are bigger diameter. With a small centre for a simple bearing. If you added the type of centre that would fit your powerchair, on a small 8 inch wheel, they would look just like all powerchair rims. No room for long spokes... Theres a reason powerchair rims look crappy.

You need to know WHY you are using a specific wheel. That reason is primarily because it is the correct size diameter and width for the tyres you wish to use. And also easy to adapt or fit to your chosen device.

The "pattern/spoke" design is the very last consideration. And on a powerchair where wheels are small, centre mountings are proportionally large, there really is almost no choice. Because there isn't enough actual material to have any design.

And. You will NOT find any wheels that are simple swap/plug and play. You will likely find wheels on other powerchair that will be the right size ONLY as nothing else I know of uses 300 x 8 tyres.

So if you really want to swap a wheel just to get different shaped spokes (rather than for width, offset, diameter, tubeless capability etc), then this really is your only option. And nobody will notice. I notice fatter tyres, or lower profile on cars for eg. Because its obvious. The actual design of the wheel centre I honestly couldn't care less. So don't really see it. I see its stance, its capability, not its specific design.

I may if it was a set of 20 inch rims on my van, because they are much bigger, wider, with low profile tyres. It allows bigger brakes to be fitted etc. That's what I notice. Nobody swaps rims on a car to put the same size back.
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Re: sizes of tires

Postby Munkypoop99 » 05 May 2013, 21:40

okay, that entirely make sense. I'm just trying to learn here. And the only one I know that I could do the modifications, is me. And now, since that is not a possibility. I know I have to find something that will bolt on, just as you stated. I get my chair at the end of the month. I wish I had the wheels ahead of time. I'm tired of doing nonstop Internet searches that gets me nowhere. Maybe I am trying to bite off more than I can chew. I don't know. :-(
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Re: sizes of tires

Postby Burgerman » 06 May 2013, 02:01

Trust me there's NO better or different wheels of any size other than prides own (still skinny but better) 4 inch wide ones that are just bolt on.

Having said this, its really not that hard to adapt different wheels or tyres and make them fit but a bit of engineering WILL always be needed.

I think the problem is that you really don't understand enough of the basics of engineering or tyres/wheels to do this. If you did, you wouldn't be looking at the wheels spokes/design so much as the sizes, widths, how they fit, and what tyres match etc. Remember that the wheel itself is just the "bracket" of the correct size and shape that allows a specific tyre to be fitted to a specific motor/vehicle/shaft. The look of the spokes if any, is basically a bit of decoration and an afterthought. In the scheme of things its last in the design process. Because its not important.

The reason you cant find a plug and play "alternative wheel" for your chair is because none exist. With the possible exception of another powerchair wheel that just happens to have the same mounting offset, PCD or shaft diameter etc. But that will look much the same as the one you have now. Dictated mostly by its requirements/sizes.
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