3.5" tubeless tires

[JoeP]

hi all,

I'm hoping to put a couple of 3.5" wide tubeless tires on my TDX SP to lessen the shock.
I think I stumbled across the tire that BM installed on his BM 1.
(KITACO 8-inches Tubeless Tire [3.50-8 35J] HONDA GORILLA)
https://tinyurl.com/hs9e2ol

As far as I can figure the only way to get them in the US is to have them shipped from Japan.
However, before I commit to that, can anyone tell me what the wheel/ rim measurements would be to fit this tubeless tire?
Does anyone know where to buy such a rim in the US?

Also, is anybody aware of a 3.5" x 14" or 15" diameter tubeless tire sold in the US?

Joe P

[Burgerman]

Thats an uncommon size in the US. There are a few but its common in other parts of the world. You may have to import a couple of sets.

More 8 and 10 inch tyres here:
http://www.shirebikes.co.uk/collections/tyres-tubes
https://www.ooracing.com/store/monkey/tyres.html

[flagman1776]

http://www.extremescooters.biz/3-00-8-tire.aspx 3.00 x 8
https://www.amazon.com/Bridgestone-Scoo ... 36&sr=1-10

It will take some digging through search results. I used Google search "3.50 x 8 knobby tires scooter"

[JoeP]

Thats an uncommon size in the US. There are a few but its common in other parts of the world. You may have to import a couple of sets.

More 8 and 10 inch tyres here:
http://www.shirebikes.co.uk/collections/tyres-tubes
https://www.ooracing.com/store/monkey/tyres.html

Thanks BM, thanks flagman,
Yes, the pickings are slim in the US, especially when it comes to wheels/rims that can be adapted.

BM, what wheel/rim did you use for your 3.5" tire on the BM 1?
Was it the rim that comes with this trailer tire: RS350X8 Spare Wheel for the Erde 102 Trailer
<http://www.erde.co.uk/product/rs350x8-spare-wheel-for-the-erde-102-trailer/>
regards, Joe P

[flagman1776]

http://www.ebay.com/bhp/honda-z50-tires

[JoeP]

http://www.ebay.com/bhp/honda-z50-tires

Thanks Flagmen. I see that these assemblies are tube type tires. But the seller also sells 10 inch tubeless rims.
I contacted him to see if he can supply 8 inch rim-14 inch diameter tubeless tires. Hopefully you'll come up with something.
Joe P

[Burgerman]

I had some cheap steel wheels from a small trailer, I used those. If I wanted prettier lighter ones I would use the monkey bike after market rims.

8 pages of rims here. http://www.minibikecraze.co.uk/monkeybi ... ts/wheels/

As I did here: download/file.php?id=4455&mode=view

These are 10 x 4 wide, with 130/60-10 tyres.

[flagman1776]

I find very often it's a game of playing with the search terms. Those monkey bike wheels look really cool.

[Burgerman]

Which ones? There are lots. Wide tyres always look cool no matter what rims as long as they are wide enough to stretch the tyres!

http://www.minibikecraze.co.uk/shop/whe ... j-tubless/ I used these.

[Heygnow]

Thinking that 3.5-8 is the rear tire size on the older permobil street chair.

Would they fit a standard 3.00-8 chair rim?

I found these on the bay.

http://www.ebay.com/itm/221195512492?item=221195512492&viewitem=&vxp=mtr

[Burgerman]

Any 350 x 8 will fit. Its the 8 part that is rim diameter. But they are not tubeless. And they really require a rim that is 1/2 inch wider so will be pinched slightly. That means a softer ride, and a tyre that is around 1 inch taller overall or 1/2 bigger radius. And 1/4 inch wider each side, which may not matter. But you really need tubeless. And so a tubeless rim to fit them to.

[Heygnow]

Not wanting to sound dumb but............

What are the drawbacks with tube tires?

I would think you could slime the tire tubes without making a mess of the tire.

[Burgerman]

Tubes? Think balloon. Pop... Or if you don't end up with an actual tear, the thin rubber expands around the hole because of the pressure escaping. Theres approx 20x greater chance of deflation according to the Michelin site although they were talking about car tyres.

Think about this. Tubeless, you get a nail in a tyre. It stays in, and in doing it bungs up the hole. In a tube, it may still do, but less likely as the tyre carcase lacks the inner grippy tube type liner material. But it will not seal in the tube as its too thin... Pull it out. Tyre is strong. Hole closes up tight. You may never even know you had a nail in it. It doesn't deflate or does so very slowly. Self sealing. In the tube? No such luck, tube is weak, expands around the puncture... The tube is the problem.

Because of the above, puncture seal (your slime) works 99.99% of the time even on large punctures like a 10mm screwdriver on a tubeless tyre. On a tube, it might work with a tiny puncture if you are lucky half the time...

Why do you suppose big bikes, modern scooters, cars, all have tubeless tyres today?

[JoeP]

As I understand it, if the width of a tire is 3.5”, then the width of the rim should be about 1” less or 2.5”. So for the “Kitaco 8-inch tubeless tire [3.50-8 35J]” (see Ebay listing at https://tinyurl.com/hs9e2ol) I need a ‘tubeless’ capable wheel 8” in diameter and 2.5” wide.

BM’s link to ‘Mini Bike Craze’ led me to Mad Munk’s wheel products. Mad Munk appears to have a wheel that fits the bill: ALLOY WHEEL 8 2.5J BS0068 € 37.19. http://www.madmunk.com/p0/bike-spares/2.htm

The 2.5 refers to the wheel rim width and I presume that the J refers to the rims bead contour which would match the tire’s J bead.

Have I figured this out correctly?

[expresso]

I hope this can be figured out someday - i also want to get new tires rim setup if i can find one that fits the same size of my original tire - if i have to get a spacer made - i do it - where i dont know who would do it - but i think that would be the easy part - hard part is finding a rim tire that fits same size height width - etc,

[flagman1776]

Well, I know moving wheel barrows & lawn carts with soft tires walks the tire / tube around the rim & damages the valve causing a leak. In extreem cases, drag racers, seeking to run very soft tires (wih a lot of power) actually screwed through the rim into the beads to stop the tire from spinning on the wheel.
I can't tell you just where the break point is, but that would be my concern.

I don't think you really want a 1" narrower rim... we used to match tire width & rim width as closely as possible. I think 1" is the max allowed in auto tires. On such narrow tires, I don't think that's accurate.

[Burgerman]

It needs to be about 1/2 to 1 inch narrower than the tyre if its a full tall profile tyre. If its a low profile tyre, the rim needs to be wider for the same tyre width.

For eg my 60 profile 130 wide tyres are ideal on a 4 inch rim. Thats 1 inch narrower. Wheelchair rims are 2.00, 2.25 or 2.5 wide. Ideally for a 3.5 inch wide tyre you want a 2.5 to 2.75 wide rim.

On really low profile like 30% or 40% you need be much more accurate and careful. And be 1/2 narrower than the tyre.

And as usual, it all depends what your aim is. With a tall profile, you can use a pretty wide rim and stretch the tyre some. Or a narrow one and have a softer ride, and more sidewall give.

[flagman1776]

As I recall from my performace car days... we tried to"match" rim width tire width... which I take to be tread width. I chose hesize my 68 RoadRunner came with F70-14. The tread width is 6.55, rim recommendation is 5.5" - 7" so will do an inch narrower rim but only a half inch wider.
I agree with Burgerman's assertion on slime in a tube... probably ineffective.
Shifting now to mobility equipment, which are mostly 2 piece wheels... intended for tubes... Going tubeless is not easy on these small wheels. I wonder just how low the tire pressure can be (for softer ride) without tube walking on the rim?

[Burgerman]

Very. The x5 has 4.5psi. Tubed. We have no power... On my tubeless dray bike I used contact adhesive to fit the tyre. Some used 4mm pointed bolts screwed into the rim edge and the pointy part penetrates the tyre bead.

You cant put a 5.5 inch wide tyre on a 7 inch rim! For a start that 7 inch rim is 7.5 in reality. So 1 inch each side wider than the tyres widest part. Well you could, and some boy racers like that look but you end up with the Wheel much wider than the tyre. EG. https://www.google.co.uk/search?q=STRET ... AH#imgrc=_

You have to remember that a 7 inch wide rim, is actually 7 and a 1/2 to 7 and 3/4 wide. Because the 7J part is inside the the part the tyre fits on. So a 7 inch tyre, on a 7 inch rim leaves the wheel rim sticking out wider than the tyre by 3/8th inch or so each side, and it deforms the tyre side walls. A tyre that has a rim 1/2 inch narrower than the tyre ends up almost exactly the same width as the tyre once the thickness of the alloy edges are added. About 7 to 8mm each side. Also at this point its very easy now to damage the rim on a curb.

Also a calc! http://www.tyresizecalculator.com/tyre- ... calculator

[popschief]

Quote;
I wonder just how low the tire pressure can be (for softer ride) without tube walking on the rim?

If your chair has most of the weight on the drive wheels where it belongs then more sidewall area will afford cushion and a softer ride. Running less than 10 psi let's the sidewall flex. (I run 6 psi or less) As Burgerman has mentioned setting up your seating toward the rear allows the castors to be run flat without much consequence. With flats too numerous to count I've never had a tube damaged from spinning in the wheel. The example of this happening with very heavily loaded wheelbarrow tires or 100+ hp dragsters does not come close to the rolling resistance of our application.
bp

[Burgerman]

100+ hp dragsters

That would be the 20 year old 600cc streetbike you came to watch on!

A modern 600cc bike is a toy, but has around 120 horsepower with stock everything and good for 165 mph... 10.9 sec quarter mile at 128mph.
A modern STOCK QUIET superbike like the BMW 1000RR does:

208ps 199bhp 148,000 Watts
Top speed: 190 mph from zero in 22.02 sec
0–100 km/h: 3.06 sec (62mph)
0–200 km/h: 6.87 sec (124mph)
0–250 km/h: 10.4 sec (155mph)
0–280 km/h: 14.8 sec (174mph and still accelerating so hard you have tunnel vision!)
0–300 km/h: 19.1 sec (186mph)

0-100 mph 5.13 sec
Standing mile (1.6 km): 24.98 sec @ 297.73 km/h (185 mph)

The acceleration is insane. It makes a super-car like the Bugatti Veyron look like a pedal car.
And its only got half the power of my street/drag bike! But its quiet, reliable, easy to ride (once accustomed to getting to 100 in 5 secs! Because its brutal)

Theres a bunch of other superbikes with similar crazy figures. They don't spin the wheel inside the tyre if its fitted correctly. But if you use that white animal fat and a brush that so many tyre fitters use on cars, they will. It rips the beads out of the tyres and costs you for a new tyre if unlucky.

[rlnguy]

I have put some wider tires on, by making a spacer. Shown are some 4.80/4.00-8 tires on 8" rim.
Not tubeless, though.
and, yes, the 3.50 should fit-Permobil used the same rim on Street, as on their other chairs, except Trax and X850.

[flagman1776]

Thanks guys! My looked up data & recollections from the late 60s... and other applications... don't really cut to the heart of the problem like real world data. Real world mobility data is what people need to know NOW!

[popschief]

100+ hp dragsters

That would be the 20 year old 600cc streetbike you came to watch on!

The 100+ was a simple misprint. I meant to type 1000+ hp and was thinking of the 4 wheel kind of dragster.
bp

[Burgerman]

Yes I suspected that!

[JoeP]

I learn one heck of a lot reading this web formum!

I have read that auto tire manufacturers have a specific 'rim width range' on which the tire can be mounted. But Kitaco's product information on its tire is pretty sparse.
http://www.kitaco.co.jp/goods_detail.ht ... 08&filter=
However, this product page does seem to say that an aluminum wheel with a 2.5 inch rim should be used with its DURO DM-1020 T/L 3.50-8/35J tire.

As to air pressure, Webike's product description says:
"Recommended air pressure (for example), weight 70kg = 1.1kg"
But then it says:
"recommended air pressure:
　weight 70kg=110kpa"
http://japan.webike.net/products/372904.html

So what is Kitaco recommending? Is it that every 70 kg requires 110kpa (16psi)?

[expresso]

Hi Joe - very good work -

so this tire along with a rim that fits it - would fit on our chairs maybe - with a custom made adapter - who would make one for us is another job to find - and i guess they would need our old rim to make a proper correct one -

if any of this works out - i will consider this also - i would think it would be a much better tire than our stock ones - better grip etc, i hope - but only on street use - off road - not sure it will help me ?

[Burgerman]

There is no correct pressure, apart from the one that offers YOU the best compromises.

For eg, my tail heavy 4 wheel mobile dyno trailer, had all 4 tyres identical. But the front two were at 20psi, rear two at 45psi. Why? Because the rear ones had a heavier load, stronger suspension, and with the same pressure in both sets it drove like a front drime powerchair!

My van, has 15% lower pressure than the 'correct' pressure, because the tyres are larger cross section, and because its better for my muscle spasm. It drives smoother. Downside? Probably wear the edges faster than the centre and be better in snow, and run a bit hot at 100+ all day...

My super powered bike? 5psi at the drag strip, for grip, 36 psi on the way home for hard cornering and safety at rather silly speeds. But you couldnt accelerate hard or it just smoked it...

Dont look in a book, analyse whats going on, what you are trying to achieve, and use the adjustability to your advantage.

[JoeP]

Hi Joe - very good work -

so this tire along with a rim that fits it - would fit on our chairs maybe - with a custom made adapter - who would make one for us is another job to find - and i guess they would need our old rim to make a proper correct one -

if any of this works out - i will consider this also - i would think it would be a much better tire than our stock ones - better grip etc, i hope - but only on street use - off road - not sure it will help me ?

Hi Claudio,

I would think that this 3.5" Kitaco tire would not be suitable for off road. To smooth & slick. But the manufacturer advertises it is being "grippy".

Yes, we will have to have adapters made. We will have to track down a NYC / Metropolitan area machinist who won't bankrupt us.

I stumbled across a good-ol-boy machinist down in Missouri who does lots of work on modifying garden tractors for mini "tractor pull" contests. Looks like an interesting & eccentric hobby. Maybe we can turn this newfound knowledge into a wheelchair pulling hobby. Lots of mud & girls in bikinis!

[expresso]

I am considering this for my other. Chair to start with. I know I have to cut my fender off to make room for tire. Fender is one piece all together with the battery case. I can't just unscrew it. Would need it removed and cut off. Then put cover back. Leaving me the room to inspect what cN be done. Have to take pictures first to post here for ideas. I like to buy a used one on eBay and use that to. Cut etc don't know where to start with this for real I. Clueless with the tire size I'm etc offset spacers adapters gizzz getting heat stroke already