Tube dilemma on 4 x 8 Tri Ribs

[Anglo Traction 761]

I need some opinions/advice from some experts/anyone .

We're talking UK based here, but the principles are the same.

I've obtained a pair of 3 Ribs and tubes from an online Farm Supplier. The 4.00 - 8 Tires are ok, if only a little narrow for the size stated.

The Tubes they matched for the tires are quoted as 3.50/4. x 8.

The moment I unravelled a tube, it was immediately obvious to me that it will in no way support the tire as it was way too small (in section and O/D).

I've been in touch with the (helpful) supplier and they in turn have contacted the Distributor. The Distributor's response was that the tubes are correct for the tire, but they queried the size of the Rims I plan to mount them on?.

Correct me if I'm wrong, but would it make any difference if the tire/tube supplied was fitted to a narrower Rim where the inflated tube is not big enough support the diameter of the tire.

Here's a few pics to clarify. Note the Rim (bead) width is 3.3/4" (95mm) . The Tube was inflated to 7psi.

The tube's section circumference is only 25.5 cms and the tube's outside diameter is only about 35cms , so it's well short of adequate dimension to support the tyre properly.

I reckon I would need a tube section circumference of 36cms (inflated) and a tube outside diameter of about 40cms (inflated) to support the tyre properly (the tyre outside diameter is quoted as 42.5cms)...........would you agree ?.

I also reckon they are Wheelbarrow tubes.

My problem will be finding/obtaining them and ensure they are correct size. I have no local suppliers and would have to obtain online.

Any advice will be greatly apprectiated. I've done a search on here, but found nothing to help me..

[1054josh 25]

Most tubes that I've used grow once inside tire. I would mount it and c what happens. The tube is designed to stretch alot before a rupture occurs

[Lars 526]

Richard..

I have the same size tires and tube on my 551.. and that works great. but i think the rim u have there is more wide then the one i have on my burban..

the local tire shop gave me that size of tube to my tires.. and im not quite sure but i think it should be 12 psi in them.. if i dont remember wrong..

i think if u put a bigger tube in ther it wont work to good..because of that size of the tires i think you get to much tube in there..

it can be so large that it remains wrinkle(d) . And over time will damage the tube..

Lars..

[Trouty56 567]

I use the same tire and tube on a c-160.....I like them....I keep em filled pretty hard since there is only the one tread touching. Check the pressure rating on the tire.....

[Kelly 1,030]

You should be fine, tubes can grow 10 times their size before destructing, I've in a pinch used tubes for 4x8 tires in 16x6.5x8 tires with no problems.

[KC9KAS 4,743]

I've seen 15" car tire tubes as big as a tractor tire when kids use them in the snow!

[can whlvr 993]

the rims do look too wide for those tires,but ive been wrong before

[Kelly 1,030]

I put 4x8 tri ribs on the 3.5 " wide rims and they fit fine, now the cheaper tri ribs I have are almost to small but still fit.

[Callen 64]

That's what they should look like mounted

[steve k 82]

That tube is plenty big. They stretch A LOT!!

[Anglo Traction 761]

Thankyou gentleman for your replies. I'll have to get out of the habit querying things that just don't seem correct in my mind. I think I'll return these tubes anyway and find some of better quality. What I failed to include in my first post was that the Valve offset is almost zero. So if I was to fit them, I reckon the strain would be too much together with gross over-inflation.

I've found a site that gives much greater detail/description of their Tubes and will give them a try.

I'll let you know how I get on with this......if your interested?.

Thanks again all.

Regards

[meadowfield 2,650]

Richard,

I see the same thing on the lawn ranger rears. Tube looks like a wheel barrow tube, but after seating with 30psi I'm comfortable that it can handle the distortion. Yet to find any tubes in my horses where the valve actually sits comfortably in the right place without it trying to pull back in.

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