Straight Sided Tyres
 Straight sided tyres are similar in construction to wired on tyres and have inextensible wire beads. They were developed in the USA and employed either rims with a detachable flange or rims that could be reduced in diameter for tyre fitting and removal.
They were phased out for cars in the 1920s although they are still used on commercial vehicles.
 The top table refers to tyre size and the bottom gives details of the detachable rims.
|
Tyre Size
Information diameters and widths in inches |
Tyre Size |
Overall Diameter |
Inflated
Width |
Recommended
Rim Width |
Max. Load in lbs. |
Revs. Per
Mile |
| 31 x 4 |
31.50 |
4.20 |
2.75 |
900 |
673 |
| 32 x 4 |
32.45 |
4.20 |
2.75 |
1000 |
655 |
| 32 x 4.5 |
33.00 |
4.65 |
3.10 |
1250 |
643 |
| 43 x 4.5 |
34.80 |
4.70 |
3.10 |
1250 |
610 |
| 36 x 4.5 |
36.70 |
4.70 |
3.10 |
1250 |
578 |
| 33 x 5 |
33.50 |
5.20 |
3.75 |
1700 |
633 |
| 35 x 5 |
35.40 |
5.20 |
3.75 |
1700 |
599 |

| Detachable Rim and Tyre Sizes
- dimensions in millimetres except for tyres |
Tyre Sizes |
Outside Diameter |
Inside Diameter |
Overall width |
Inside Width |
18 x 3.5
25 x 3.5 |
492 |
451 |
87 |
59 |
19 x 3.5
27 x 4.40 |
518 |
476 |
87 |
59 |
20 x 3.5
30 x 5.00 |
543 |
501 |
87 |
59 |
21 x 3.5
29 x 4.40 |
568 |
527 |
87 |
59 |
22 x 3.5
32 x 5.00 |
594 |
552 |
87 |
59 |
23 x 3.5
31 x 4.00 |
619 |
578 |
87 |
59 |
25 x 3.5
32 x 3.5 |
670 |
626 |
87 |
59 |
18 x 4
27 x 4.75 |
498 |
451 |
99 |
68 |
19 x 4
28 x 4.75 |
522 |
476 |
99 |
68 |
20 x 4
29 x 4.50 |
548 |
500 |
99 |
68 |
21 x 4
30 x 4.50 |
573 |
527 |
99 |
68 |
22 x 4
32 x 4.00 |
598 |
552 |
99 |
68 |
23 x 4
31 x 4 or 33 x 5 |
624 |
578 |
99 |
68 |
| 24 x 4 or 33 x 4.5 |
649 |
601 |
99 |
68 |
| 25 x 4 or 34 x 4.5 |
675 |
626 |
99 |
68 |
| 18 x 4.5 or 28 x 5.00 |
502 |
450 |
111 |
79 |
| 19 x 4.5 or 29 x 5.00 |
527 |
476 |
111 |
79 |
| 20 x 4.5 or 30 x 5.00 |
552 |
501 |
111 |
79 |
| 21 x 4.5 or 31 x 5.00 |
578 |
525 |
111 |
79 |
| 22 x 4.5 or 32 x 5.00 |
603 |
551 |
111 |
79 |
| 23 x 4.5 or 32 x 4.5 or 33 x 5 |
629 |
577 |
111 |
79 |
| 24 x 4.5 or 33 x 4.5 |
654 |
601 |
111 |
79 |
| 25 x 4.5 or 34 x 4.5 or 35 x 5 |
679 |
626 |
111 |
79 |
| 18 x 5 or 30 x 6.00 |
502 |
449 |
127 |
95 |
| 19 x 5 or 31 x 6.00 |
527 |
476 |
127 |
95 |
| 20 x 5 or 32 x 6.50/6.20 |
552 |
500 |
127 |
95 |
| 21 x 5 or 33 x 6.00 |
578 |
525 |
127 |
95 |

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