Wheel & Tyre Sizes 2026
Beaded Edge
820x120 Ensign Dia O/A 828mm Rim Diameter 609mm
Blockley Dia O/A 820mm Rim Diameter 608.6mm
(Dunlop) 826mm (Rim Diameter 566mm, presumed measured differently)
880x120 Ensign Dia O/A 881mm Rim Diameter 672mm Section 4.76"
Blockley Dia O/A 885mm Rim Diameter 672.2mm Section 4.77"
(Dunlop) 889mm (Rim Diameter 663mm, presumed measured differently)
895x135 Ensign Dia O/A 886mm Rim Diameter 634mm
Blockley Dia O/A 890mm Rim Diameter (608.6mm? Blockey info presumed incorrect) Section 5.59"
(Dunlop) 886mm (Rim Diameter 590mm, presumed measured differently)
Cross referenced with the Dunlop/VTS guide from 1975 for Dunlop sizes. While the actual rim dia figure from Dunlop does not tally with Ensign, the differences in rim diameter between 820 880 and 895 are exactly per Dunlop spec. Therefore, an 880 rim is in fact 40mm larger in diameter than an 895 rim despite the overall tyre diameter being essentially the same. A much higher sidewall to keep the same ratio for the extra section.
Well based
21" Blockley 525/600 5.91" overall section, 838mm Diameter overall
Blockley 675/700 7.32" overall section, 889mm Diameter overall
Michelin DR 5.50/6.00 6.8" overall section, 861mm Diameter overall (still NA 18.1.26)
20" Blockley 650/700 7.28" overall section, 870mm Diameter overall
Blockley 475/500 5.51" overall section, 775mm Diameter overall
Michelin DR 6.50/7.00 7.6" overall section, 866mm Diameter overall
With thanks to Jonathan Bailey Jan '26
820x120 Ensign Dia O/A 828mm Rim Diameter 609mm
Blockley Dia O/A 820mm Rim Diameter 608.6mm
(Dunlop) 826mm (Rim Diameter 566mm, presumed measured differently)
880x120 Ensign Dia O/A 881mm Rim Diameter 672mm Section 4.76"
Blockley Dia O/A 885mm Rim Diameter 672.2mm Section 4.77"
(Dunlop) 889mm (Rim Diameter 663mm, presumed measured differently)
895x135 Ensign Dia O/A 886mm Rim Diameter 634mm
Blockley Dia O/A 890mm Rim Diameter (608.6mm? Blockey info presumed incorrect) Section 5.59"
(Dunlop) 886mm (Rim Diameter 590mm, presumed measured differently)
Cross referenced with the Dunlop/VTS guide from 1975 for Dunlop sizes. While the actual rim dia figure from Dunlop does not tally with Ensign, the differences in rim diameter between 820 880 and 895 are exactly per Dunlop spec. Therefore, an 880 rim is in fact 40mm larger in diameter than an 895 rim despite the overall tyre diameter being essentially the same. A much higher sidewall to keep the same ratio for the extra section.
Well based
21" Blockley 525/600 5.91" overall section, 838mm Diameter overall
Blockley 675/700 7.32" overall section, 889mm Diameter overall
Michelin DR 5.50/6.00 6.8" overall section, 861mm Diameter overall (still NA 18.1.26)
20" Blockley 650/700 7.28" overall section, 870mm Diameter overall
Blockley 475/500 5.51" overall section, 775mm Diameter overall
Michelin DR 6.50/7.00 7.6" overall section, 866mm Diameter overall
With thanks to Jonathan Bailey Jan '26
Dunlop tyre guide
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Wellbase wheels and tyres were NOT fitted by VM on production 30-98s. Original equipment was either 820x120 (880x120 on some exported cars) or 32x4.5.
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Chassis & subframe cracks
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After 100+ years of hard use, it would be surprising not to find some cracks in a 30-98 frame. Key suspect areas are the front of the subframe, and also the front crossmember under the radiator.
If not attended to promptly, a cracked crankcase flange may be a consequence of the frame failure. |
Watford Speedo Drive
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Kindly supplied by John Kent
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