Yes..If you want authenticity the 325s are the ones to go for...Also, the narrower front tyre is better if you want to venture off road...
Many fit 350s both ends...Personally I think the 350 is visually better on the front as it fills the wide M20 mudguard more but as noted it isn't the 'correct' size...Ian
We always use 3.50 19 K70 Dunlops in front and Trials universal 3.50 19 as rearwheel. The Trials universal is good on all terrain and lasts very long for a Off road tire... more than 6000km
I Had fitted a 4.00.19 once and it was exactly the same measures then a 3.50
https://www.jareksgarage.de/bsa-m20?lightbox=i111w9s
I've got newly fitted Ensigns on standard Dunlop WM2 rims and measure 21cm from flange to flange. A caliper across the width measures exactly 3.25" so I think the sizing is fairly accurate.
They do look skinny under big mudguards, but that was the 1930s fashion.
If you're not rebuilding in military trim and want a period civilian look with no off-road riding then a K70 with a ribbed front would give good results.
Thanks Rik! so a little smaller than the 'old' 3.25's I measured at 22 cm. Think it might be acceptable for a WM2 rim but think it would be too small for my liking on the wide WM-3 M20 rims.
I guess the 3.50 Ensign Universal would be around 23 cm then? , anyone here who has them fitted?
Michiel, I have no experience of WM3 rims on singles...My Commando only has a WM2 on the front.:relaxed:
I've jsut measured on of the 1939 dated Good-Years that were on the 16H, from rim mark to rim mark. It measures 21cm too...I don't know if they were narrower than the Dunlop fitments, but it's marked "Balloon"
They were fitted to quite a number of Nortons from 1939 onwards and I think most early WD Enfields. Firestone seem to have been the more common alternative fitment for BSA but they do seem to have monopolised on Dunlops.