Hey guys
A number of AM resin manufacturers make what they call burnt or damaged Sherman road wheels w/o rubber tyre. Here is a question:
were those wheels really smooth or should they have some grooves for
better grip of the tyre like T-34 and the likes in German service (Pz.III/Pz.IV)? I can't find neither drawings nor decent resolution images of the thing.
Thanks in advane!

There are a number of surviving Sherman's on display with badly chunked and even bare roadwheels. Look at the Sherman minutae pages and the toadman images? Also the "Tank (second) life" thread here on Armorrama has Sherman chassis used as cranes and logging vehicles that are bare of the rubber.

Thank you Matt and Stephen. I've just found this site:
http://sturgeonshouse.ipbhost.com/topic/266-the-m4-sherman-tank-epic-information-thread-work-in-progress/
A lot of information and pictures to look at...

I believe the earliest M3/M4 wheels were smooth. But certainly the more common construction had groves on the metal wheel to form a solid foundation for the rubber tire. Panzer Art makes fantastic burnt Sherman wheels in resin -- VVS spoked ones, stamped spoke ones and a set of HVSS burned out ones. I know of no other 1/35 that do these with the grooves. I have several sets and have my spoked ones for a burned out tank in Africa --

From what I have found so far Matt in the post above is right: no grooves, just thin raised lip on both sides. Keep looking for HQ images for clarification...

What purpose would the grooves serve?
The engine power is transferred to the tracks by the sprocket wheels, all the others are just rolling along and carry weight or stretch the track (the idler).
What the grooves could possibly do is to provide stress points to the rubber and maybe cause failures when the rubber is pressed against the edge of a groove.
A lip at the edges of the wheel would be enough to prevent the rubber from slipping off.
/ Robin

While I’m not a suspension engineer, the T-34 roadwheels have radial grooves under the tyres. I assume that the purpose is to reduce the risk of the tyres moving laterally. Maybe the overlapping rims on US wheels achieved the same purpose.

Different manufacturing methods ???
/ Robin

Maybe contact armour museums and collectors to see if they have any information

Google sherman tank champagne and mort-homme. They burned out and were put on display and you can see the road wheel with out rubber. Mort-homme even has one mounted to the glacis plate that is bare of rubber and no grooves.

No problem. I'm using my tablet so posting links is a pain in the arse.

And then there's this:



It would not surprise me if it changed over time, with the serrations added to improve adhesion when more synthetic rubber was used in the tire compounds.

KL

Interesting drawing!
Any chance of someone having a copy of the preceding drawing?
It says 'Supersedes old drawing C55291, under revision date of 9.30.42'
The serrations are to be: 'Serrations per mfr's standard'.

Serrations to give the rubber a non-smooth surface could be as small as 1 mm or 0.005 inch and that isn't very visible in photos and even less in 1/35th ...
/ Robin