A method of improving rubber life.
"To Deputy Chief of ABTU, comrade Panfilov
According to your recommendation, tilted wheels will be installed on the production A-7M vehicle. This modification leads to improvements when moving on wheels, as it significantly increases the lifetime of the rubber (see report #061 on field trials of A-7M tanks model 1939, pages 185-191 and 208). When driving on tracks, this modification leads to no changes.
Using tilted wheels will decrease parts commonality and introduce the possibility of confusion when using spare wheels in the field. Please confirm the necessity of using tilted wheels.
Senior Military Representative of ABTU, Military Engineer 2nd grade, Kozyrev."
"To the Chief of the Red Army ABTU, Army Commander 2nd grade, comrade Pavlov
Copy to: factory #183 director comrade Maksarev
Factory #183 notified you with letter #S01271 on March 5th that the replacement of wheels with tilted ones on A-7 and A-7M vehicles is not suggested. In a telegram from April 18th of this year, the factory reports that there was no answer to its letter from ABTU.
GlavSpetsMash asks you to confirm that replacing wheels with tilted ones is not recommended due to the reduction of parts commonality.
I propose to the factory #183 director that he should not make any changes to the production process without prior agreement from GlavSpetsMash.
GlavSpetsMash Chief, Surenyan"
Despite the arguments, handwritten comments on the page order tilted wheels to be put into production. There seems to be no record of this modification actually making it into production, though.