[Lance]

Originally Posted by bigred5765

sorry not true at all, all schumacher tires fit on the slim rims, we use slim rims quiet alot on mini pins and mini spikes

I think you misunderstood my comment - maybe "can only use" has confused you. Whilst technically "all Schumacher tires (sic) fit on slim rims" then I am sure you have found that medium "front" tyres are wider than the rim and are therefore unsuitable to use.
All the Schumacher "slim" tyres i.e. U6759/U6609/U6592/U6581/U6550 and U6549 are designed to fit on the slim rims (I know some people who do not have slim rims sometimes fit the slim tyres onto medium rims but they only fit on 2/3rds of the rim width[not ideal, but keeps them racing]. As a Schumacher driver you will know that with 2WD if you "STRETCH" a slim tyre to fit the entire width of a medium rim then this deforms the "contact area" of the tyre surface causing a "U" shape resulting in the tyre shoulders only having contact with the track and very poor grip levels. Equally if you try to fit the normal front tyres designed for the medium rim i.e. T562/T693/U6515/U6517/U6557/U6595/U6601 and U6607 onto a slim rim then you will have the problem of the tyre being wider than the rim. I hope this clarifies your misunderstanding.