Motorcycle Repair: tyres to rim size, ktm 400, tyre size

Question
Hi Mark, I own a '94 KTM 400 and would like to fit it with wider tyres..i searched the web but couldn't find info on this rim to tyre size thing.

My rims' size are 21' diameter and 1.6' wide (front) & 18' diameter and 2.5' wide (rear). What are widest size tyres I can fit onto each rim, without affecting safety? Thanks very much.

Answer
Hi Tre,

I recommend calling a major parts retailer such as Chapperal or Compettittion Accessories and ask the sales rep same question. They have catalogs with this information and will tell you the sizes available for your MC.

Your MC was designed with specific tire to rim sizes. Going with a wider tire other than specified is a safety hazard. You should get wider rims for wider tires, if available.

Respectfully,
Mark Shively