If you want cheap and narrow for the wheels you have I'd just head to Wilkos, or Decathlon. It's probably the most common size. you probably want 26 x 1.8, but worth checking the width will work though as your frame is likely designed for 700c or 27" rims.
If you want cheap and narrow for the wheels you have I'd just head to Wilkos, or Decathlon. It's probably the most common size. you probably want 26 x 1.8, but worth checking the width will work though as your frame is likely designed for 700c or 27" rims.