I'm installing a set of Shinko 230 Tourmaster tires on stock BA spoked rims. A 170/80 on the rear and a 120/90 for the front. My old tube for a 110/90 said the largest size tire for that tube was a 110/90. Sooo, I looked in the tech vault post on Ty's tire post and tube link. The tube link said a 4.00-4.50-18 tube (which I bought and installed) for a 120/90 tire, but I was wondering if such a large tube would be necessary (or would fit) with the relatively narrow BA spoked rim. After installing, I have a bulge of sorts making the tire wobble when turned by hand. I will investigate to see if the tube is folded inside the tire, but I would like to know what size tube BA.com folks used with their 120/90s. Thanks,
