Originally Posted by
mstateglfr
Are we talking about an '85 Fuji Allegro?
If so, then probably 32mm(1 1/4) wide is the most if you have the stock 27" wheels. Thats a common 27" size, the only larger size I know of for 27" is this 1 3/8" size
SwiftTire 27? x 1 3/8? Tan Tire ? Made by Panaracer (Plenty Back in Stock) ? SWIFTTIRE.
If you have changed the wheels to 700c, then that gives you more room for tires since 700c is a bit smaller than 27". You could fit a 35mm tire in there most likely. Many of the entry level road bikes from the 70s thru mid-80s had a good bit of tire clearance.
Ideally you want 4-5mm of clearance on all sides of the tire, but depending on where and how you ride, you could get away with less.
Thanks for the reply. It's not the Allegro. I have 27x1-1/4. Pretty happy with them. I want to squeeze bigger tiers onto my State 4130 which has 700cx23 tires on it. I want something meatier on it for bunny hops.