------------------------------------------------------------------------------- ISO / ETRTO [1] England France [2] ------------------------------------------------------------------------------- 36 x 2-1/4 German unicycle 642 28 x 1-3/8 700(A) US/UK utility bikes 635 700B B = 2nd revision of rim size 44-635 28 x 1-5/8 x 1-1/2 old V rim 40-635 28 x 1-1/2 700x38B 634 700B another 700B 32-630 27 x 1-1/4 old UK RB standard 76-622 29 x 3.0 29 US Surly MTB 57-622 29 x 2.5 57-622 29 x 2.20 700x57C C, the only 700 today 55-622 29 x 2.25 Vittoria Barzo, rigid 55-622 29 x 2.2 54-622 29 x 2.25 52-622 29 x 2.1 52/52-622 50-622? 29 x 1.9 700x48C René Herse Orace Ridge. gravel 622 28 x 1-3/4 622 27 x 3/4 47-622 28 x 1.75 x 2 47-622 28 x 1-5/8 x 1-3/4 700x45C 28x1.75 47-622 27 x 1.75 700x45C 42-622 28 x 1-5/8 700x40C 40-622 28 x 1-5/8 x 1-1/2 700x38C 37-622 28 x 1-5/8 x 1-3/8 700x35C 50-75 PSI 37-622 28 x 1-3/8 x 1-5/8 37-622 28 x 15/8 x 13/8 700x35C 32-622 28 x 14/8 x 10/8 32-622 28 x 1-1/4 x 1-3/4 32-622 28 x 1-5/8 x 1-1/4 700x32C 32C dual pivot max [3] 32-622 28 x 1-5/8 x 1-1/2 700x32C 28-622 28 x 1-5/8 x 1-1/8 700x28C 26-622 700x26C Kenda Kontender 23-622 700x23C 700x28C 25-622 700x25C Freedom ThickSlick 23-622 700x23C 20-622 700x20C Kevlar 700x19C 40-609 27 x 1-1/2 Puch Exclusive 27 597 26 x 1-1/4 650 [4] 26-597 26 x 1-3/8 37-590 26 x 1-3/8 650x35A 587 700D D, discontinued in the 80s 26 x 1-3/4 650B standard 26 57-584 27.5 x 2.25 MTB 27.5 56-584 27.5 x 2.20 650x56B 55-584 27.5 x 2.2 27.5 x 2.10 58-584 27.5 x 2.10 650x54B 54-584 26 x 1-1/2 x 2 584 26 x 1-1/2 650B 52-584 27.5 x 2.10 650x52B 48-584 650B R H Juniper Ridge 44-584 26 x 1-1/2 x 1-5/8 44-584 26 x 1-5/8 x 1-1/2 40-584 26 x 1-1/2 650x35B 23-571 650x23C triathlon 571 26 x 1-3/4 TT 571 26 x 1-3/4 650C utility bikes 571 26 x 1 650C 26 x 1.5 x 2 58-559 26 x 2.30 Soda Sharky 60-559 26 x 2.35 57-559 26 x 2.25 56-559 26 x 2.20 55-559 26 x 1.95 54-559 26 x 2.10 559 26 x 2 53-559 26 x 1.95 50-559 26 x 1.95 50-559 26 x 1.9 1.9-2 = [1.9, 2] 50-559 26 x 2.0 50-559 26 x 1.95 47-559 26 x 1.75 40-559 26 x 1.5 ofo rental bike 35-559 26 x 1.35 Schwalbe Kojak slicks 24 x 2 trailer, 2 - 19-3/4 [5] 37-540 24 x 1-3/8 600x35A trailer; rental bike 70-507 25 x 3.00 not a fatbike: < 4.0 54-507 24 x 2.10 50-507 24 x 1.95 50-507 24 x 1.90 1.90/2.0 = [1.9, 2] 47-507 24 x 1.95 47-507 24 x 1.75 58-406 20 x 2.25 folding bike 56-406 20 x 2.10 20 x 2.125 47-406 20 x 1.75 folding bike; fits 20*2.125 rim 44-406 20 x 1.75 40-406 20 x 1.5 35-406 20 x 1.35 Schwalbe Kojak slicks 37-349 16 x 1-3/8 32-349 32-349 16 x 1-1/4 54-305 16 x 2.00 footbike 54-305 16 x 1.95 footbike 47-305 16 x 1.75 4.6 kgf/cm^2 ~= 65 PSI 37-298 14 x 1-3/8 Bickerton folding bike 62-208 12-1/2 x 2-1/4 62-203 12-1/2 x 2-1/4 ------------------------------------------------------------------------------- [1] ISO 5775 = International Organization for Standardization, standard 5775 The table is sorted by the ISO BSD; after that, the tire width; after that, whatever comes next that is bigger from left to right. If you pull the beads flat apart and measure the width from bead to bead, it should be approximately 2.5 times the ISO width. Some plausible sizes are not ISO approved - to write on a tire, at least. E.g., for 622 tires between 40 and 50 mm wide, approved widths are 40, 42, 44, 47, and 50. How to measure the width of an inflated tire, without having to remove it from the bike? Squeeze the tire with a caliper. Then remove the tool and try reinserting it; it won't work. Increase width in steps of 1mm until it goes down. This is the actual tire width. ETRTO = European Tyre and Rim Technical Organization [2] How the ISO systems works: table: https://dataswamp.org/~incal/bike/TIRE figure: https://dataswamp.org/~incal/bike/tire-size.png [3] https://bike.shimano.com/en-EU/product/component/shimano/BR-R451.html [4] Several ISO BSDs are possible for 26" tires: 597 is 650 590 " 650A 584 " 650B, called '27.5' on MTBs, on other bikes '650B' 571 " 650C, on race bikes 559 " on MTBs and FBs, decimal width notation; called '26"' [5] A 19-3/4" rim is ~502 mm so a 507 mm BSD tire won't work. ------------------------------------------------------------------------------- https://dataswamp.org/~incal/bike/TIRE incal@dataswamp.org -------------------------------------------------------------------------------