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Tire Sizes

Poetic jargon allows the well-versed to code-speak among themselves while deflecting prying comprehension of the uninitiated. Wheel and tire formats are prime examples. Just as with a "two by four" having no actual 2 or 4 inch dimension - 29 inches will not be found on a 29er tire. Tires are labeled prominently in poetic/nominal gibberish but often have the actual size embossed elsewhere, along with other pertinent information such as pressure range. 

Tires are mostly rubber - rims are not (rim+spokes+hub=wheel). The structural interface between a tire and rim must be observed. Shape and dimension of tires result from a  multilayered fabric carcass with the all-important bead molded into the edge where it connects to the rim. Rims will have a corresponding bead or other shape allowing a properly sized tire to be installed. This dimension is the bead seat diameter (BSD) and is crucial to discovering what tires will fit on your wheels. Beware that while a substantially larger tire may fit on your wheels, this does not necessarily mean that tire will fit in your frame! Size is limited by frame clearance. For example, the most common road wheel size, 700C, has exactly the same BSD as that on 29er mountain bikes. 

Tubes 

An inner tube is essentially a balloon with equivalent structural integrity. Dimensions are not at all as critical as with tires. Difficulties arise trying to stuff a larger tube into a smaller tire. Whereas a smaller tube will often easily expand to accommodate a larger tire. 

Tubular/Sew-up

The clincher format, described above, is by far the most common tire type available. Most professional race bikes still use tubulars (or sew-up). This format has no bead but retains the inner tube sewn into the tire carcass. Flat repairs are made by removing stitches, patching the tube, then sewing the thing back together - hence "sew-up". The tire is held onto the simple concave shaped rim with glue. Compared to performance capacities of modern tubeless clinchers, the continuing appeal of this antiquated aromatic format is due to, that's right - poetic jargon.

  

Actual (BSD)mm

Nominal/Poetic

Application

137

8 x 1-1/4

casters -wheelchair

152

10 x 2

casters -wheelchair

203

12-1/2 x All

juvenile, scooters, etc.

305

16 x 1.75 - 2.125 - etc.

juvenile, recumbent, trailers,  folding bikes ...

317

16 x 1-3/4

antique Schwinn & tubular

335

16 x 1-3/8

Polish Juvenile

337

16 x 1-3/8

???  rare HTNK

340

400A

European juvenile

349

16 x 1-3/8

folders; recumbents; juvenile

355

18 x 1.5 - 2.125

Birdy folders

369

17 X 1-1/4; 18"tubular

Alex Moulton AM Series special race tubular

390

450A

Euro juvenile

400

18 x 1 -  1-3/8

wheelchair

406

20 x 1.25 - 2.125

BMX, folders,  trailers, recumbents

419

20 x 1-3/4 - 20" tubular

specialty racing - recumbent; Schwinn juvenile

440

500A

Euro juvenile;  folders

451

20 x 1-1/8; 1-1/4; 1-3/8

BMX racing;  recumbents;  folders

457

22 x 1.75 - 2.125

Schwinn - vintage

470

550C;  22 x 1- 1/4

22" tubular; Euro juvenile racing

490

550A;  22 x 1-3/8

folders; Euro juvenile 

501

22 x 1-3/8

wheelchair

507

24 x 1.5 - 2.125

juvenile ATBs;  BMX; cruisers

520

24 x 1; 1-1/8; tubular

HP (smaller riders); Terry; aero time-trial

540

24 x 1-1/8; 1-3/8  (E-5)

wheelchairs; British juvenile;  Saavedra tubular -25"

541

600A

French juvenile

547

24 x 1-1/4; 1-3/8  (S-5)

Schwinn & British juvenile

559

26 x 1.0 - 2.125 & fatter

most ATBs, cruiser, paperboy, fat bikes

571

650C; 26 x 1 & tubular

triathlon; time-trial; Schwinn cruisers

583

700D

short-lived GT format;  often incorrectly "587" BSD label

584

650B; 27.5; 26" tubular

former French touring & tandem format; modern ATB

587

26" tubular (Mavic)

vintage Mavic toobie

590

650A; 26 x 1-3/8 (E.A.3)

3-speeds (not Schwinn); juvenile derailleur bikes

597

650; 26 x 1-1/4(EA.1); 26 x 1-3/8(S-6)

British & Schwinn"lightweights" & "Club"; 3-speed

599

26 x 1.25 - 1.375

vintage U.S.  paperboy

609

27 x 1-1/2

rare Danish format

622

700C; 29er;  28 x 1-5/8 (Euro) 

28 x 1-1/2 (Canada)

most common:  road, gravel, touring, hybrid;
ATBs & some fatbikes; F.13 Canada

630

27 x 1-1/8; 1-1/4; 1-3/8 etc

vintage road bikes- esp U.S.

635

700B; 28 x 1-1/2; F10; F25

British, Dutch, Indian and Chinese rod-brake format

686

32 inch

unicycles

787

36 inch

Tire & Tube Repair

We recommend having a few products at home to help you repair your tires and tubes. We have an excellent selection of essential tools, work stands, and parts. Shop online and pickup your items for free on your next shop visit.