strange wheel size?



danp100

New Member
Feb 12, 2012
1
0
0
Hi,
i recently needed a new rear wheel so i took my bike to halfords and they ordered me one, telling me it would be similar to what i already had. Today i have transferred the rear cassette to the new wheel etc, and now i notice the size is slightly odd. It is 622 x 13c. I am not sure that i can use the same tyre and inner tube with this size wheel? my tyre is 700x 23c.
Have halfords given me the correct wheel and if not do i now need a new tyre and inner tube? thanks for the advice,
dan
 

oldbobcat

Well-Known Member
Aug 31, 2003
3,233
194
48
70
622 mm is the effective rim diameter of a 700c wheel. I don't know what the 13c refers to, but if the tire fits, I wouldn't worry about it.
 

alfeng

Well-Known Member
Jul 23, 2005
6,723
254
63
I'm not sure about the 'c' suffix as described, but half of my rims are 622x13 ...

On those rims, the '13' is the bead-to-bead distance ([COLOR= #808080]i.e., the distance between the hooks which hold the beads on the clincher rims[/COLOR]).

The 622x13 rim was-and-is popular with people who used both clincher & tubular rims because the width of the rim as measured across the brake surfaces is the same AND that means that adjustments do not need to be made to the brake calipers when swapping between the two types of rims.

AFAIK, the MAVIC, SHIMANO, & CAMPAGNOLO wheels ([COLOR= #808080]and, undoubtedly many others[/COLOR]) which are available with tubular rims have clincher rims which are 622x13, too.

You CAN definitely use a 700x23 tyre with a 622x13 rim.
 

jalind

New Member
Nov 12, 2015
1
0
0
oldbobcat said:
622 mm is the effective rim diameter of a 700c wheel. I don't know what the 13c refers to, but if the tire fits, I wouldn't worry about it.
I'm responding to this as the terminology and description are incorrect. The 622mm is a rim dimension, but it's not the Effective Rim Diameter, or ERD. The ERD is the rim diameter measured at the nipple seats inside the spoke holes, plus the thickness of the two nipple heads. The ERD is used, along with hub width and flange spoke hole diameter for calculating the correct spoke length. Each rim will have its own ERD, the deeper the rim, the smaller the ERD, and the shallower the rim, the larger the ERD.

The 622mm is the Bead Seat Diameter (BSD), which is a little below the hook inside a clincher rim, typically down along the rim wall where the edge of the rim tape is located. It's also the nominal inside diameter of the tires made for the rim (which is why they're marked xx-622). The other dimension with it, as someone else already stated, is the width between the hooks inside the rim. Most racing and sport bike rims are marked 622x15 (the kind of bikes that come stock with drop bars) and come stock with 23-622 tires. Tourers usually have wider, beefier 622x17,18, or 19 rims with more spokes in a 3x lacing, and wider 32-622 to 37-622 tires (resembling tandem wheels) as they're made for the additional weight of loaded touring which can be as much as the rider, and rougher roads including occasional gravel and dirt (Trek 520 comes stock with 622x18 rims and 32-622 tires; Surly Long Haul Trucker has 622x19 rims and 37-622 tires).

The 622x13 marking on the rim is its required ISO 5775 (formerly ETRTO) dimensions. Things got so out of hand during the 1970's and 1980's with tire and rim manufacturers fudging dimension numbers to make claims of lighter tires and rims having allegedly the same dimensions, that the European Tire and Rim Technical Organsation (ETRTO) was set up defining very specific methods for measuring tires and rims, and defining which size tires are allowed safely on which size rims. The ETRTO became the ISO 5775 international standard for clincher tires, and hook/crochet and straight wall rims (old and rare now, but also made for beaded tires). Tire and rim makers for road bike clinchers still use the old French size numbers and markings and that's what is often advertised, but both tires and rims are marked with the ISO 5775 dimensions and those are what should be used to determine compatibility between a specific rim and a specific tire dimensionally.

The OP rims were marked 622x13, which is narrower than the stock rims normally found on a road racing or sport bike. A 23-622 tire can certainly be used on it safely. The table in the current ISO 5775-1:2014 shows that a tire as narrow as a 16-622 or as wide as a 25-622 can be safely used in a 622x13 rim.

As a matter of note, the narrowest tire that can be safely mounted on the much more common 622x15 rims is a 23-622, and its widest is a 32-622. That's no guarantee that a 32-622 mounted on said rim will fit between the road bike's front forks and rear chainstays, or that it can even be put on the bike between its brake calipers. Putting on a tire narrower than shown in the table runs the risk of the beads blowing off of the hooks, especially under higher pressure and during cornering. A tire rolling off a rim in a hard turn isn't a pretty sight; guaranteed crash. It also produces a higher incidence of pinch flats and rim damage if you hit a pothole or similar road hazard. Putting a tire wider than shown in the table runs the risk of sloppy handling with too much sidewall flex and with too much outward lateral stress on the rim walls, especially as the rim walls wear down from brake use (I've seen rim walls near failure with stress fractures). In 2006, ISO 5775 was revised to allow some wider tire sizes for the wider rims. See the table in the Wikipedia entry for ISO 5775 that shows allowable tire sizes for each rim size:
https://en.wikipedia.org/wiki/ISO_5775

A crochet-type rim is a hook or clincher rim. A straight side rim is also made for beaded tires, but it's a very old style rim and rather rare now except on old vintage bikes with old, vintage wheels. As tire pressures increased, rims evolved with hooks to hold the bead in place.

John