Motorcycle Rim Band Sizes: Choosing the Right Diameter and Width

A motorcycle rim band must match two things: the rim diameter and the width of the rim bed. The rim diameter is the number after the dash or the R on the tire sidewall, for example the 17 in 120/70-17 or the 18 in 3.00-18. That number tells you which band diameter to buy: a 17-inch rim needs a 17-inch band. The width depends on the rim, not the tire. The band should cover every spoke nipple and the full nipple-hole area of the rim bed without climbing onto the bead seats. Tire width helps only as a clue to how wide the rim is likely to be. Load index, speed rating and overall tire diameter do not change the band size.

What is a motorcycle rim band and when do you need one?

A motorcycle rim band, also called a rim strip or rim tape, is a rubber, plastic or cloth strip that lies in the centre channel of a spoked rim. It sits between the spoke nipples and the inner tube. Its job is to stop the nipple heads, the edges of the nipple holes and any burrs from chafing or puncturing the tube.

Rim bands belong on tube-type (TT) spoked wheels, where the spoke nipples pass through the rim bed into the tire cavity. Cast or forged wheels and sealed tubeless spoked wheels have no exposed nipple holes in the air chamber, so they do not use a conventional rim band.

Which sidewall number gives the rim band diameter?

The last number in a motorcycle tire size is the rim diameter in inches, and it is the only tire figure that directly sets the rim band diameter. The rim diameter is measured at the bead seat, where the tire bead sits, not across the outer edge of the rim flange. A 17-inch tire fits a 17-inch rim, and that rim takes a 17-inch rim band.

Common motorcycle tire size formats show the rim diameter in the same position:

• Metric: 120/70 ZR17 – rim diameter 17 inches.
• Inch: 3.00-18 – rim diameter 18 inches.
• Alpha (letter): MT90-16 – rim diameter 16 inches.

Rim diameter is fixed in whole-inch steps on motorcycle wheels, so a band for a different diameter will not work. A band meant for a 19-inch rim is too long for an 18-inch rim and may bunch or fold. A band meant for an 18-inch rim may not stretch onto a 19-inch rim, or it may be stretched so far that it thins or slides off the nipples. Rubber bands are usually made slightly smaller than the rim so they stretch into place and stay put.

How to read the other tire markings, and which ones matter for the rim band

Most of a motorcycle tire sidewall describes the tire itself, not the rim. The table separates dimensions, ratios, units and performance ratings, and shows whether each one affects rim band choice.

Marking (example)	Type	Meaning in plain language	Relevance to rim band size
120 in 120/70-17	Dimension, millimetres	Nominal section width of the tire, measured across the sidewalls on a specified rim	Indirect: wider tires are mounted on wider rims, which usually have a wider rim bed
70 in 120/70-17	Ratio, percent	Aspect ratio: sidewall height as a percentage of section width	None: it changes tire height, not the rim
17 in 120/70-17	Dimension, inches	Rim diameter at the bead seat	Direct: sets the rim band diameter
3.00 in 3.00-18	Dimension, inches	Nominal section width in inches (about 76 mm). Older inch sizes have no printed aspect ratio	Indirect, like metric width
MT90 in MT90-16	Letter code	Alpha width code (M = motorcycle, T = a width class) with a 90 percent aspect ratio	Indirect only
R or ZR, or a dash	Construction code	R means radial. ZR is an older high-speed radial marking. A dash usually means bias-ply	None
58 in 58W	Performance rating	Load index: a code for the maximum load per tire, read from a load index table	None
W in 58W	Performance rating	Speed rating: a letter code for the maximum rated speed	None
TT or TL	Construction type	TT = tube type, TL = tubeless	Relevant: rim bands are used where a tube is fitted in a spoked rim
4PR, REINF	Strength rating	Ply rating or reinforced construction	None

How do width, aspect ratio and rim diameter change tire size?

Sidewall height equals section width multiplied by aspect ratio. Overall diameter equals rim diameter plus two sidewall heights. Circumference equals overall diameter multiplied by pi (about 3.1416). These are calculated, nominal figures for comparing tire sizes. They are not measurements of a particular tire.

Simple calculation method

1. Convert rim diameter to millimetres: rim diameter in inches × 25.4.
2. Find sidewall height: section width in mm × (aspect ratio ÷ 100).
3. Find overall diameter: rim diameter in mm + (2 × sidewall height).
4. Find circumference: overall diameter × 3.1416.

Example for a 120/70-17 tire: the rim is 17 × 25.4 = 431.8 mm. The sidewall is 120 × 0.70 = 84 mm. The overall diameter is 431.8 + 168 = 599.8 mm, and the circumference is about 1,884 mm.

Worked comparison of common motorcycle sizes

Tire size	Rim diameter (mm)	Sidewall height (mm)	Overall diameter (mm)	Circumference (mm)	Rim band diameter
120/70-17	431.8	84	599.8	about 1,884	17 inch
130/70-17	431.8	91	613.8	about 1,928	17 inch
180/55-17	431.8	99	629.8	about 1,979	17 inch
3.00-18 (nominal, about 100% profile assumed)	457.2	about 76	about 610	about 1,915	18 inch
110/80-19	482.6	88	658.6	about 2,069	19 inch
90/90-21	533.4	81	695.4	about 2,185	21 inch

The three 17-inch tires differ by about 30 mm in overall diameter, but all of them use a 17-inch rim band. The 3.00-18 tire is close to the 17-inch sizes in overall diameter, yet it needs an 18-inch band. Overall tire diameter and circumference tell you about gearing, speedometer reading and clearance. They do not tell you the rim band size.

Calculated geometry versus real dimensions and fitment

The calculated figures are nominal. Actual tire width and height vary by manufacturer, tire model and construction, and with the rim width the tire is mounted on. A wider rim spreads the sidewalls and generally makes the tire slightly wider. Inflation pressure and load also change the dimensions. Inch-sized tires do not print an aspect ratio, so the 100 percent profile used above is an approximation only. Whether a different tire size fits a motorcycle depends on the approved rim widths, frame and swingarm clearance, and the vehicle manufacturer's specifications. Geometry alone cannot confirm it.

How do you choose the right rim band width?

The correct motorcycle rim band width covers all spoke nipple heads and the full area around the nipple holes in the rim bed, while staying inside the centre channel and off the bead seats. If a band is too narrow, nipple edges are left exposed and can chafe the tube. If it is too wide, it may crease or ride up under the tire bead. That can make the bead seat poorly, and the folded edge itself can damage the tube.

Why the rim width marking is not the band width

Motorcycle rims are often marked with a width and a diameter, such as 2.15 × 18 or MT2.15×18. The 2.15 is the nominal width in inches between the rim flanges, about 54.6 mm. MT and WM are rim profile designations. The rim band does not span that full width. It sits in the narrower drop centre or rim bed, where the nipple holes are. The flange-to-flange rim width is therefore only a starting point, and the band should be narrower than that figure.

Steps to measure and select a rim band

1. Read the rim diameter from the tire sidewall or the rim stamping, and choose a band of the same diameter in inches.
2. Remove the tire and tube, and inspect the rim bed with the old band removed.
3. Measure in millimetres across the area the band must protect. This is the width occupied by the spoke nipple heads and holes, including any offset rows of holes on rims where the spokes alternate from side to side.
4. Measure the width of the flat or curved bed between the points where it starts to rise toward the bead seats.
5. Choose a band wide enough to cover the nipple area with some overlap on each side, but no wider than the rim bed.
6. Check whether the band needs a valve hole of the right diameter, and for off-road wheels, extra holes or clearance for rim locks.
7. Fit the band so the valve hole lines up with the rim's valve hole, then confirm it lies flat and centred all the way round with every nipple covered.

When bands are labelled by tire size instead of millimetres

Some rim bands are sold by a tire size range, such as a band for 2.50 to 3.00 × 17 tires or for a range of metric widths on a 17-inch rim, rather than by a width in millimetres. In that case, the diameter must still match exactly. The width range is the maker's estimate of the rim widths those tires normally use. If your rim is wider or narrower than usual for the tire fitted, measure the rim bed and compare it with the band's actual width before you buy.

Valve hole and rim lock considerations

The valve hole in a rim band must line up with the rim's valve hole and suit the tube valve stem. If the hole is missing, too small or out of position, the valve stem can sit at an angle or rub against the band edge. Some bands come without a hole, or with a hole only for a standard valve, so check this against your rim. On rims fitted with rim locks, the band needs openings or must be cut to clear the rim lock bolt, so that the lock clamps the tire bead rather than the band.

Summary: matching a rim band to a motorcycle wheel

• Diameter: use the rim diameter from the tire size (the last number, in inches). It must match exactly.
• Width: measure the rim bed and the nipple-hole area in millimetres. Cover every nipple without reaching the bead seats.
• Ignore for band sizing: aspect ratio, load index, speed rating, ply rating and overall tire diameter.
• Use tire width carefully: it hints at rim width, but the rim itself is the reliable reference.
• Calculated tire dimensions are for comparing tire sizes. They do not confirm vehicle fitment or band size.