Finding the right tires for your vintage HONDA CB550 is easy. But like all endeavors, this one, too, requires some advance knowledge. Simply going to websites like JP Cycles’ and searching for tires to fit your 1977 HONDA CB550K is… an exercise in futility. Because that search will advise you that a rear tire that will fit your vintage HONDA CB550 motorcycle is an AVON AV72 Cobra 300/35 R18 – a tire that is almost 12” wide, slightly wider that the rear tires on a 2015 BMW M5, and which will never fit your original rim, and which is more than 6 inches wider that the widest rear tire your HONDA CB550’s swing arm will allow. Not good.
So, what do we need to know? A lot. A hell of a lot indeed, if we are to get the right tires.
Here are a few guiding principles to selecting the correct tires for your vintage machine as I see them (with the disclaimer, of course, that this is neither a comprehensive study nor a fitment guarantee):
- TIRE DIAMETER: Most vintage motorcycles were designed so the front and rear tires were of equal height (diameter), meaning that if you measured the height of the front and rear tires (mounted, properly inflated and with the bike off the center stand) from the ground to the top of the tire, your measurements would show an equal or very similar number. It is on this principle of equal tire height that your bike’s suspension was designed. Just for the sake of it, imagine the rear tire is infinitely small and the front tire is infinitely large. The motorcycle will sit vertically, with all the weight on the rear wheel and no weight on the front wheel. That’s not good, is it? Among other things, this kind of design will require a suspension very different from the one you have. So, knowing the tires’ diameter is pretty important. Because you want to choose tires (front and rear) that have an equal or similar diameter. And you want to make sure that diameter is not much larger than your original tires’ diameter or else the front tire may rub against the front fender.
- TIRE WIDTH: Most vintage motorcycles were designed to have narrow tires, hence their relatively narrow rims of 1.85 to 2.15 inches in width (that is the width of the rim from inner wall to inner wall). Using very wide tires on your vintage machine may look cool, but will impact handling and performance. For example, a tire that is much wider than standard will have a much larger surface area that is in contact with the road. A much larger surface area in contact with the road will result in greater resistance. A greater resistance means slower acceleration, slower speed, less handling agility, greater relative fuel consumption and a shorter stopping distance. More practically, the width of the front tire is dictated by the distance between the front fender’s mounting bracket (that distance for a HONDA CB550 is approximately 4-3/8” or 111 mm) and the width of the rear tire is dictated by the distance between the two arms of the swing arm at roughly the point where the tire will be (that distance for a HONDA CB550 is roughly 5.5” or 140 mm). In very approximate terms, this means that a front tire with a width of, or greater than, 110 mm and any rear tire with a width of, or greater than, 130 mm should be considered with caution and used only after very careful measurements have been taken. Many riders have reported that wider than OEM tires usually show uneven wear pattern and do not last as long.
- TIRE TYPE: Radial tires are designed exclusively as tubeless type tires and so are unsuitable for vintage bikes, which by nature of the fact that they all have spoked wheels must use inner tubes. Obviously, in a case where the bike has been customized to use cast alloy rims this rule may not apply. Bias ply type tires are the most common choice. Some of them are designated exclusively as TL (tubeless), some are designated as both TL and TT (TT = tube type) and others are designated exclusively as TT. The last ones are usually softer in handling for installing (not riding) purposes and are the easiest to install using tire irons only.
- RIMS SIZE: Most vintage bikes used a 19-inch rim on the front and an 18-inch rim in the rear. For those who are planning on replacing their original rims, non-OEM size rims are available in 18-, 19- and 21-inch size. It is, hypothetically, of course, possible to use any combination of 18” rims, 19” rims and 21” rims. For example, a 21” rim on the front and an 18” or 19” or even a 21” in the back. Or any other conceivable combination in between. The limiting factor is that 21” rims are only offered in narrow width of 1.60, 1.85 and 2.15 inches. Another limiting factor if using 21” rims for the front and rear is that literally all tires offered by any and all manufacturers in 21” size are always front tires intended to be used only on the front wheel. That is to say that such tires have a weight rating that may make them unsuitable for use in the rear and, more importantly, they are “directional” tires meaning that they have been designed to be used only in a specific rotational direction. More on this in the following topic.
- DIRECTIONAL VS UNIVERSAL: Directional tires are designed as such mostly because their ability to displace water, dust or dirt is greatly enhanced in a specific direction of rotation. However, the general rule of motorcycle DIRECTIONAL tire design when it comes to using a front directional tire on the rear rim and vice versa is this: Front tires are designed in such a way that they grip/handle best during breaking (deceleration) and rear tires are designed so they handle best during acceleration. Makes perfect sense, doesn’t it? The front tire does most of the braking and the rear tire does all of the driving. Water/dirt displacement and grip/load handling are precisely why such tires have arrows embossed in the side wall telling you which way they should be installed. The so-called UNIVERSAL tires have no designation for front or rear and no directional arrows in the side wall. Many people seem to advise that a DIRECTIONAL front tire can be used in the rear for as long as it is installed in the opposite way, i.e. the arrow on the side wall points away from the direction of rotation. This seems to make some logical sense. Since a front tire is designed to grip in deceleration, it is assumed that if it is installed in the opposite direction it will grip on acceleration. What is this all about? Well, the trouble is that nobody makes a 21” tire that is specifically designated as a rear tire. So if you wanted to use a 21” rim on the front and a 21” rim in the back, your only option is to use 21” front tires and reverse the one in the rear. Similar approach applies to using a 21” rim on the front and a 19” rim in the rear because the choice of 19” tires designated as rear tires by the manufacturer is very limited indeed, but many 19” front tires are available that could be used on the rear rim if, and only if, the logic above really applies. And of that only speculations exist however logical they may be.
- OTHER CONSIDERATIONS: In case all of the above isn’t confusing enough, there is more to consider. That is why I said, “There is a hell of a lot we must know in order to choose the right tire.” Tire size nomenclature, tire weight rating, tire speed rating, intended use (street, track or off road) date of manufacture, etc. Plenty of information exists on how to interpret tire nomenclature, (i.e., what does 110/90-R19H mean and what does 4.00-19 mean?), and so I am not going to cover it here. An excellent tutorial by tire manufacturer AVON, which answers all questions about sizes and other markings, and provides much additional information is available on their website. Here is the link to it: TIRES 101.
- Take a look at your rims and note the stamped size. It will be something like 19 x 1.85 or 18 x 2.15. If there is no stamped size on the rims, throw them away. They are not original. If the rear rim’s size is 18 x 1.85, you may want to consider replacing it with an 18 x 2.15 or 18 x 2.50 or 18 x 2.75 rim. Because other than AVON, nobody else makes an 18” diameter rear tire that will fit as narrow a rim as 1.85.
- Choose tires that will fit your rims and that you like the look of.
- Ensure the front and rear tires you have chosen are the same or similar (+/- 0.25″) diameter.
- Ensure the tires’ width is going to be OK and, in particular, that the front tire is not going to rub against your bike’s front fender’s mounting bracket.
- Note that tires designated as tubeless (TL) are more difficult to mount using tire irons than tires designated as tube type (TT).
- Note the tires’ weight and speed rating, and all other information such as are they directional or universal, etc.
- Keep in mind that many motorcycle tire sellers do not provide all necessary information and, in some cases, provide incorrect, irrelevant and/or misleading information.
Click on the button below for a list of tires that may fit your HONDA CB550 or another vintage machine equipped with similar rims.
You can use the links below for additional information, tires’ specifications, and some other tire manufacturers not listed in the “Tire Guide” above: