tires and tubes

What are tire and tube sizes for 77 650 C? Front and rear.

I've been using Pirelli Sport Demons on my 1977 KZ650-C1 for 5+ years and really like them. They stick well and don't wear out too quickly. I use 100/90-V-19 up front and 120/90-V-18 on the rear. Be sure to install new tubes made for the same size tires. The tubes will have the tire sizes on them - be sure they match the tire sizes. Based on the recommendation from Pirelli I use Metzeler tubes. The front tube is Metzeler ME-E19 M/C; the rear tube is Metzeler ME-F18 M/C. Denniskirk.com or ronayers.com usually have decent pricing. Ed

You can use the tires as Ed mentioned, the front is near perfect, but the rear will be wider than the stock tire. Stock size is 3.25-19 on the front and 4.00-18 on the rear. I'm a firm believer in the 4.00-18 as being the right tire in both looks and function, but if you want wider which most do, the 120/90-18 is the way to go. Front 3.25-19 or 100/90-19 I doubt either could be identified as much different in looks or function. Don't use the gay 110/90 size that is supposedly the modern equivalent of the 4.00-18 for sure on the rear as it is gay looking in looks.

My current is a 130/90-18. Which I have found. I dont know if it's a width thing on 130 part of it but I like a wider tire. Am I right about 130 being wider than 120?? My main concern was the tube. Still having trouble finding that one.

The 130 tire is a bit wider than the 120 tire. In the past, for years I ran 130/90-18 tires on the rear. I now run 120/90-18 on the rear. Here's why - the 130 tire is designed to be mounted on a rim that is a good bit wider than the stock KZ650-C1 rim. It an be squeezed onto the stock rim, but in doing so the cross-section of the tire is distorted and as a result there is no more tread on the ground than with a 120 tire. Plus shape of the tread of the 130 tire is distorted. In the end, the 120 tire works just as well or better than the 130 tire and is much easier to mount. Ed

Ah Ha! Ok. Am I certain that my rim is stock? I don't know. Like the look of the 130 but will get the 120 if i will have better performance and life.

Can I get a link for a tube for the 120?

RonKZ650 wrote: You can use the tires as Ed mentioned, the front is near perfect, but the rear will be wider than the stock tire. Stock size is 3.25-19 on the front and 4.00-18 on the rear. I'm a firm believer in the 4.00-18 as being the right tire in both looks and function, but if you want wider which most do, the 120/90-18 is the way to go. Front 3.25-19 or 100/90-19 I doubt either could be identified as much different in looks or function. Don't use the gay 110/90 size that is supposedly the modern equivalent of the 4.00-18 for sure on the rear as it is gay looking in looks.

I don't know how gay it is, but running the 110-90-18 in place of the 4.00-18 means the metric is a shade smaller. Seems to lower the gearing a bit on mine, but it looks and runs OK. The 120-90-18 is a shade large which is OK but probably means it will wear the center patch faster because the rim is a shade narrow for the tire.

The 120 tire wears very uniformly and lasts as long or longer than the narrower tire. I've been using that size for quite a few years and find that it works very well. It's width is so close to that of the original tire that the profile isn't distorted.

One other thing to consider is that despite what tire charts show, different model tires labeled with the same size can have very different widths. This is even true when they are from the same manufacturer. It shouldn't be the case, but it is, and sometimes the widths vary by a whole lot. Below is an example of what I mean. Both tires are manufactured by Michelin. Both tires are size 100/90-19. And yet, one tire is at least 1/2" wider than the other. The tires are shown unmounted, but I can assure you that the difference was still just as obvious when they were mounted on the rims. This may also explain why some tires are easier to mount than others. The inner diameters may also vary somewhat between tire models. The lesson I learned from that is that the tire sizes are approximate at best and it pays to physically compare tires when buying. Ed

650ed wrote: One other thing to consider is that despite what tire charts show, different model tires labeled with the same size can have very different widths. This is even true when they are from the same manufacturer.

The diameters are different as well you can see that in the picture. Funny how much variation in tires that are supposedly the same size.

Yup. I'm glad they're making tires and not handgun or rifle ammunition! :woohoo: Ed