milesofsmiles

Hello,
I have a Schwinn Voyageur 2 comfort bike with street/slick tires. I want to get some knobby mountain bike style tires, like the Kenda K831 Tire - 26 x 1.95 - REI.com or the Forté Greenway-K Mountain Bike Tire. My current tires say 700x 38C, so I'm wondering if a 700x40 will fit on these rims?

vatdim

Your Schwinn seems to have 700c wheels (700c is a measure of diameter). In this case you cannot use the 26-inch Kenda tires you have linked to, because they have a different diameter.

Whether you can use the 700x40 (where 40 is a measure of width) Forté Greenway-K tires, will depend on your rims' width (I do believe there won't be a problem). In order for this all to start to make more sense, I highly recommend reading up on Sheldon Brown's detailed guide.

energyandair

700 is the rim size in mm where the tire seats into the rim so 700x40 will fit on the rim if if 700x38 does

38 and 40 are the tire cross sectionsin mm. If you have more than 2mm clearance to frame and forks with the 38s, I'd expect the 40 to be fine.

26" (the Kenda) is from a different measurement system based on the approximate outside diameter of the tire in inches. It is a not a very good system for determining what tire will fit on what rim as there can be more than one rim size for a given outside diameter. A 26" tire however typically fits a 559mm rim.

milesofsmiles

Thanks for the info. Yes, I realized that the rim size would be be a big factor. This is exactly what it says on my tire and made it confusing...40-622 (700 x 38C) 28 x 1 5/8 x 1 1/2.

Steve B.

Rim size is less a factor then you'd think. If you are running 38's now, a 40 will more then likely stay on the rim. It's only when you get into really narrow rims designed for road racing bikes do you sometimes run into issues. And even then, lots of mt. bike light weight racing rims were the width of road rims and running 50mm+ width tires.

The biggest issues you encounter when sizing up is clearance under the fork and at the chainstays, with chainstays typically being the usual limiting factor.

As well, tire manufacturers lie about the tire sizes, so sometimes the only way to know is to buy the tires and try them.

milesofsmiles

Yes, that's what I figure. I think I'll do that next weekend. I just can't stay off those trails.

JanMM

622, 700 and 28 are three different ways to describe the same size rim. Tire nomenclature is extremely confusing. Agree you should look at the Sheldon Brown info about tire sizing.
The Forte Greenway tires are available in 26 (also known as 559) and 700 sizes. The 700 x 40 should work for you if you want to ride off-road. Keep in mind that 40 mm is relatively narrow compared to traditional mountain bike sizing.

milesofsmiles

I started looking at the Sheldon Brown info about tire sizing and it helped some, I have to look at it again now that the whole thing is getting clearer.



I noticed that when I was at the store where I bought the bike and there was another one setting there. Those tires looked so wimpy next to the mountain bikes. Oh well, it's the grip I'm looking for, I'll take what ever extra grip the new tires will give me. They won't feel as smooth on the road either I don't think, it's a trade-off between the two surfaces.

milesofsmiles

Well, I got the new tires today, the Forté Greenway-K Mountain Bike Tire, 700 x 40. I like them. I feel safer on non-paved surfaces. I didn't have time to give them a real workout, I'll do that this weekend.

Wilfred Laurier

Sorry to be pedantic, but the 700 is not a measurement of the rim - it is the nominal diameter in millimeters of the wheel with a wide (~38 mm) tire installed, similar to how the 26" is the nominal diameter of a mtb wheel with a ~2" tire installed. The bead set diameter of the '700' rim is actually 622mm.

milesofsmiles

Well, I did it. I traded in the Schwinn (which I will miss) for a GT Backwoods Sport, GT Backwoods Sport Mountain Bike - 2015 Performance Exclusive. It is a 29" mountain bike. I had no intention of getting a new bike today but you know how that goes. I took it on the trails a bit today and really like it.