Bicycle Mechanics - Help Understanding what fits - MTB tires 26''

Hey guys,

I have been reading a bit about the different tire sizes but that only left me with more doubts. So I guess I'll just put my question very simply:

"Width wise, what tires fit what wheels?"

Basically I have a cheap MTB fit with 26x2.10 (front) and 26x1.90 (back) tires. I wanted to replace them with road tires. I guess that it's easy to go to a shop and order tires that are that fat and slick but I really wanted to find out how far can I stretch my options... Will 26x1.75 fit these same wheels? Is there a rule like a 2.10 tire will fit a wheel of 2.0 +- 0.20?

Thanks in advance

As long as it is 26 X (some decimal), it will work. If you try try 26X (some fractional) it won't. For example you can probably go down to a 26X 1.5 and be good. (dont try a 26 X 1 3/8, it wont work) They do make a 26X1 which is basically a true road tire (like a road bike), but many of the inexpensive bikes have rims that are too wide to accomodate them. I would recomend a slick 26 X 1.5

Thank you for your prompt reply @Flanderflop ! this will surely give me a lot more options!

I now only need to find some really inexpensive tires in the hague :p - everyone here seems to prefer the 29'' wheels so 26 are more expensive and the LBS around told me that I would need the exact same size as my current offroad ones which led me to believe that I would not feel the ride speed increase if I would get an insainly large (2.10) road tire.

Try to keep tires wider than rims. 26x1.75 is well within reason.

Check your current tires for the number 559. That is the bead seat diameter for common mountain bike wheels in the 26 inch size. Make sure your new tire specifies the same number as your current tire.

JonathanGennick how does the bead seat diameter varies with the width of the tire? IE can I have a 2.20 tire with the same 559 number as a 1.75?

First, figure out your rim width. Look at any brand/part number/26x? on the metal rim itself and do some research.

The LBS needs to clarify their statement about the exact same size. Yes, you need the exact same 559 diameter...No, you don't need the same size width.

If your rim (inside wall to inside wall) is approximately 20mm then you can safely run a 1.5 tire.

Thanks guys !

I just put some 26 x 1.5 Panaracer Pasela's on my MTB. The guy at the shop suggested I don't go any narrower than that.

I just put some 26 x 1.5 Panaracer Pasela's on my MTB. The guy at the shop suggested I don't go any narrower than that.
And what are your wheel specs?

Not totally sure, but I can measure them this evening. Inexpensive MTB wheels from Performance.

http://sheldonbrown.com/tire-sizing.html

If you have "standard" MB rims, you'll have no problem going to a 26x1.25". They are MADE for those rims.

You can fit a wide range of tire widths on your rims.

The skinnier your rims are the better they'll do with skinny tires.

The wider your rims are the better they'll do with wide tires.

Wide tires on skinny rims are no problem as long as you keep the pressure up. If you let the pressure get kinda low the tire will fold over on you in the turns.

Really wide rims make it tough get the beads of a really skinny tire to seat. You'll only find too-wide 26" rims on cruisers and freeride/downhill bikes for the most part, however.

And as another poster mentioned, make sure you get the right 26".
You want 559,
Not 590 or 597.

Ok so I guess that's more of a choice. I'll try to stick to whatever is available second hand and cheap and I should be ok =) as long as its not too wide or too skinny.

Second-hand? Just buy new tires, there are some reasonably-priced MTB slicks.

Second-hand? Just buy new tires, there are some reasonably-priced MTB slicks.

No point I only need them for another few months then I'm probably going to have to give the bike away since I'm mooving out of the country and the whole bike only costed 30€ also second hand ...

I did the same thing on one of my bikes. I got a 26x1.5 road tread tire and its MUCH better for zipping around town than roaring around on knobbies.

-SP

Yeah man I've done (asked the LBS) this to my Portuguese bike and I looked like superman peddling really fast but now with this other dutch bike I wanted to keep costs really down so decided to takle this modification on my own and got some really strange messages from the LBSs here :p I guess I should have done it myself to my other bike and now I would know what fits where =)