Commuting - 26 x 1.25 tires on mountain bike wheels???

Hello, long time lurker with finally something worth asking that I could not find in the search. I just recently got into road biking, and my wife now wants to join me. My first bike was a cheap mountain bike that is collecting dust and will likely not be used for the mountain trails as I have a better mountain bike now for that.

So I'd like to convert my old MTB for my wife so she can have the best chance of keeping up with me on my road bike, and I'd like to keep it low budget for now. And I understand that swapping out the tires will probably be my best bet to help her with better speed since we will only be on paved trails. The tires on there now are a set of 26 x 1.95 tires.

My question is, can I run 26 x 1.25 tires on the old rims of my mtb? I talked with someone on the phone at Performance Bikes and they told me it would be too skinny, and to stick with 26 x 1.50 and up. But I read on one of the reviews that people have been able to put 26 x 1.25 on their old rims, is this feasible?

Is it possible the person on the phone didn't know what they were talking about? They steered me towards another set of tires that was a lot more money than the tires I was looking at, at this point, I don't want to invest a lot of money in the tires because i don't know if my wife will actually stick with it. If she does, she's getting a road bike like mine. I learned my lesson when I dropped a pretty penny on her golf clubs and gear when she thought she wanted to "join me" there as well, which, didn't really happen. lol

Sorry for the long winded question, thanks in advance.

ari b

Yes, it may be possible, depending on the rim size. Most older MTBs had "1.5 inch" rims, which have a <1.5" inner diameter. Look at Sheldon Brown's site for guidance: http://www.sheldonbrown.com/tire-sizing.html .

Don't overlook 1.5", I had done the same exact thing recently for my wife, and I was surprised how fast a 1.5" semi-slick tire will roll. The ride is definitely dominated by the geometry/fit of the bike, as it is more upright than my road bike. The rolling resistance doesn't really play into it too much for a relatively slick tire with higher pressure. She has no trouble getting up to 17-19 mph, but above that becomes tough because of the wind resistance.

There is also no reason why a 1.5" tire should be expensive. I have purchased both a set of these: http://www.amazon.com/gp/product/B00165P4Q8/ref=oss_product and a similar Kenda set in a LBS for $40. Both are very fast, and the limiting factor on the bikes are the positioning and gearing not the tires.

Welcome. I'd bet the tires will fit. I've got some 1.25s on normal MTB rims.
Buuuuuuuut...

So I'd like to convert my old MTB for my wife so she can have the best chance of keeping up with me on my road bike, and I'd like to keep it low budget for now...
Depending on how the ride goes, you stand a good chance of putting her off riding forever. Roll the dice.

If you really want her to keep up, let her ride the road bike while you slum it on the MTB.

Measure the inside diameter of your rims and report back for accurate advice on what will fit.

I put 1.25" tires on my mtn bike rims, didn't think twice about it, certainly didn't measure the rim width. Works like a charm. Rim might be narrower than yours, so YMMV.

Noobs tend to associate skinny tire with speed. My Michelin City 700x32 front/700x28 rear combo is only 1 mph slower than my Michelin Omron 700x23. Since I'm fit, the difference will be much less with your wife.

You can pick up the Michelin City (26x1.4) at Jenson. This outfit will price match. Note that the smaller width will result in a much harsher ride. Limit the tire pressure to 70 psi max. If there is $ to spare, then invest in a Brooks Flyer seat to smooth out the ride.

http://www.jensonusa.com/store/product/TI299D01-Michelin+City+Reflective+Strip+Tire.aspx

i converted my old MTB to a kid-trailer puller, got some schwalbe big apples to put on it , they are some fine and comfortable tires. got the 26 x 2.125 size but they have narrower sizes. if you look around the net you will find a lot of positive reviewes on these that is what led me to get them, they were about 40 bucks each but i figure they will last me a nice long time so worth the money.

Thanks guys.

My inside diameter of my rim is just shy of 1" using my tape measure. I'll be towing our daughter in a bike trailer and average 15mph on my road bike, so that should be enough for her to be able to keep pace. I had no intentions of leaving her behind or anything, I'm a better husband than that. :) And I really do want her to get a hang of riding so she can become more interested and ride with me. She is very fit is used to skating 25-30 miles on some of the trails were on. Putting her on my road bike is a no go as she is 5'2" and the bike is too big for her and she has never tried clipless pedals before. If it wasn't too big I would slap flats on it, but the geometry would be harder for her. The bike I am converting was a present from my wife over 10 years ago, but the guy helping her guided her to a bike that was too small for me, but it fits perfectly for her so that is why I am going to convert it to fit her. So far I have already got her a big gel seat and ergo grips, as well as tuned the bike. The tires will be the finishing touch. Later down the road I'll probably swap out the front suspension fork for a rigid fork to make it a tad bit lighter.

The trail I plan to take her on is very flat, and completely paved the whole way. I'll start her on an easy pace with a target of 10-15 miles. It's going to be a nice weekend, so we plan to go late Sunday evening.

Sorry for what may sound as a "silly" question, we are all "noobs" at something at one point or another. As a firearms and safety instructor I deal with it every day with that in mind.

cheers

I've had god luck with the geax street runners 1.6's. about $22.

I put a set of Forte Metro K tires in 26 x 1.25 on my wife's old comfort bike and she was amazed how much better it rode on the street (old tires were 26 x 1.95). They run around $15 at Performance Bike Shop.

when i converted my old mountain bike into a commuter, i put some 26 x 1.35 marathon pluses on the rims and they work just fine together. i would imagine going down to 1.25 would be no issue either.

There's a good chance it should work. In fact, as long as the tires are wider than the internal diameter of the rims, you should be ok. To be safe, you have to take off the tire and measure between the two bead seats. If that measurement is 1 inch, like you said, you should be fine.

It should work fine, but I find that casual riders prefer 1.5s. They can be a little lower pressure (better traction) and look more stable (psychology and confidence are huge). My 2c.

I've put 1.25's on 26" MTB rims but it definitely depends on the rim and the tire itself. Tire manufacturers seem to vary the bead enough that some tires may fit and some may not. Personally I think the 1.5's give an all around better ride- not quite as speedy but a bit more comfort and a bit more of the right overall tire/wheel circumference for the geometry of the frame. Just make sure they are pumped up to the max. pressure on the sidewall.

Depends on the rim width.

If your rim is between 17mm and 23mm wide, (this measurement is inside width, not outside width) you will be ok. All things considered, it is probably a safe bet that your rims fall within this range. 1 inch = 25.4mm

Short answer, you should be fine.

Note, I've attached a link to a page on our website where one can cross-reference what tire sizes will fit on which rims. This page also includes a diagram defining bicycle rim width and diameter measurements.

http://www.schwalbetires.com/tech_info/tire_dimensions

My inside diameter of my rim is just shy of 1" using my tape measure.

If this is an accurate measurement, I'd probably go with something more like 26x1.6.

I hate to question you again :D but that's a pretty wide rim. I've got a couple of MTB wheel sets in my garage, and their outside width ranges from about 25mm (the stock wheels on my daughter's old RockHopper) to 22.5mm (the Salsa Delgados on my Muirwoods 29er). Inside width is usually about 5 mm narrower. A relatively new rim, designed for the 26x2.35 and wider tires that are now common would be as wide as you describe, but the 26x1.95 tire you mentioned seems to point in a different direction.

Obviously, a tape measure isn't the best tool for this job and a measurement in millimeters is ideal, but (also obviously) we work with what we have.

You may be OK with 1.25, but at 15 mph, I don't think she'd suffer with wider tires. Check out the Michelin Country Rock (http://www.universalcycles.com/shopping/product_details.php?id=7574&category=191). They're dirt cheap and get great reviews.