my tire looks flat when i rode it. it is fully inflated.
i have 26 1x3/8
planning to have bigger size. buying a new rim, inner tube and tire of course.

if 26 1.5 is bigger ill go for it.

sorry for the stupid question but i have limited knowledge in these things.


my weight is 88 kg / 190 ish lbs.


thanks.

First things first, you need to put more air in your tires if they look like that.

I have what are probably the fattest 26"x1-3/8" tires on one wheelset, and they measure no wider than 36-37mm. A lot of cheaper tires in that size are much narrower. 26"x1.5" tires would probably be a little bigger, but it would depend on the model.

1 3/8 is still that nasty old schwinn specific size, right? just get a new bike.

You say it's "fully inflated" but give no indication of the pressure. The picture looks like you don't have nearly enough pressure in it. It should be about 60 psi but varies a little between different tires.

Be careful about mixing fractional and decimal width tires, because they fit different rim diameters (bead seat diameter). A 26 X 1-3/8” tire will fit a rim with a 590mm BSD, whereas a 26 X 1.5” tire will fit a much smaller 559mm BSD.

Please look at the tire and find the ISO diameter. "26 x 1 3/8" was used on English style 3 speeds for a few decades (590mm), and on Schwinns in a slightly different size (597mm). Both are different from a 26in MTB wheel (559mm).

This.

The Schwinn tires are technically 26 X 1-1/4” to fit English EA-1 rims and Schwinn S-6 rims with a 597mm BSD. True 26 X 1-3/8” tires fit English EA-3 rims, aka 650A with a 590mm BSD. The most important difference is that the Schwinn compatible rims are open U with no hook, so maximum tire pressure is very low, typically 60 psi maximum. MTB rims and tires are good for much higher pressures.

Any 26 with a fractional size is not worth keeping around. Not only does the ISO diameter need to match so does the tire profile. Sometimes a tire with the correct ISO but a different tread pattern can actually be the wrong size and blow off a rim. The 26 size has 5 differentl ISO diameters.

https://www.sheldonbrown.com/26.html

As MotorheadsRoadie said just get a new bike it isn't worth messing with. You can and should inflate your tires properly but the odd fractional sizes aren't worth keeping around. 650B is worth it and ISO 559 are ok and are pretty common but the rest are silly.

The one in that picture, I was riding my bicycle, just to show you guys how flat looking my tire is.

In that picture, I was riding my bicycle, just to show you how flat it looks like when I sat on my bicycle.
So 26 1.5 is bigger?

The question remains, how much air did you have in your tire? It doesn't matter if you were riding it or not if it was underinflated.

i maxed it out, 70 psi.
thats the maximum, says in the side of the tire.


pumped it up 70 psi.


my question is 26 1.5 is wider than 26 1x3/8?

i maxed it out, 70 psi.
thats the maximum, says in the side of the tire.


pumped it up 70 psi.


my question is 26 1.5 is wider than 26 1x3/8? 10-24-17 05:44 PM

it’s about the same, however, it won’t fit on your rim as I explained previously. Your pressure gauge must be way off, because 70 psi should be more than sufficient for someone your weight on a tire that wide.

will buy new rim

Regardless, it won’t change anything if your tire is underinflated. Either that tire is NOT inflated anywhere near 70 psi, or you weigh a lot more than you said.

if this helps at all ... 1.5 = 1 1/2 (or 4/8") 3/8" is smaller

Your math is impeccable.

Unfortunately, nominal tire "sizes" don't correlate directly to actual measurements, unless you're looking at ETRTO, the only universal and mathematically accurate spec system.

You run into problems especially when comparing decimal to fractional specs. Please see Sheldon's page, linked in post #9 above.

I answered your question in my first post. "Maybe" is the best answer we can give without discussing individual tire models.

I share everyone else's skepticism that your tire is really pumped up to 70 psi. You should get a better pump, or see what happens when you pump up the rear tire to 80 psi.


P.S. Perhaps more to the point, going from a 1-3/8" tire to 1.5" will not improve your situation.

I'd agree that some oddball wheel sizes are too obscure to bother with, but 26"x1-3/8" (ISO 590) actually has decent support still. It just was never a high-performance wheel size (that I know of), so it flies under the radar.

While the ETRTO bead seat diameter numbers are fully reliable, the ETRTO widths are affected by rim width. E.g., this ETRTO 40-590 tire measures 36mm wide when mounted on a Sun CR-18 rim:

lol no, i weighted myself before ii rode the bike.
i dont think my weighing scale is broken too hehe.



my weight as of this time and day and year and this moment: 88kg

What I and others question is whether that tire is inflated to 70psi (about 5 Bar). It doesn't look like it's anywhere near that pressure.

it is, ive been telling ya all