Hello,

I'm planning on buying road tires for my mountain bike and was wondering what would be the better option, as far as rolling resistance/speed is concerned.

One tire is 26" x 1.25, is 410gr and can be pumped up to 65 psi, the other tire is 26" x1.4, is 405gr and can be pumped up to 85 psi.

Any suggestions on what would be the better tire?

Thanks.

Would help to know the make / model of what you were looking at, then someone who has used them may be able to answer, too little info at the moment

One is Ritchey Tom Slick 26 x 1.4, 405gr and 85 psi max. The other is Tioga City Slicker 26 x 1.25, 410gr and 65psi max.

Of the 2, the Tom Slick, as it should offer a more comfortable ride due to being wider, and should be faster (less roll resistance) as you can inflate to a higher pressure.

Take it you are using these only on the road!

All things being equal, I'd go for the wider tire, which, of these two, also has the higher maximum pressure. Obviously cost is a consideration, but if the two are in a similar price range, and have similar smooth treads it's a no-brainer.

There's no need to go to max pressure, but 65psi is a bit skimpy for a 1.25" width tire, and unless you're very light may not give enough protection against sharp bumps like edges of potholes or driveway burms.

Here's a link to an article that will give you some insight in choosing the best tire width and pressure for your weight.