[i-ride]

what's the point in running a slightly narrower rear tire for XC riding? ie 2.3 front, 2.1 rear

 

[J_B]

My guess? Less overall weight. I don't see the point in running alittle bit less for trail riding.

 

[Ozzer]

My guess? Less overall weight. I don't see the point in running alittle bit less for trail riding.

On longer trail rides, it offers efficiency due to less drag (lesser contact patch). This is, btw, applicable only if you have a 2.1 or 2.0 raised center knob profile. Semi slicks and "square" profile tire are "relative."

My new fave setup on my trail/xc bike is a 2.3 Hutchinson Piranha XC Marathon (hard compound center and med compound sideknobs) and a rear 2.1 Hutchinson Barracuda
XC Marathon -UST Tubeless. The rear tire has a really high center knob proile -raised- while the side knobs are lower but flared for when you lean on corners. So far so good.

I had 2.3 f/r before but even with a hard compound in the 2.3 rear, the width and drag felt sluggish, most especially on the grinding climbs.

-orveh

 

[ukjason]

i suppose it something like your front tire which is slighty bigger makes the track and then your rear tyre which is narrower just flow through the front track with less contact

something like that i know what i mean

 

[shiggy]

what's the point in running a slightly narrower rear tire for XC riding? ie 2.3 front, 2.1 rear

No quick and easy answer. There can be any number of reasons:

Weight, traction, frame clearance,...

Depends on the rider, tires and bike.