Effect of DH tire size?

Hey Lee,
Got a quick question about tire pressure. I’ve been running Kenda Blue Groove 2.7’s up front for years and wanted to switch to a 2.5 for racing. My problem arises when I try to run the 2.5 I cannot seem to find the correct pressure to work like the 2.7. My setup for the 2.7 is PSI = 18-20, for the 2.5 I’ve tried the same pressure, even a bit higher and lower but nothing works. With the 2.7 I can corner like mad, leaning the bike hard, but on the 2.5 my front washes, same trails, same riding position, same suspension setup, same everything, just different tire. What gives??? I’m at a loss! Thanks Lee.

Sincerely, David

Hey David,

A 2.5 will never perform the same as a 2.7.

A 2.7 has:

– 17% more volume. That means more shock absorption and more wiggle, which makes more traction.

– More contact with hard surfaces.

– More float on loose surfaces. This can be either good or bad.

– In different sizes, some tires have different block sizes and spacing. The 2.7 might have a better tread pattern for your conditions.

All that said, a 2.5 has:

– Less weight.

– Less rolling resistance, especially on harder surfaces.

– More penetration in loose surfaces.

– An overall quicker/livelier feel. I run 2.5s — I can’t say they hold me back at all.

These choices usually come down to riding style. You’re apparently more comfortable on a bigger tire. I say rock it. Increased confidence counts for a lot!

— Lee