Touring and tire pressure

[desben]

Hi,

I am preparing for my first touring trip. I plan on doing 600km over a 5-day period. I just bought and installed a rack today. I loaded my panniers with the luggage I plan on carrying to find it probably weights around 30lbs. All of this weight will be on the rear tire.

I use a road bike with 700x23 tires. I was wondering if you could advise me about what pressure I should put in the back tire to handle the extra weight? I usually keep both tires at 100psi.

Also, would you recommend installing a wider tire at the rear? I was thinking about a 700x25.

Many thanks!

[prestonjb]

How much extra weight? Or better still how much weight total?

I typically run 115-120psi on my 700x20s or 23s but then I'm only carrying an extra change of clothing on those trips.

Our tandem running with 700x23 at 120psi and two small packs is running with a weight just shy of 400lbs.

The wider tire will probably provide more comfort because you could run at a lower pressure (for a given weight).

But I would just suggest that if you normally don't get a lot of pinch flats with 100psi and your (body) weight is under 180lbs you should be OK. Or consider going to 115 but no more than 120psi.

[MidBunchLurker]

If you're going to stick with the 23 then run it at its max - probably around 115psi (check the sidewall). In the long run though, I think you'd be better off with a 25 or even 28. As prestonjb said, you'll be able to run them at a lower pressure, which will be good for your rear-end on the long hauls...

[desben]

I'll visit my LBS today to see what they have in 25mm. What's a good pressure for a 25mm? Around 100psi sounds good?

I'm 150lbs. For training, I keep my tires at 100psi because I feel it is faster. At 90psi, there's extra resistance. I've never gotten a pinch flat.

The total weight me-bike-luggage-water will be around 220lbs.

I realize I need slightly higher pressure to handle the extra weight. However, I was worried that 110psi + extra weight might put a lot of strain on the tire and it might blow up :eek: I always worry too much.