Szerek

So, last night I went to the LBS and picked up my Sedona ST, brought it home and did a massive workout of a two mile ride. One of the things my son noticed was my back tire looked to be half flat. I'm sure I'd look half flat too with 390lbs pushing down me. Anyway, I checked the pressure this morning and both tires were at 45PSI. The tires that came stock on the bike are Kenda 50-559's which are rated from 40-65PSI.

I've been chatting with bautieri in PMs since yesterday and he's been a great help to me so far (seriously, thanks man!) but he thought maybe I should ask this question of the other uber clydes.

My questions are:

1) Will I risk blowing a sidewall on this tire at 65PSI at my weight. I know nothing of bike tires, but car tires can go far beyond their posted max PSI before they blow. I know of some crazy people that run car tires rated for 44 max PSI over 60 PSI. Are bike tires this way? Can I run at 65PSI without much worry of blowing the tire due to pressure?

2) Is there a better 26x1.95 tire out there for uber clydes (semi slick perferable) that can hold a higher pressure and result in less flex.

3) Any question I didn't ask here about tires, or pressure that I should have?

Thank you in advance. You've all been a tremendous help getting me started!

bautieri

You're welcome

Questions asked:

1: You aren't at any more risk of a side wall blow out. What you are more at risk of is a type of flat called a pinch flat or snake bite. What happens is that you run over a lip in the concrete or the edge of a pothole. All of your weight then pushes down and sandwiches the tube between the tire and rim. The rim itself then cuts the tube. It will look like two pin holes on the side of the tube, or a snake bite. I reccomend you inflate to 65-70psi and go for another ride before upgrading your tires. Don't go much above 70psi.

2: Don't limit yourself to the 26 x 1.95 size. You can go with a wider or narrower tire without trouble. The 26 referes to your rim size, and the other numbers refer to the width of your tire. Generally a narrower tire holds a higher PSI.

3: Yeah there is a question or two you probably missed , I think the biggest contributing factor to your saggy tires right now is being 20psi light. Inflate them fully and let us know if it gets any better.

Bau

cyclokitty 

I run my tires at max psi. When I ran similar sized tires as you, I pumped them up to 65 psi also. Now I have 26x1.75 that have a max of 70 psi which I find really comfortable even on my aluminum frame hybrid. You can always pump the front tire a bit softer to help reduce the road rattle running up your arms.

BigDaddyPedals

i run my tires at max.....i put 130psi in them.....when i attempted lower.....flats....but since high psi i've only had one flat and that was from a beer bottle that could not be avoided! i would for sure inflate to the max of 65psi for the tire.....good luck!

indyfabz

Years ago at Interbike I spoke with a rep. from Continental. He told me that the max. tire pressure rating on tires is nowhere near what would cause a sidewall blowout or cause the tire to blow off the rim.

AndrewP

Put 70 psi in the back and 55 in the front. Kenda Kross Plus Slick has a smooth centre section for easy rolling in straight line and treads on the sides for turning, but dont bother with this until the current ones are worn out.

CPFITNESS

100% inflate to max psi and check the pressure constantly. I was having a ton of trouble with flats from just running slightly under pressure but once i got a grasp on really keeping the pressure up, I was good.

Seattle Forrest

Bautieri is awesome!

For what it's worth, my tires are rated to something like 65 psi ( I'll go check if I get a chance ), but I run them at 110. Most folks at the local bike shop recommend about 90 for me, but after a lot of experimenting, 110 is my happy point. Beyond that, the road doesn't feel much better, and I start to get nervous; below that, there's more rolling resistance than I want for the long rides I enjoy.

I've been using 110 for around six months; the only flat I've had was because of a crash, where my back wheel heroically took the brunt of the impact for me. About 35 miles later, it sounded like a gun went off; the wire in the tire had come loose and punctured the tube. Anyway, I'm in the ballpark of 140 lbs less than you, so my numbers don't apply. But you probably want to experiment slowly the way I did. You'll hit a point where more air stops making your ride easier before you hit a point where you're likely to get a blowout. But be mindful of what you go over until you hit that point.

Szerek

Well, once again, thank you everone. My son and I went out and put another 3.1 miles on our bikes tonight. That's a mile more than I was able to ride yesterday! Putting the front and rear at 65 PSI made the ride easier. The tires didn't flex at all according to my boy.

One thing that has to go is the suspension seat post. When I set the seat at the right height to get full extension it is perfect. When I sit on it, it compresses and I can't get full extension. When I set it to get full extension when it is compressed I can't get on the damned bike.

Additionally, I would give a lot if our neighborhood roads were flat. They sure seem flat in the car, but on the bike, I can certainly tell you the aren't!

Seattle Forrest

Actually you kind of lucked out with the hills in your neighborhood, at least for bragging rights. I think the conversion is one hilly mile = as many flat miles as you want. So those 3.1 miles you did could equate to 30 if you want... Of course, it's kind of like solitaire, where you can cheat, but there isn't much point.

The air in the tire makes it a lot easier - cycling brought home some of those fuel efficiency tips for me. You want the back tire inflated, too, or you'll feel yourself want to fishtail on sharp curves. But it sounds like you're getting the hang of it.

I haven't had a seat suspension post, but I've had shocks on the front fork on a mountain bike once, and I've tried full suspension bikes. They're squishy! It's like you describe, only when you get out and start putting miles on the thing, a lot of your energy goes into pushing the suspension up and down, instead of moving you down the road. I bet the bike will get a little easier once you change that out. And if you're even slightly mechanically inclined, you might find someone on Craigslist to trade their rigid post for your "comfy" one?

Jtgyk

Suspension seatposts are evil.
You want to be able to raise up every once and awhile to relieve pressure on your nether-regions and the seat rises up with you maintaining contact....
evil
pure evil.

Szerek

I was eyeing my son's seat post on his Boulder SE. Sad thing is, his Boulder has a 30.2mm seat post and my Sedona has a 29.2. :